Patient & Survivor Care

The results of a large French study comparing the cancer risk in children conceived through assisted reproductive technology (ART) with that of naturally conceived children were published recently in JAMA Network Open. This study is one of the largest to date on this subject: It included 8,526,306 children born in France between 2010 and 2021, of whom 260,236 (3%) were conceived through ART, and followed them up to a median age of 6.7 years.

Motivations for the Study

ART (including artificial insemination, in vitro fertilization [IVF], or intracytoplasmic sperm injection [ICSI] with fresh or frozen embryo transfer) accounts for about 1 in 30 births in France. However, limited and heterogeneous data have suggested an increased risk for certain health disorders, including cancer, among children conceived through ART. Therefore, a large-scale evaluation of cancer risk in these children is important.

No Overall Increase

In all, 9256 children developed cancer, including 292 who were conceived through ART. Thus, this study did not show an increased risk for cancer (of all types combined) in children conceived through ART. Nevertheless, a slight increase in the risk for leukemia was observed in children conceived through IVF or ICSI. The investigators observed approximately one additional case for every 5000 newborns conceived through IVF or ICSI who reached age 10 years.

Epidemiological monitoring should be continued to better evaluate long-term risks and see whether the risk for leukemia is confirmed. If it is, then it will be useful to investigate the mechanisms related to ART techniques or the fertility disorders of parents that could lead to an increased risk for leukemia.

This story was translated from Univadis France, which is part of the Medscape Professional Network, using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.

The results of a large French study comparing the cancer risk in children conceived through assisted reproductive technology (ART) with that of naturally conceived children were published recently in JAMA Network Open. This study is one of the largest to date on this subject: It included 8,526,306 children born in France between 2010 and 2021, of whom 260,236 (3%) were conceived through ART, and followed them up to a median age of 6.7 years.

Motivations for the Study

ART (including artificial insemination, in vitro fertilization [IVF], or intracytoplasmic sperm injection [ICSI] with fresh or frozen embryo transfer) accounts for about 1 in 30 births in France. However, limited and heterogeneous data have suggested an increased risk for certain health disorders, including cancer, among children conceived through ART. Therefore, a large-scale evaluation of cancer risk in these children is important.

No Overall Increase

In all, 9256 children developed cancer, including 292 who were conceived through ART. Thus, this study did not show an increased risk for cancer (of all types combined) in children conceived through ART. Nevertheless, a slight increase in the risk for leukemia was observed in children conceived through IVF or ICSI. The investigators observed approximately one additional case for every 5000 newborns conceived through IVF or ICSI who reached age 10 years.

Epidemiological monitoring should be continued to better evaluate long-term risks and see whether the risk for leukemia is confirmed. If it is, then it will be useful to investigate the mechanisms related to ART techniques or the fertility disorders of parents that could lead to an increased risk for leukemia.

This story was translated from Univadis France, which is part of the Medscape Professional Network, using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.

The results of a large French study comparing the cancer risk in children conceived through assisted reproductive technology (ART) with that of naturally conceived children were published recently in JAMA Network Open. This study is one of the largest to date on this subject: It included 8,526,306 children born in France between 2010 and 2021, of whom 260,236 (3%) were conceived through ART, and followed them up to a median age of 6.7 years.

Motivations for the Study

ART (including artificial insemination, in vitro fertilization [IVF], or intracytoplasmic sperm injection [ICSI] with fresh or frozen embryo transfer) accounts for about 1 in 30 births in France. However, limited and heterogeneous data have suggested an increased risk for certain health disorders, including cancer, among children conceived through ART. Therefore, a large-scale evaluation of cancer risk in these children is important.

No Overall Increase

In all, 9256 children developed cancer, including 292 who were conceived through ART. Thus, this study did not show an increased risk for cancer (of all types combined) in children conceived through ART. Nevertheless, a slight increase in the risk for leukemia was observed in children conceived through IVF or ICSI. The investigators observed approximately one additional case for every 5000 newborns conceived through IVF or ICSI who reached age 10 years.

Epidemiological monitoring should be continued to better evaluate long-term risks and see whether the risk for leukemia is confirmed. If it is, then it will be useful to investigate the mechanisms related to ART techniques or the fertility disorders of parents that could lead to an increased risk for leukemia.

This story was translated from Univadis France, which is part of the Medscape Professional Network, using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.

BOSTON — Nearly one in five breast cancer survivors will gain more than 10% of their body weight in the 6 years following their diagnosis, according to new research presented at ENDO 2024, the annual meeting of the Endocrine Society.

Younger age and lower weight at diagnosis were the strongest predictors of this excessive weight gain over time. 

“Weight gain is a common concern after breast cancer diagnosis and treatment,” said Maria Daniela Hurtado Andrade, MD, PhD, of the Mayo Clinic in Jacksonville, Florida, who led the research. “This weight gain in breast cancer survivor increases breast cancer recurrence and mortality, increases cardiovascular disease and mortality, and also increases all-cause mortality.”

Previous studies have found an association between breast cancer survivorship and weight gain, but the reported incidences of weight gain — and the amounts gained — have been highly variable, she added.

In the study, researchers used the Mayo Clinic Breast Cancer Registry to identify 4575 breast cancer survivors and tracked their weight over the course of 6 years following cancer diagnosis. These patients were age-matched to women in the general population selected from the Rochester Epidemiology Project, which contains the medical records of residents of 27 counties in Minnesota and Wisconsin. All controls had no history of cancer or bariatric surgery.

Nearly all patients and controls were White (97%); at breast cancer diagnosis, patients were on average 58 years of age and weighed 76 kg (165.5 lb). Controls had similar ages and baseline weights.

At 6 years following breast cancer diagnosis, average weight gain was modest: Breast cancer survivors gained 1.6% of their body weight, compared with 0.7% in controls (P = .004).

However, 18% of breast cancer survivors had gained at least 10% of their body weight over that time. By comparison, 8% of controls experienced this excessive weight gain during that same time frame (P < .0001). The same trend was observed for 15% and 20% weight gain.

After adjustment for confounding factors, younger age at breast cancer diagnosis and lower baseline weight were the strongest predictors of more than 10% weight gain. BRCA2 mutation and use of systemic chemotherapy treatment were also associated with excessive weight gain.

Several factors could be driving weight gain in these patients, said Zeynep Madak-Erdogan, PhD, at the University of Illinois Urbana-Champaign, who was not involved with the research. Her work focuses on how diet and nutrition affect hormone action in postmenopausal women and breast cancer survivors. Certain therapies can induce temporary or permanent menopause in patients, “and this early menopause might shift balance of estrogens and cause increased weight gain,” she said. Along the same lines, endocrine therapies can also affect estrogen production. 

Stress and exhaustion from treatment — especially compounded by the two previous factors — are also likely culprits in weight gain, she continued.

“These findings highlight importance of lifestyle interventions,” added Dr. Madak-Erdogan. “In addition to changes in the diet (increased vegetable, fruit, [and] whole grain intake; reduction in saturated fats, alcohol, [and] sweetened beverage consumption), survivors should be consulted on importance of regular exercise.”

“These data clearly show we must consider weight changes in breast cancer survivors, and we must find ways of instituting strategies to mitigate these weight gains,” Dr. Hurtado Andrade said. “These women have a lot to think of when they have a breast cancer diagnosis, so we also must find ways of instituting these measures in a way that doesn’t increase the burden of their health.”

Dr. Hurtado Andrade has received research funding from the National Institutes of Health and by Phenomix Sciences. She also is a consultant for Novo Nordisk. These three organizations were not involved with this study. Dr. Madak-Erdogan had no disclosures.

A version of this article first appeared on Medscape.com.

BOSTON — Nearly one in five breast cancer survivors will gain more than 10% of their body weight in the 6 years following their diagnosis, according to new research presented at ENDO 2024, the annual meeting of the Endocrine Society.

Younger age and lower weight at diagnosis were the strongest predictors of this excessive weight gain over time. 

“Weight gain is a common concern after breast cancer diagnosis and treatment,” said Maria Daniela Hurtado Andrade, MD, PhD, of the Mayo Clinic in Jacksonville, Florida, who led the research. “This weight gain in breast cancer survivor increases breast cancer recurrence and mortality, increases cardiovascular disease and mortality, and also increases all-cause mortality.”

Previous studies have found an association between breast cancer survivorship and weight gain, but the reported incidences of weight gain — and the amounts gained — have been highly variable, she added.

In the study, researchers used the Mayo Clinic Breast Cancer Registry to identify 4575 breast cancer survivors and tracked their weight over the course of 6 years following cancer diagnosis. These patients were age-matched to women in the general population selected from the Rochester Epidemiology Project, which contains the medical records of residents of 27 counties in Minnesota and Wisconsin. All controls had no history of cancer or bariatric surgery.

Nearly all patients and controls were White (97%); at breast cancer diagnosis, patients were on average 58 years of age and weighed 76 kg (165.5 lb). Controls had similar ages and baseline weights.

At 6 years following breast cancer diagnosis, average weight gain was modest: Breast cancer survivors gained 1.6% of their body weight, compared with 0.7% in controls (P = .004).

However, 18% of breast cancer survivors had gained at least 10% of their body weight over that time. By comparison, 8% of controls experienced this excessive weight gain during that same time frame (P < .0001). The same trend was observed for 15% and 20% weight gain.

After adjustment for confounding factors, younger age at breast cancer diagnosis and lower baseline weight were the strongest predictors of more than 10% weight gain. BRCA2 mutation and use of systemic chemotherapy treatment were also associated with excessive weight gain.

Several factors could be driving weight gain in these patients, said Zeynep Madak-Erdogan, PhD, at the University of Illinois Urbana-Champaign, who was not involved with the research. Her work focuses on how diet and nutrition affect hormone action in postmenopausal women and breast cancer survivors. Certain therapies can induce temporary or permanent menopause in patients, “and this early menopause might shift balance of estrogens and cause increased weight gain,” she said. Along the same lines, endocrine therapies can also affect estrogen production. 

Stress and exhaustion from treatment — especially compounded by the two previous factors — are also likely culprits in weight gain, she continued.

“These findings highlight importance of lifestyle interventions,” added Dr. Madak-Erdogan. “In addition to changes in the diet (increased vegetable, fruit, [and] whole grain intake; reduction in saturated fats, alcohol, [and] sweetened beverage consumption), survivors should be consulted on importance of regular exercise.”

“These data clearly show we must consider weight changes in breast cancer survivors, and we must find ways of instituting strategies to mitigate these weight gains,” Dr. Hurtado Andrade said. “These women have a lot to think of when they have a breast cancer diagnosis, so we also must find ways of instituting these measures in a way that doesn’t increase the burden of their health.”

Dr. Hurtado Andrade has received research funding from the National Institutes of Health and by Phenomix Sciences. She also is a consultant for Novo Nordisk. These three organizations were not involved with this study. Dr. Madak-Erdogan had no disclosures.

A version of this article first appeared on Medscape.com.

BOSTON — Nearly one in five breast cancer survivors will gain more than 10% of their body weight in the 6 years following their diagnosis, according to new research presented at ENDO 2024, the annual meeting of the Endocrine Society.

Younger age and lower weight at diagnosis were the strongest predictors of this excessive weight gain over time. 

“Weight gain is a common concern after breast cancer diagnosis and treatment,” said Maria Daniela Hurtado Andrade, MD, PhD, of the Mayo Clinic in Jacksonville, Florida, who led the research. “This weight gain in breast cancer survivor increases breast cancer recurrence and mortality, increases cardiovascular disease and mortality, and also increases all-cause mortality.”

Previous studies have found an association between breast cancer survivorship and weight gain, but the reported incidences of weight gain — and the amounts gained — have been highly variable, she added.

In the study, researchers used the Mayo Clinic Breast Cancer Registry to identify 4575 breast cancer survivors and tracked their weight over the course of 6 years following cancer diagnosis. These patients were age-matched to women in the general population selected from the Rochester Epidemiology Project, which contains the medical records of residents of 27 counties in Minnesota and Wisconsin. All controls had no history of cancer or bariatric surgery.

Nearly all patients and controls were White (97%); at breast cancer diagnosis, patients were on average 58 years of age and weighed 76 kg (165.5 lb). Controls had similar ages and baseline weights.

At 6 years following breast cancer diagnosis, average weight gain was modest: Breast cancer survivors gained 1.6% of their body weight, compared with 0.7% in controls (P = .004).

However, 18% of breast cancer survivors had gained at least 10% of their body weight over that time. By comparison, 8% of controls experienced this excessive weight gain during that same time frame (P < .0001). The same trend was observed for 15% and 20% weight gain.

After adjustment for confounding factors, younger age at breast cancer diagnosis and lower baseline weight were the strongest predictors of more than 10% weight gain. BRCA2 mutation and use of systemic chemotherapy treatment were also associated with excessive weight gain.

Several factors could be driving weight gain in these patients, said Zeynep Madak-Erdogan, PhD, at the University of Illinois Urbana-Champaign, who was not involved with the research. Her work focuses on how diet and nutrition affect hormone action in postmenopausal women and breast cancer survivors. Certain therapies can induce temporary or permanent menopause in patients, “and this early menopause might shift balance of estrogens and cause increased weight gain,” she said. Along the same lines, endocrine therapies can also affect estrogen production. 

Stress and exhaustion from treatment — especially compounded by the two previous factors — are also likely culprits in weight gain, she continued.

“These findings highlight importance of lifestyle interventions,” added Dr. Madak-Erdogan. “In addition to changes in the diet (increased vegetable, fruit, [and] whole grain intake; reduction in saturated fats, alcohol, [and] sweetened beverage consumption), survivors should be consulted on importance of regular exercise.”

“These data clearly show we must consider weight changes in breast cancer survivors, and we must find ways of instituting strategies to mitigate these weight gains,” Dr. Hurtado Andrade said. “These women have a lot to think of when they have a breast cancer diagnosis, so we also must find ways of instituting these measures in a way that doesn’t increase the burden of their health.”

Dr. Hurtado Andrade has received research funding from the National Institutes of Health and by Phenomix Sciences. She also is a consultant for Novo Nordisk. These three organizations were not involved with this study. Dr. Madak-Erdogan had no disclosures.

A version of this article first appeared on Medscape.com.

The antibody-drug conjugate trastuzumab deruxtecan, or T-DXd, is an effective first-line treatment in patients with HER2-low metastatic breast cancer, conferring an additional 5 months’ progression-free survival over chemotherapy.

HER2-low cancers express levels of human epidermal growth factor receptor 2 that are below standard thresholds for HER2-positive immunohistochemistry. In 2022, results from the DESTINY-Breast04 trial showed T-DXd (Enhertu, AstraZeneca) to be an effective second-line chemotherapy in patients with HER2-low metastatic breast cancer.

The highly awaited new findings, from the manufacturer-sponsored, open-label Phase 3 DESTINY-Breast06 trial, were presented at the annual meeting of the American Society of Clinical Oncology (ASCO) in Chicago, Illinois.

The findings not only definitively establish a role for T-DXd earlier in the treatment sequence for HER2-low cancers, they also suggest benefit in a group of patients designated for the purposes of this trial to be HER2-ultralow. These patients have cancers with only faintly detectable HER2 expression on currently used assays (J Clin Oncol 42, 2024 [suppl 17; abstr LBA 1000]).

In a separate set of findings also presented at ASCO, from the randomized phase 1B open-label study, DESTINY-Breast07, T-Dxd showed efficacy in previously untreated HER2-positive metastatic breast cancer patients both alone and in combination with the monoclonal antibody pertuzumab (Perjeta, Genentech).
 

DESTINY-Breast06 Methods and Results

The DESTINY-Breast06 findings were presented by lead investigator Guiseppe Curigliano, MD, PhD, of the University of Milan and European Institute of Oncology. Dr. Curigliano and his colleagues randomized 866 patients with metastatic breast cancer: 436 to intravenous T-Dxd and 430 to the investigator’s choice of capecitabine, nab-paclitaxel, or paclitaxel chemotherapy. The investigators chose capecitabine 60% of the time.

Most patients had cancers classed as HER2 low (immunohistochemistry 1+ or 2+), while 153 had cancers classed by investigators as HER2-ultralow (IHC 0 with membrane staining or IHC under 1+). Patients enrolled in the study were those whose disease had progressed after endocrine therapy with or without targeted therapy. Patients’ median age was between 57 and 58, and all were chemotherapy-naive in the metastatic breast cancer setting.

The main outcome of the study was median progression-free survival in the HER2-low group. T-Dxd was seen improving progression-free survival, with median 13.2 months vs. 8.1 months (hazard ratio, 0.62; 95% confidence interval, 0.51-0.74; P < .0001). In the intention-to-treat population, which included the HER2 ultralow patients, the benefit was the same (HR, 0.63; 95% CI, 0.53-0.75; P < .0001). This suggested that T-DXd is also effective in these patients, and it will be extremely important going forward to identify the lowest level of HER2 expression in metastatic breast cancers that can still benefit from therapy with T-DxD, Dr. Curigliano said.

Overall survival could not be assessed in the study cohort because complete data were not yet available, Dr. Curigliano said. However, trends pointed to an advantage for T-DXd, and tumor response rates were markedly higher with T-DXd: 57% compared with 31% for standard chemotherapy in the full cohort.

Serious treatment-emergent adverse events were more common in the T-Dxd–treated patients, with 11% of that arm developing drug-related interstitial lung disease, and three patients dying of it. Five patients in the T-DXd arm died of adverse events deemed treatment-related, and none died from treatment-related adverse events in the standard chemotherapy arm. Altogether 11 patients died in the T-DXd arm and 6 in the chemotherapy arm.
 

Clinical Implications of DESTINY-Breast06

The DESTINY-Breast06 data show that “we have to again change how we think about HER2 expression. Even very low levels of HER2 expression matter, and they can be leveraged to improve the treatment for our patients,” said Ian Krop, MD, PhD, of the Yale Cancer Center in New Haven, Connecticut, during the session where the results were presented.

But T-DXd may not be an appropriate first choice for all patients, especially given the safety concerns associated with T-DXd, he continued. With overall survival and quality-of-life data still lacking, clinicians will have to determine on a case-by-case basis who should get T-DXd in the first line.

“For patients who have symptomatic metastatic disease, who need a response to address those symptoms, those in whom you think chemotherapy may not work as well because they had, for example, a short recurrence interval after their adjuvant chemotherapy — using T-DXd in that first-line setting makes perfect sense to take advantage of the substantially higher response rate compared to chemo,” Dr. Krop said. “But for patients who have asymptomatic low burdens of disease, it seems very reasonable to consider using a well-tolerated chemotherapy like capecitabine in the first line, and then using T-DXd in the second line.”

In an interview, Erica Mayer, MD, of the Dana Farber Cancer Institute in Boston, Massachusetts, said patient choice will also matter in determining whether T-DXd is a first-line option. The known toxicity of T-DXd was underscored by the latest findings, she noted, while capecitabine, one of the chemotherapy choices in the control arm of the study, “really reflects what the majority of breast cancer doctors tend to offer, both because of the efficacy of the drug, but also because it’s oral, it’s well tolerated, and you don’t lose your hair.”
 

DESTINY-Breast07 Results

The DESTINY-Breast07 findings, from a Phase 1B open-label trial measuring safety and tolerability, were presented by Fabrice Andre, MD, PhD, of Université Paris Saclay in Paris, France. Dr. Andre and his colleagues presented the first data comparing T-DXd monotherapy and T-DXd with pertuzumab — a monoclonal antibody targeting HER2 — as a first-line treatment in patients with HER2-overexpressing (immunohistochemistry 3 and above) metastatic breast cancer. (J Clin Oncol 42, 2024 [suppl 16; abstr 1009]).

Current first-line standard of care for these patients is pertuzumab, trastuzumab, and docetaxel, based on results from the 2015 CLEOPATRA trial. T-DXd is currently approved as a second-line treatment.

Dr. Andre and his colleagues randomized 75 patients to monotherapy with T-DXd and 50 to combined therapy, with a median follow-up of 2 years.

After 1 year of treatment, combination of T-DXd and pertuzumab was seen to be associated with a progression-free survival of 89% at 1 year (80% CI, 81.9-93.9), compared with 80% in patients treated with T-DXd alone (80% CI, 73.7-86.1). Objective tumor response rate was 84% for the combined therapy at 12 weeks, with 20% of patients seeing a complete response, compared with 76% and 8%, respectively, for monotherapy.

As in the DESTINY-Breast06 trial, adverse events were high, with interstitial lung disease seen in 9% of patients in the monotherapy group and in 14% of the combined-therapy patients, although no treatment-related deaths occurred.

A randomized phase 3 trial, DESTINY Breast09, will now compare the monotherapy and the combined therapy with standard care.

T-DXd has seen a rapidly expanding role in treating breast and other solid tumors. The DESTINY Breast06 findings will move up its place in the treatment algorithm for metastatic breast cancer, “allowing us to now offer T-DXd as the first chemotherapy choice for patients who are making that transition to chemotherapy over many of the traditional provider choices that we previously have offered,” Dr. Mayer said.

The results “support the use of not only this specific agent, but also the concept of antibody drug conjugates as a very effective way to treat malignancy,” she added.

Dr. Curigliano reported receiving speaker’s fees, research funding, and other support from AstraZeneca and Daiichi Sankyo, among other companies, as did most of his co-authors, of whom three were AstraZeneca employees. Dr. Fabrice disclosed receiving research funding, travel compensation, and/or advisory fees from AstraZeneca and other entities, as did several of his co-authors. Two of his co-authors were employed by AstraZeneca and Roche, manufacturers of the study drugs. Dr. Krop and Dr. Mayer disclosed relationships with AstraZeneca and others.

The antibody-drug conjugate trastuzumab deruxtecan, or T-DXd, is an effective first-line treatment in patients with HER2-low metastatic breast cancer, conferring an additional 5 months’ progression-free survival over chemotherapy.

HER2-low cancers express levels of human epidermal growth factor receptor 2 that are below standard thresholds for HER2-positive immunohistochemistry. In 2022, results from the DESTINY-Breast04 trial showed T-DXd (Enhertu, AstraZeneca) to be an effective second-line chemotherapy in patients with HER2-low metastatic breast cancer.

The highly awaited new findings, from the manufacturer-sponsored, open-label Phase 3 DESTINY-Breast06 trial, were presented at the annual meeting of the American Society of Clinical Oncology (ASCO) in Chicago, Illinois.

The findings not only definitively establish a role for T-DXd earlier in the treatment sequence for HER2-low cancers, they also suggest benefit in a group of patients designated for the purposes of this trial to be HER2-ultralow. These patients have cancers with only faintly detectable HER2 expression on currently used assays (J Clin Oncol 42, 2024 [suppl 17; abstr LBA 1000]).

In a separate set of findings also presented at ASCO, from the randomized phase 1B open-label study, DESTINY-Breast07, T-Dxd showed efficacy in previously untreated HER2-positive metastatic breast cancer patients both alone and in combination with the monoclonal antibody pertuzumab (Perjeta, Genentech).
 

DESTINY-Breast06 Methods and Results

The DESTINY-Breast06 findings were presented by lead investigator Guiseppe Curigliano, MD, PhD, of the University of Milan and European Institute of Oncology. Dr. Curigliano and his colleagues randomized 866 patients with metastatic breast cancer: 436 to intravenous T-Dxd and 430 to the investigator’s choice of capecitabine, nab-paclitaxel, or paclitaxel chemotherapy. The investigators chose capecitabine 60% of the time.

Most patients had cancers classed as HER2 low (immunohistochemistry 1+ or 2+), while 153 had cancers classed by investigators as HER2-ultralow (IHC 0 with membrane staining or IHC under 1+). Patients enrolled in the study were those whose disease had progressed after endocrine therapy with or without targeted therapy. Patients’ median age was between 57 and 58, and all were chemotherapy-naive in the metastatic breast cancer setting.

The main outcome of the study was median progression-free survival in the HER2-low group. T-Dxd was seen improving progression-free survival, with median 13.2 months vs. 8.1 months (hazard ratio, 0.62; 95% confidence interval, 0.51-0.74; P < .0001). In the intention-to-treat population, which included the HER2 ultralow patients, the benefit was the same (HR, 0.63; 95% CI, 0.53-0.75; P < .0001). This suggested that T-DXd is also effective in these patients, and it will be extremely important going forward to identify the lowest level of HER2 expression in metastatic breast cancers that can still benefit from therapy with T-DxD, Dr. Curigliano said.

Overall survival could not be assessed in the study cohort because complete data were not yet available, Dr. Curigliano said. However, trends pointed to an advantage for T-DXd, and tumor response rates were markedly higher with T-DXd: 57% compared with 31% for standard chemotherapy in the full cohort.

Serious treatment-emergent adverse events were more common in the T-Dxd–treated patients, with 11% of that arm developing drug-related interstitial lung disease, and three patients dying of it. Five patients in the T-DXd arm died of adverse events deemed treatment-related, and none died from treatment-related adverse events in the standard chemotherapy arm. Altogether 11 patients died in the T-DXd arm and 6 in the chemotherapy arm.
 

Clinical Implications of DESTINY-Breast06

The DESTINY-Breast06 data show that “we have to again change how we think about HER2 expression. Even very low levels of HER2 expression matter, and they can be leveraged to improve the treatment for our patients,” said Ian Krop, MD, PhD, of the Yale Cancer Center in New Haven, Connecticut, during the session where the results were presented.

But T-DXd may not be an appropriate first choice for all patients, especially given the safety concerns associated with T-DXd, he continued. With overall survival and quality-of-life data still lacking, clinicians will have to determine on a case-by-case basis who should get T-DXd in the first line.

“For patients who have symptomatic metastatic disease, who need a response to address those symptoms, those in whom you think chemotherapy may not work as well because they had, for example, a short recurrence interval after their adjuvant chemotherapy — using T-DXd in that first-line setting makes perfect sense to take advantage of the substantially higher response rate compared to chemo,” Dr. Krop said. “But for patients who have asymptomatic low burdens of disease, it seems very reasonable to consider using a well-tolerated chemotherapy like capecitabine in the first line, and then using T-DXd in the second line.”

In an interview, Erica Mayer, MD, of the Dana Farber Cancer Institute in Boston, Massachusetts, said patient choice will also matter in determining whether T-DXd is a first-line option. The known toxicity of T-DXd was underscored by the latest findings, she noted, while capecitabine, one of the chemotherapy choices in the control arm of the study, “really reflects what the majority of breast cancer doctors tend to offer, both because of the efficacy of the drug, but also because it’s oral, it’s well tolerated, and you don’t lose your hair.”
 

DESTINY-Breast07 Results

The DESTINY-Breast07 findings, from a Phase 1B open-label trial measuring safety and tolerability, were presented by Fabrice Andre, MD, PhD, of Université Paris Saclay in Paris, France. Dr. Andre and his colleagues presented the first data comparing T-DXd monotherapy and T-DXd with pertuzumab — a monoclonal antibody targeting HER2 — as a first-line treatment in patients with HER2-overexpressing (immunohistochemistry 3 and above) metastatic breast cancer. (J Clin Oncol 42, 2024 [suppl 16; abstr 1009]).

Current first-line standard of care for these patients is pertuzumab, trastuzumab, and docetaxel, based on results from the 2015 CLEOPATRA trial. T-DXd is currently approved as a second-line treatment.

Dr. Andre and his colleagues randomized 75 patients to monotherapy with T-DXd and 50 to combined therapy, with a median follow-up of 2 years.

After 1 year of treatment, combination of T-DXd and pertuzumab was seen to be associated with a progression-free survival of 89% at 1 year (80% CI, 81.9-93.9), compared with 80% in patients treated with T-DXd alone (80% CI, 73.7-86.1). Objective tumor response rate was 84% for the combined therapy at 12 weeks, with 20% of patients seeing a complete response, compared with 76% and 8%, respectively, for monotherapy.

As in the DESTINY-Breast06 trial, adverse events were high, with interstitial lung disease seen in 9% of patients in the monotherapy group and in 14% of the combined-therapy patients, although no treatment-related deaths occurred.

A randomized phase 3 trial, DESTINY Breast09, will now compare the monotherapy and the combined therapy with standard care.

T-DXd has seen a rapidly expanding role in treating breast and other solid tumors. The DESTINY Breast06 findings will move up its place in the treatment algorithm for metastatic breast cancer, “allowing us to now offer T-DXd as the first chemotherapy choice for patients who are making that transition to chemotherapy over many of the traditional provider choices that we previously have offered,” Dr. Mayer said.

The results “support the use of not only this specific agent, but also the concept of antibody drug conjugates as a very effective way to treat malignancy,” she added.

Dr. Curigliano reported receiving speaker’s fees, research funding, and other support from AstraZeneca and Daiichi Sankyo, among other companies, as did most of his co-authors, of whom three were AstraZeneca employees. Dr. Fabrice disclosed receiving research funding, travel compensation, and/or advisory fees from AstraZeneca and other entities, as did several of his co-authors. Two of his co-authors were employed by AstraZeneca and Roche, manufacturers of the study drugs. Dr. Krop and Dr. Mayer disclosed relationships with AstraZeneca and others.

The antibody-drug conjugate trastuzumab deruxtecan, or T-DXd, is an effective first-line treatment in patients with HER2-low metastatic breast cancer, conferring an additional 5 months’ progression-free survival over chemotherapy.

HER2-low cancers express levels of human epidermal growth factor receptor 2 that are below standard thresholds for HER2-positive immunohistochemistry. In 2022, results from the DESTINY-Breast04 trial showed T-DXd (Enhertu, AstraZeneca) to be an effective second-line chemotherapy in patients with HER2-low metastatic breast cancer.

The highly awaited new findings, from the manufacturer-sponsored, open-label Phase 3 DESTINY-Breast06 trial, were presented at the annual meeting of the American Society of Clinical Oncology (ASCO) in Chicago, Illinois.

The findings not only definitively establish a role for T-DXd earlier in the treatment sequence for HER2-low cancers, they also suggest benefit in a group of patients designated for the purposes of this trial to be HER2-ultralow. These patients have cancers with only faintly detectable HER2 expression on currently used assays (J Clin Oncol 42, 2024 [suppl 17; abstr LBA 1000]).

In a separate set of findings also presented at ASCO, from the randomized phase 1B open-label study, DESTINY-Breast07, T-Dxd showed efficacy in previously untreated HER2-positive metastatic breast cancer patients both alone and in combination with the monoclonal antibody pertuzumab (Perjeta, Genentech).
 

DESTINY-Breast06 Methods and Results

The DESTINY-Breast06 findings were presented by lead investigator Guiseppe Curigliano, MD, PhD, of the University of Milan and European Institute of Oncology. Dr. Curigliano and his colleagues randomized 866 patients with metastatic breast cancer: 436 to intravenous T-Dxd and 430 to the investigator’s choice of capecitabine, nab-paclitaxel, or paclitaxel chemotherapy. The investigators chose capecitabine 60% of the time.

Most patients had cancers classed as HER2 low (immunohistochemistry 1+ or 2+), while 153 had cancers classed by investigators as HER2-ultralow (IHC 0 with membrane staining or IHC under 1+). Patients enrolled in the study were those whose disease had progressed after endocrine therapy with or without targeted therapy. Patients’ median age was between 57 and 58, and all were chemotherapy-naive in the metastatic breast cancer setting.

The main outcome of the study was median progression-free survival in the HER2-low group. T-Dxd was seen improving progression-free survival, with median 13.2 months vs. 8.1 months (hazard ratio, 0.62; 95% confidence interval, 0.51-0.74; P < .0001). In the intention-to-treat population, which included the HER2 ultralow patients, the benefit was the same (HR, 0.63; 95% CI, 0.53-0.75; P < .0001). This suggested that T-DXd is also effective in these patients, and it will be extremely important going forward to identify the lowest level of HER2 expression in metastatic breast cancers that can still benefit from therapy with T-DxD, Dr. Curigliano said.

Overall survival could not be assessed in the study cohort because complete data were not yet available, Dr. Curigliano said. However, trends pointed to an advantage for T-DXd, and tumor response rates were markedly higher with T-DXd: 57% compared with 31% for standard chemotherapy in the full cohort.

Serious treatment-emergent adverse events were more common in the T-Dxd–treated patients, with 11% of that arm developing drug-related interstitial lung disease, and three patients dying of it. Five patients in the T-DXd arm died of adverse events deemed treatment-related, and none died from treatment-related adverse events in the standard chemotherapy arm. Altogether 11 patients died in the T-DXd arm and 6 in the chemotherapy arm.
 

Clinical Implications of DESTINY-Breast06

The DESTINY-Breast06 data show that “we have to again change how we think about HER2 expression. Even very low levels of HER2 expression matter, and they can be leveraged to improve the treatment for our patients,” said Ian Krop, MD, PhD, of the Yale Cancer Center in New Haven, Connecticut, during the session where the results were presented.

But T-DXd may not be an appropriate first choice for all patients, especially given the safety concerns associated with T-DXd, he continued. With overall survival and quality-of-life data still lacking, clinicians will have to determine on a case-by-case basis who should get T-DXd in the first line.

“For patients who have symptomatic metastatic disease, who need a response to address those symptoms, those in whom you think chemotherapy may not work as well because they had, for example, a short recurrence interval after their adjuvant chemotherapy — using T-DXd in that first-line setting makes perfect sense to take advantage of the substantially higher response rate compared to chemo,” Dr. Krop said. “But for patients who have asymptomatic low burdens of disease, it seems very reasonable to consider using a well-tolerated chemotherapy like capecitabine in the first line, and then using T-DXd in the second line.”

In an interview, Erica Mayer, MD, of the Dana Farber Cancer Institute in Boston, Massachusetts, said patient choice will also matter in determining whether T-DXd is a first-line option. The known toxicity of T-DXd was underscored by the latest findings, she noted, while capecitabine, one of the chemotherapy choices in the control arm of the study, “really reflects what the majority of breast cancer doctors tend to offer, both because of the efficacy of the drug, but also because it’s oral, it’s well tolerated, and you don’t lose your hair.”
 

DESTINY-Breast07 Results

The DESTINY-Breast07 findings, from a Phase 1B open-label trial measuring safety and tolerability, were presented by Fabrice Andre, MD, PhD, of Université Paris Saclay in Paris, France. Dr. Andre and his colleagues presented the first data comparing T-DXd monotherapy and T-DXd with pertuzumab — a monoclonal antibody targeting HER2 — as a first-line treatment in patients with HER2-overexpressing (immunohistochemistry 3 and above) metastatic breast cancer. (J Clin Oncol 42, 2024 [suppl 16; abstr 1009]).

Current first-line standard of care for these patients is pertuzumab, trastuzumab, and docetaxel, based on results from the 2015 CLEOPATRA trial. T-DXd is currently approved as a second-line treatment.

Dr. Andre and his colleagues randomized 75 patients to monotherapy with T-DXd and 50 to combined therapy, with a median follow-up of 2 years.

After 1 year of treatment, combination of T-DXd and pertuzumab was seen to be associated with a progression-free survival of 89% at 1 year (80% CI, 81.9-93.9), compared with 80% in patients treated with T-DXd alone (80% CI, 73.7-86.1). Objective tumor response rate was 84% for the combined therapy at 12 weeks, with 20% of patients seeing a complete response, compared with 76% and 8%, respectively, for monotherapy.

As in the DESTINY-Breast06 trial, adverse events were high, with interstitial lung disease seen in 9% of patients in the monotherapy group and in 14% of the combined-therapy patients, although no treatment-related deaths occurred.

A randomized phase 3 trial, DESTINY Breast09, will now compare the monotherapy and the combined therapy with standard care.

T-DXd has seen a rapidly expanding role in treating breast and other solid tumors. The DESTINY Breast06 findings will move up its place in the treatment algorithm for metastatic breast cancer, “allowing us to now offer T-DXd as the first chemotherapy choice for patients who are making that transition to chemotherapy over many of the traditional provider choices that we previously have offered,” Dr. Mayer said.

The results “support the use of not only this specific agent, but also the concept of antibody drug conjugates as a very effective way to treat malignancy,” she added.

Dr. Curigliano reported receiving speaker’s fees, research funding, and other support from AstraZeneca and Daiichi Sankyo, among other companies, as did most of his co-authors, of whom three were AstraZeneca employees. Dr. Fabrice disclosed receiving research funding, travel compensation, and/or advisory fees from AstraZeneca and other entities, as did several of his co-authors. Two of his co-authors were employed by AstraZeneca and Roche, manufacturers of the study drugs. Dr. Krop and Dr. Mayer disclosed relationships with AstraZeneca and others.

Premenopausal patients with hormone receptor positive and human epidermal growth factor receptor 2 negative invasive breast cancer were significantly more likely to respond to chemotherapy plus endocrine therapy if their baseline anti-Müllerian hormone levels were10 pg/mL or higher, a new analysis shows.

The new findings also show that women with low baseline anti-Müllerian hormone (AMH) of less than 10 pg/mL do not benefit from chemotherapy. In fact, AMH levels were a better predictor of chemotherapy benefit than self-reported premenopausal status, age, and other hormone levels.

“We may be overtreating some of our patients” with invasive breast cancer and low AMH levels, Kevin Kalinsky, MD, of the Winship Cancer Institute of Emory University, Atlanta, said in a presentation at the annual meeting of the American Society of Clinical Oncology (ASCO).

The potential implication of the study is that clinicians may be able to stop giving chemotherapy to a subset of breast cancer patients who will not benefit from it, he said in the presentation.
 

New Analysis Singles Out AMH Levels

In a new analysis of data from the RxPONDER trial, Dr. Kalinsky shared data from 1,016 patients who were younger than 55 years of age and self-reported as premenopausal.

The original RxPONDER trial (also known as SWOG S1007) was a randomized, phase 3 trial designed to evaluate the benefit of endocrine therapy (ET) alone vs. ET plus chemotherapy in patients with hormone receptor positive and human epidermal growth factor receptor 2 negative (HR+/HER2-) invasive breast cancer and low recurrence scores (25 or less with genomic testing by Oncotype DX), Dr. Kalinsky said in his presentation.

The researchers found no improvement in invasive disease-free survival (IDFS) with the addition of chemotherapy to ET overall, but significant IDFS improvement occurred with added chemotherapy to ET in the subgroup of self-reported premenopausal women (hazard ratio 0.60).

To better identify the impact of menopausal status on patients who would benefit or not benefit from chemotherapy in the new analysis, the researchers assessed baseline serum samples of serum estradiol, progesterone, follicular stimulating hormone(FSH), luteinizing hormone, AMH, and inhibin B.

The primary outcomes were associations of these markers (continuous and dichotomized) with IDFS and distant relapse-free survival with prognosis and prediction of chemotherapy benefit, based on Cox regression analysis.

Of the six markers analyzed, only AMH showed an association with chemotherapy benefits. “AMH is more stable and reliable during the menstrual cycle” compared to other hormones such as FSH and estradiol. Also, AMH levels ≥ 10 pg/mL are considered a standard cutoff to define normal ovarian reserve, Dr. Kalinsky said in his presentation.

A total of 209 patients (21%) had low AMH (less than 10 pg/mL) and were considered postmenopausal, and 806 (79%) were considered premenopausal, with AMH levels of 10 pg/mL or higher.

Chemotherapy plus ET was significantly more beneficial than ET alone in the premenopausal patients with AMH levels ≥ 10 pg/mL (hazard ratio 0.48), Dr. Kalinsky said. By contrast, no chemotherapy benefit was seen in the patients deemed postmenopausal, with low AMH levels (HR 1.21).

In the patients with AMH of 10 pg/mL or higher, the absolute 5-year IDFS benefit of chemotherapy was 7.8%, compared to no notable difference for those with low AMH levels.

Similarly, 5-year DRFS with chemotherapy in patients with AMH of 10 pg/mL or higher was 4.4% (HR 0.41), with no benefit for those with low AMH (HR 1.50).

The findings were limited by the post hoc design and lack of longitudinal data, Dr. Kalinsky said.

During the question-and-answer session, Dr. Kalinsky said that he hoped the data could be incorporated into a clinical model “to further refine patients who need chemotherapy or don’t.” The results suggest that the reproductive hormone AMH can be used to identify premenopausal women with HR+/HER2- invasive breast cancer and intermediate risk based on oncotype scores who would likely benefit from chemotherapy, while those with lower AMH who could forgo it, Dr. Kalinsky concluded.
 

AMH May Ultimately Inform Chemotherapy Choices

The findings are “thoughtful and intriguing” and may inform which patients benefit from adjuvant chemotherapy and which may not, said Lisa A. Carey, MD, of Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, who served as discussant for the abstract.

Dr. Carey noted as a caveat that AMH is not currently recommended by the American College of Obstetricians and Gynecologists for menopause prediction. However, AMH is “a very credible biomarker of ovarian reserve,” she said in her presentation.

As for clinical implications, the lack of chemotherapy benefit in patients with low AMH at baseline suggests that at least part of the benefits of chemotherapy come from ovarian suppression, Dr. Carey said.

Current assessments of menopausal status are often crude, she noted, and AMH may be helpful when menopausal status is clinically unclear.

Dr. Carey agreed the findings were limited by the post hoc design, and longitudinal data are needed. However, the clinical implications are real if the results are validated, she said, and longitudinal data will be explored in the currently enrolling NRG BR009 OFSET trial.
 

Clinical Challenges of Menopausal Status

Since the original RxPONDER showed a benefit of chemotherapy for premenopausal women, but not for postmenopausal women with the same low recurrence score, the medical oncology community has worked to determine how much of the benefit seen was related to the ovarian suppression associated with chemotherapy, Megan Kruse, MD, of the Cleveland Clinic, said in an interview.

“Determining a woman’s menopausal status can be challenging in the clinic, as many women have had hysterectomy but have intact ovaries or may have significantly irregular periods, which can lead to confusion about the best endocrine therapy to recommend and how to categorize risk when it comes to Oncotype DX testing,” said Dr. Kruse. She was not involved in the RxPONDER study, but commented on the study in a podcast for ASCO Daily News in advance of the ASCO meeting.

“I was surprised that only AMH showed an association with chemotherapy benefit, as we often obtain estradiol/FSH levels in clinic to try to help with the menopausal assessment,” Dr. Kruse said in an interview. However, in clinical practice, the data may help discuss systemic therapy in patients who are near clinical menopause and trying to decide whether the potential added benefit of chemotherapy is worth the associated toxicity, she said.

“My hope is that new data allow for a more informed, individualized decision-making process,” she added.

Potential barriers to incorporate AMH into chemotherapy decisions in clinical practice include the need for insurance coverage for AMH levels, Dr. Kruse said in an interview. “The [AMH] levels also can be dynamic, so checking one point in time and making such a significant clinical decision based on one level is also a bit concerning,” she said.

Looking ahead, Dr. Kruse emphasized the need to complete the NRG BR-009 OFSET trial. That trial is designed to answer the question of whether adjuvant chemotherapy added to ovarian suppression (OS) plus ET is superior to OS plus ET for premenopausal women with early stage high-risk node negative or 1-3 lymph nodes positive breast cancer with an RS score of 25 or lower, she said.

“This extra analysis of the RxPONDER trial helps to further understand how premenopausal women may best benefit from adjuvant treatments,” Malinda T. West, MD, of the University of Wisconsin, Madison, said in an interview. The new study is important because it shows the ability of serum AMH to help predict ovarian reserve and imminent menopause, said Dr. West, who was not involved in the study.

In clinical practice, the study provides further insight into how premenopausal women may benefit from added chemotherapy and the role of ovarian suppression, Dr. West said.

The study was supported by the Breast Cancer Research Foundation, the National Institutes of Health/National Institute of General Medical Sciences/National Cancer Institute, Exact Sciences Corporation (previously Genomic Health), and the Hope Foundation for Cancer Research.

Dr. Kalinsky disclosed that immediate family members are employed by EQRx and GRAIL, with stock or other ownership interests in these companies. He disclosed consulting or advisory roles with 4D Pharma, AstraZeneca, Cullinan Oncology, Daiichi Sankyo/AstraZeneca, eFFECTOR Therapeutics, Genentech/Roche, Immunomedics, Lilly, Menarini Silicon Biosystems, Merck, Mersana, Myovant Sciences, Novartis, Oncosec, Prelude Therapeutics, Puma Biotechnology, RayzeBio, Seagen, and Takeda. Dr. Kalinsky further disclosed research funding to his institution from Ascentage Pharma, AstraZeneca, Daiichi Sankyo, Genentech/Roche, Lilly, Novartis, and Seagen, and relationships with Genentech and Immunomedics.

Dr. Carey disclosed research funding to her institution from AstraZeneca, Genentech/Roche, Gilead Sciences, Lilly, NanoString Technologies, Novartis, Seagen, and Veracyte. She disclosed an uncompensated relationship with Seagen, and uncompensated relationships between her institution and Genentech/Roche, GlaxoSmithKline, Lilly, and Novartis.

Dr. Kruse disclosed consulting or advisory roles with Novartis Oncology, Puma Biotechnology, Immunomedics, Eisai, Seattle Genetics, and Lilly.

Dr. West had no financial conflicts to disclose.

Premenopausal patients with hormone receptor positive and human epidermal growth factor receptor 2 negative invasive breast cancer were significantly more likely to respond to chemotherapy plus endocrine therapy if their baseline anti-Müllerian hormone levels were10 pg/mL or higher, a new analysis shows.

The new findings also show that women with low baseline anti-Müllerian hormone (AMH) of less than 10 pg/mL do not benefit from chemotherapy. In fact, AMH levels were a better predictor of chemotherapy benefit than self-reported premenopausal status, age, and other hormone levels.

“We may be overtreating some of our patients” with invasive breast cancer and low AMH levels, Kevin Kalinsky, MD, of the Winship Cancer Institute of Emory University, Atlanta, said in a presentation at the annual meeting of the American Society of Clinical Oncology (ASCO).

The potential implication of the study is that clinicians may be able to stop giving chemotherapy to a subset of breast cancer patients who will not benefit from it, he said in the presentation.
 

New Analysis Singles Out AMH Levels

In a new analysis of data from the RxPONDER trial, Dr. Kalinsky shared data from 1,016 patients who were younger than 55 years of age and self-reported as premenopausal.

The original RxPONDER trial (also known as SWOG S1007) was a randomized, phase 3 trial designed to evaluate the benefit of endocrine therapy (ET) alone vs. ET plus chemotherapy in patients with hormone receptor positive and human epidermal growth factor receptor 2 negative (HR+/HER2-) invasive breast cancer and low recurrence scores (25 or less with genomic testing by Oncotype DX), Dr. Kalinsky said in his presentation.

The researchers found no improvement in invasive disease-free survival (IDFS) with the addition of chemotherapy to ET overall, but significant IDFS improvement occurred with added chemotherapy to ET in the subgroup of self-reported premenopausal women (hazard ratio 0.60).

To better identify the impact of menopausal status on patients who would benefit or not benefit from chemotherapy in the new analysis, the researchers assessed baseline serum samples of serum estradiol, progesterone, follicular stimulating hormone(FSH), luteinizing hormone, AMH, and inhibin B.

The primary outcomes were associations of these markers (continuous and dichotomized) with IDFS and distant relapse-free survival with prognosis and prediction of chemotherapy benefit, based on Cox regression analysis.

Of the six markers analyzed, only AMH showed an association with chemotherapy benefits. “AMH is more stable and reliable during the menstrual cycle” compared to other hormones such as FSH and estradiol. Also, AMH levels ≥ 10 pg/mL are considered a standard cutoff to define normal ovarian reserve, Dr. Kalinsky said in his presentation.

A total of 209 patients (21%) had low AMH (less than 10 pg/mL) and were considered postmenopausal, and 806 (79%) were considered premenopausal, with AMH levels of 10 pg/mL or higher.

Chemotherapy plus ET was significantly more beneficial than ET alone in the premenopausal patients with AMH levels ≥ 10 pg/mL (hazard ratio 0.48), Dr. Kalinsky said. By contrast, no chemotherapy benefit was seen in the patients deemed postmenopausal, with low AMH levels (HR 1.21).

In the patients with AMH of 10 pg/mL or higher, the absolute 5-year IDFS benefit of chemotherapy was 7.8%, compared to no notable difference for those with low AMH levels.

Similarly, 5-year DRFS with chemotherapy in patients with AMH of 10 pg/mL or higher was 4.4% (HR 0.41), with no benefit for those with low AMH (HR 1.50).

The findings were limited by the post hoc design and lack of longitudinal data, Dr. Kalinsky said.

During the question-and-answer session, Dr. Kalinsky said that he hoped the data could be incorporated into a clinical model “to further refine patients who need chemotherapy or don’t.” The results suggest that the reproductive hormone AMH can be used to identify premenopausal women with HR+/HER2- invasive breast cancer and intermediate risk based on oncotype scores who would likely benefit from chemotherapy, while those with lower AMH who could forgo it, Dr. Kalinsky concluded.
 

AMH May Ultimately Inform Chemotherapy Choices

The findings are “thoughtful and intriguing” and may inform which patients benefit from adjuvant chemotherapy and which may not, said Lisa A. Carey, MD, of Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, who served as discussant for the abstract.

Dr. Carey noted as a caveat that AMH is not currently recommended by the American College of Obstetricians and Gynecologists for menopause prediction. However, AMH is “a very credible biomarker of ovarian reserve,” she said in her presentation.

As for clinical implications, the lack of chemotherapy benefit in patients with low AMH at baseline suggests that at least part of the benefits of chemotherapy come from ovarian suppression, Dr. Carey said.

Current assessments of menopausal status are often crude, she noted, and AMH may be helpful when menopausal status is clinically unclear.

Dr. Carey agreed the findings were limited by the post hoc design, and longitudinal data are needed. However, the clinical implications are real if the results are validated, she said, and longitudinal data will be explored in the currently enrolling NRG BR009 OFSET trial.
 

Clinical Challenges of Menopausal Status

Since the original RxPONDER showed a benefit of chemotherapy for premenopausal women, but not for postmenopausal women with the same low recurrence score, the medical oncology community has worked to determine how much of the benefit seen was related to the ovarian suppression associated with chemotherapy, Megan Kruse, MD, of the Cleveland Clinic, said in an interview.

“Determining a woman’s menopausal status can be challenging in the clinic, as many women have had hysterectomy but have intact ovaries or may have significantly irregular periods, which can lead to confusion about the best endocrine therapy to recommend and how to categorize risk when it comes to Oncotype DX testing,” said Dr. Kruse. She was not involved in the RxPONDER study, but commented on the study in a podcast for ASCO Daily News in advance of the ASCO meeting.

“I was surprised that only AMH showed an association with chemotherapy benefit, as we often obtain estradiol/FSH levels in clinic to try to help with the menopausal assessment,” Dr. Kruse said in an interview. However, in clinical practice, the data may help discuss systemic therapy in patients who are near clinical menopause and trying to decide whether the potential added benefit of chemotherapy is worth the associated toxicity, she said.

“My hope is that new data allow for a more informed, individualized decision-making process,” she added.

Potential barriers to incorporate AMH into chemotherapy decisions in clinical practice include the need for insurance coverage for AMH levels, Dr. Kruse said in an interview. “The [AMH] levels also can be dynamic, so checking one point in time and making such a significant clinical decision based on one level is also a bit concerning,” she said.

Looking ahead, Dr. Kruse emphasized the need to complete the NRG BR-009 OFSET trial. That trial is designed to answer the question of whether adjuvant chemotherapy added to ovarian suppression (OS) plus ET is superior to OS plus ET for premenopausal women with early stage high-risk node negative or 1-3 lymph nodes positive breast cancer with an RS score of 25 or lower, she said.

“This extra analysis of the RxPONDER trial helps to further understand how premenopausal women may best benefit from adjuvant treatments,” Malinda T. West, MD, of the University of Wisconsin, Madison, said in an interview. The new study is important because it shows the ability of serum AMH to help predict ovarian reserve and imminent menopause, said Dr. West, who was not involved in the study.

In clinical practice, the study provides further insight into how premenopausal women may benefit from added chemotherapy and the role of ovarian suppression, Dr. West said.

The study was supported by the Breast Cancer Research Foundation, the National Institutes of Health/National Institute of General Medical Sciences/National Cancer Institute, Exact Sciences Corporation (previously Genomic Health), and the Hope Foundation for Cancer Research.

Dr. Kalinsky disclosed that immediate family members are employed by EQRx and GRAIL, with stock or other ownership interests in these companies. He disclosed consulting or advisory roles with 4D Pharma, AstraZeneca, Cullinan Oncology, Daiichi Sankyo/AstraZeneca, eFFECTOR Therapeutics, Genentech/Roche, Immunomedics, Lilly, Menarini Silicon Biosystems, Merck, Mersana, Myovant Sciences, Novartis, Oncosec, Prelude Therapeutics, Puma Biotechnology, RayzeBio, Seagen, and Takeda. Dr. Kalinsky further disclosed research funding to his institution from Ascentage Pharma, AstraZeneca, Daiichi Sankyo, Genentech/Roche, Lilly, Novartis, and Seagen, and relationships with Genentech and Immunomedics.

Dr. Carey disclosed research funding to her institution from AstraZeneca, Genentech/Roche, Gilead Sciences, Lilly, NanoString Technologies, Novartis, Seagen, and Veracyte. She disclosed an uncompensated relationship with Seagen, and uncompensated relationships between her institution and Genentech/Roche, GlaxoSmithKline, Lilly, and Novartis.

Dr. Kruse disclosed consulting or advisory roles with Novartis Oncology, Puma Biotechnology, Immunomedics, Eisai, Seattle Genetics, and Lilly.

Dr. West had no financial conflicts to disclose.

Premenopausal patients with hormone receptor positive and human epidermal growth factor receptor 2 negative invasive breast cancer were significantly more likely to respond to chemotherapy plus endocrine therapy if their baseline anti-Müllerian hormone levels were10 pg/mL or higher, a new analysis shows.

The new findings also show that women with low baseline anti-Müllerian hormone (AMH) of less than 10 pg/mL do not benefit from chemotherapy. In fact, AMH levels were a better predictor of chemotherapy benefit than self-reported premenopausal status, age, and other hormone levels.

“We may be overtreating some of our patients” with invasive breast cancer and low AMH levels, Kevin Kalinsky, MD, of the Winship Cancer Institute of Emory University, Atlanta, said in a presentation at the annual meeting of the American Society of Clinical Oncology (ASCO).

The potential implication of the study is that clinicians may be able to stop giving chemotherapy to a subset of breast cancer patients who will not benefit from it, he said in the presentation.
 

New Analysis Singles Out AMH Levels

In a new analysis of data from the RxPONDER trial, Dr. Kalinsky shared data from 1,016 patients who were younger than 55 years of age and self-reported as premenopausal.

The original RxPONDER trial (also known as SWOG S1007) was a randomized, phase 3 trial designed to evaluate the benefit of endocrine therapy (ET) alone vs. ET plus chemotherapy in patients with hormone receptor positive and human epidermal growth factor receptor 2 negative (HR+/HER2-) invasive breast cancer and low recurrence scores (25 or less with genomic testing by Oncotype DX), Dr. Kalinsky said in his presentation.

The researchers found no improvement in invasive disease-free survival (IDFS) with the addition of chemotherapy to ET overall, but significant IDFS improvement occurred with added chemotherapy to ET in the subgroup of self-reported premenopausal women (hazard ratio 0.60).

To better identify the impact of menopausal status on patients who would benefit or not benefit from chemotherapy in the new analysis, the researchers assessed baseline serum samples of serum estradiol, progesterone, follicular stimulating hormone(FSH), luteinizing hormone, AMH, and inhibin B.

The primary outcomes were associations of these markers (continuous and dichotomized) with IDFS and distant relapse-free survival with prognosis and prediction of chemotherapy benefit, based on Cox regression analysis.

Of the six markers analyzed, only AMH showed an association with chemotherapy benefits. “AMH is more stable and reliable during the menstrual cycle” compared to other hormones such as FSH and estradiol. Also, AMH levels ≥ 10 pg/mL are considered a standard cutoff to define normal ovarian reserve, Dr. Kalinsky said in his presentation.

A total of 209 patients (21%) had low AMH (less than 10 pg/mL) and were considered postmenopausal, and 806 (79%) were considered premenopausal, with AMH levels of 10 pg/mL or higher.

Chemotherapy plus ET was significantly more beneficial than ET alone in the premenopausal patients with AMH levels ≥ 10 pg/mL (hazard ratio 0.48), Dr. Kalinsky said. By contrast, no chemotherapy benefit was seen in the patients deemed postmenopausal, with low AMH levels (HR 1.21).

In the patients with AMH of 10 pg/mL or higher, the absolute 5-year IDFS benefit of chemotherapy was 7.8%, compared to no notable difference for those with low AMH levels.

Similarly, 5-year DRFS with chemotherapy in patients with AMH of 10 pg/mL or higher was 4.4% (HR 0.41), with no benefit for those with low AMH (HR 1.50).

The findings were limited by the post hoc design and lack of longitudinal data, Dr. Kalinsky said.

During the question-and-answer session, Dr. Kalinsky said that he hoped the data could be incorporated into a clinical model “to further refine patients who need chemotherapy or don’t.” The results suggest that the reproductive hormone AMH can be used to identify premenopausal women with HR+/HER2- invasive breast cancer and intermediate risk based on oncotype scores who would likely benefit from chemotherapy, while those with lower AMH who could forgo it, Dr. Kalinsky concluded.
 

AMH May Ultimately Inform Chemotherapy Choices

The findings are “thoughtful and intriguing” and may inform which patients benefit from adjuvant chemotherapy and which may not, said Lisa A. Carey, MD, of Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, who served as discussant for the abstract.

Dr. Carey noted as a caveat that AMH is not currently recommended by the American College of Obstetricians and Gynecologists for menopause prediction. However, AMH is “a very credible biomarker of ovarian reserve,” she said in her presentation.

As for clinical implications, the lack of chemotherapy benefit in patients with low AMH at baseline suggests that at least part of the benefits of chemotherapy come from ovarian suppression, Dr. Carey said.

Current assessments of menopausal status are often crude, she noted, and AMH may be helpful when menopausal status is clinically unclear.

Dr. Carey agreed the findings were limited by the post hoc design, and longitudinal data are needed. However, the clinical implications are real if the results are validated, she said, and longitudinal data will be explored in the currently enrolling NRG BR009 OFSET trial.
 

Clinical Challenges of Menopausal Status

Since the original RxPONDER showed a benefit of chemotherapy for premenopausal women, but not for postmenopausal women with the same low recurrence score, the medical oncology community has worked to determine how much of the benefit seen was related to the ovarian suppression associated with chemotherapy, Megan Kruse, MD, of the Cleveland Clinic, said in an interview.

“Determining a woman’s menopausal status can be challenging in the clinic, as many women have had hysterectomy but have intact ovaries or may have significantly irregular periods, which can lead to confusion about the best endocrine therapy to recommend and how to categorize risk when it comes to Oncotype DX testing,” said Dr. Kruse. She was not involved in the RxPONDER study, but commented on the study in a podcast for ASCO Daily News in advance of the ASCO meeting.

“I was surprised that only AMH showed an association with chemotherapy benefit, as we often obtain estradiol/FSH levels in clinic to try to help with the menopausal assessment,” Dr. Kruse said in an interview. However, in clinical practice, the data may help discuss systemic therapy in patients who are near clinical menopause and trying to decide whether the potential added benefit of chemotherapy is worth the associated toxicity, she said.

“My hope is that new data allow for a more informed, individualized decision-making process,” she added.

Potential barriers to incorporate AMH into chemotherapy decisions in clinical practice include the need for insurance coverage for AMH levels, Dr. Kruse said in an interview. “The [AMH] levels also can be dynamic, so checking one point in time and making such a significant clinical decision based on one level is also a bit concerning,” she said.

Looking ahead, Dr. Kruse emphasized the need to complete the NRG BR-009 OFSET trial. That trial is designed to answer the question of whether adjuvant chemotherapy added to ovarian suppression (OS) plus ET is superior to OS plus ET for premenopausal women with early stage high-risk node negative or 1-3 lymph nodes positive breast cancer with an RS score of 25 or lower, she said.

“This extra analysis of the RxPONDER trial helps to further understand how premenopausal women may best benefit from adjuvant treatments,” Malinda T. West, MD, of the University of Wisconsin, Madison, said in an interview. The new study is important because it shows the ability of serum AMH to help predict ovarian reserve and imminent menopause, said Dr. West, who was not involved in the study.

In clinical practice, the study provides further insight into how premenopausal women may benefit from added chemotherapy and the role of ovarian suppression, Dr. West said.

The study was supported by the Breast Cancer Research Foundation, the National Institutes of Health/National Institute of General Medical Sciences/National Cancer Institute, Exact Sciences Corporation (previously Genomic Health), and the Hope Foundation for Cancer Research.

Dr. Kalinsky disclosed that immediate family members are employed by EQRx and GRAIL, with stock or other ownership interests in these companies. He disclosed consulting or advisory roles with 4D Pharma, AstraZeneca, Cullinan Oncology, Daiichi Sankyo/AstraZeneca, eFFECTOR Therapeutics, Genentech/Roche, Immunomedics, Lilly, Menarini Silicon Biosystems, Merck, Mersana, Myovant Sciences, Novartis, Oncosec, Prelude Therapeutics, Puma Biotechnology, RayzeBio, Seagen, and Takeda. Dr. Kalinsky further disclosed research funding to his institution from Ascentage Pharma, AstraZeneca, Daiichi Sankyo, Genentech/Roche, Lilly, Novartis, and Seagen, and relationships with Genentech and Immunomedics.

Dr. Carey disclosed research funding to her institution from AstraZeneca, Genentech/Roche, Gilead Sciences, Lilly, NanoString Technologies, Novartis, Seagen, and Veracyte. She disclosed an uncompensated relationship with Seagen, and uncompensated relationships between her institution and Genentech/Roche, GlaxoSmithKline, Lilly, and Novartis.

Dr. Kruse disclosed consulting or advisory roles with Novartis Oncology, Puma Biotechnology, Immunomedics, Eisai, Seattle Genetics, and Lilly.

Dr. West had no financial conflicts to disclose.

For women with early-stage estrogen-receptor positive breast cancer, adjuvant endocrine therapy is known to decrease the likelihood of recurrence and improve survival, while omitting the therapy is associated with a higher risk of death.

For that reason, current guidelines, including those from the National Comprehensive Cancer Network, recommend adjuvant endocrine therapy (AET) for patients with estrogen-receptor positive (ER+) breast cancers.

But these and other guidelines do not make recommendations for a class of tumors deemed estrogen receptor low positive, often referred to as “ER-low,” a category in which ER is seen expressed in between 1% and 10% of cells. This is because benefits of endocrine therapy have not been demonstrated in patients with ER-low disease.

New research presented at the annual meeting of the American Society of Clinical Oncology in Chicago may change how clinicians and patients think about endocrine therapy. The findings showed that omitting endocrine therapy after surgery and chemotherapy was associated with a 25% higher chance of death within 3 years in ER-low patients.

Endocrine therapy, the investigators say, should therefore be offered to all patients with ER-low cancers, at least until it can be determined which subgroups are most likely to benefit.

How Was the Study Conducted?

Grace M. Choong, MD, of the Mayo Clinic in Rochester, Minnesota, and her colleagues, looked at 2018-2020 data from the National Cancer Database for more than 350,000 female patients with stages 1-3, ER+ breast cancer. From among these they identified about 7000 patients with ER-low cancers who had undergone adjuvant or neoadjuvant chemotherapy.

“We specifically wanted to focus on those treated with chemotherapy as these patients have a higher risk of recurrence in our short interval follow-up,” Dr. Choong said during her presentation.

Patients’ median age was 55 years, and three-quarters of them were White. Their tumors were more likely to be HER2-negative (65%), PR-negative (73%), have higher Ki-67 expression, and have a higher clinical stage (73% grade III).

Forty-two percent of patients did not undergo AET as part of their treatment regimen, with various tumor factors seen associated with AET omission. At a median 3 years of follow-up, 586 patients had died. After the researchers controlled for age, comorbidities, year of diagnosis, tumor factors, and pathologic stage, the effect of omitting AET still resulted in significantly worse survival: (HR 1.25, 95% CI: 1.05-1.48, P = .01).

Mortality was driven by patients with residual disease after neoadjuvant chemotherapy, who comprised nearly half the study cohort. In these patients, omission of endocrine therapy was associated with a 27% higher risk of death (HR 1.27, 1.10-1.58). However, for those with a complete pathological response following chemotherapy, omission of endocrine therapy was not associated with a higher risk of death (HR 1.06; 0.62-1.80).

The investigators noted several limitations of their study, including a retrospective design and no information available on recurrence or the duration of endocrine therapy.
 

Why Is Endocrine Therapy So Frequently Omitted in This Patient Group?

Matthew P. Goetz, MD, of the Mayo Clinic, the study’s corresponding author, said in an interview that in Sweden, for example, ER-low patients are explicitly not offered endocrine therapy based on Swedish guidelines.

In other settings, he said, it is unclear what is happening.

“Are patients refusing it? Do physicians not even offer it because they think there is no value? We do not have that granular detail, but our data right now suggests a physician should be having this conversation with patients,” he said.
 

Which ER-Low Patients Are Likely To Benefit?

The findings apply mostly to patients with residual disease after chemotherapy, and underlying biological factors are likely the reason, Dr. Goetz said.

ER-low patients are a heterogeneous group, he explained.

“In genomic profiling, where we look at the underlying biology of these cancers, most of the ER-low cancers are considered the basal subtype of triple negative breast cancer. Those patients should have absolutely zero benefit from endocrine therapy. But there is another group, referred to as the luminal group, which comprises anywhere from 20% to 30% of the ER-low patients.”

Dr. Goetz said he expects to find that this latter group are the patients benefiting from endocrine therapy when they have residual disease.

“We are not yet at the point of saying to patients, ‘you have residual disease after chemotherapy. Let’s check your tumor to see if it is the basal or luminal subtype.’ But that is something that we are planning to look into. What is most important right now is that clinicians be aware of these data, and that there is a suggestion that omitting endocrine therapy may have detrimental effects on survival in this subgroup of patients.”
 

Are the Findings Compelling Enough To Change Clinical Practice Right Away?

In an interview about the findings, Eric Winer, MD, of the Yale Cancer Center in New Haven, Connecticut, cautioned that due to the retrospective study design, “we don’t know how doctors made decisions about who got endocrine therapy and who didn’t.”

The patients with the worst tumors tended not to get endocrine therapy, Dr. Winer noted, and despite attempts to adjust for this, “in any large data set like this, unlike in a randomized trial, you just can’t control for all the bias.”
 

What Should Doctors Tell Patients?

“In the setting of significant side effects from endocrine therapy, we’re still less certain about the benefits of endocrine therapy here than in somebody with an ER-high tumor,” Dr. Winer cautioned.

Nonetheless, he said, the new findings certainly suggest that there may be a benefit for endocrine therapy in patients with ER-low tumors, and doctors should make this known to patients. “It may not be the strongest evidence, but it’s evidence,” he said. “This is very much a question to be raised between the doctor and the patient.”

Dr. Choong and colleagues’ study was funded by a Mayo Clinic Breast Cancer SPORE grant. Dr. Goetz reported consulting fees and research support from pharmaceutical manufacturers, including AstraZeneca, Pfizer, Lilly, and Novartis. Dr. Choong and Dr. Winer reported no financial conflicts of interest.

For women with early-stage estrogen-receptor positive breast cancer, adjuvant endocrine therapy is known to decrease the likelihood of recurrence and improve survival, while omitting the therapy is associated with a higher risk of death.

For that reason, current guidelines, including those from the National Comprehensive Cancer Network, recommend adjuvant endocrine therapy (AET) for patients with estrogen-receptor positive (ER+) breast cancers.

But these and other guidelines do not make recommendations for a class of tumors deemed estrogen receptor low positive, often referred to as “ER-low,” a category in which ER is seen expressed in between 1% and 10% of cells. This is because benefits of endocrine therapy have not been demonstrated in patients with ER-low disease.

New research presented at the annual meeting of the American Society of Clinical Oncology in Chicago may change how clinicians and patients think about endocrine therapy. The findings showed that omitting endocrine therapy after surgery and chemotherapy was associated with a 25% higher chance of death within 3 years in ER-low patients.

Endocrine therapy, the investigators say, should therefore be offered to all patients with ER-low cancers, at least until it can be determined which subgroups are most likely to benefit.

How Was the Study Conducted?

Grace M. Choong, MD, of the Mayo Clinic in Rochester, Minnesota, and her colleagues, looked at 2018-2020 data from the National Cancer Database for more than 350,000 female patients with stages 1-3, ER+ breast cancer. From among these they identified about 7000 patients with ER-low cancers who had undergone adjuvant or neoadjuvant chemotherapy.

“We specifically wanted to focus on those treated with chemotherapy as these patients have a higher risk of recurrence in our short interval follow-up,” Dr. Choong said during her presentation.

Patients’ median age was 55 years, and three-quarters of them were White. Their tumors were more likely to be HER2-negative (65%), PR-negative (73%), have higher Ki-67 expression, and have a higher clinical stage (73% grade III).

Forty-two percent of patients did not undergo AET as part of their treatment regimen, with various tumor factors seen associated with AET omission. At a median 3 years of follow-up, 586 patients had died. After the researchers controlled for age, comorbidities, year of diagnosis, tumor factors, and pathologic stage, the effect of omitting AET still resulted in significantly worse survival: (HR 1.25, 95% CI: 1.05-1.48, P = .01).

Mortality was driven by patients with residual disease after neoadjuvant chemotherapy, who comprised nearly half the study cohort. In these patients, omission of endocrine therapy was associated with a 27% higher risk of death (HR 1.27, 1.10-1.58). However, for those with a complete pathological response following chemotherapy, omission of endocrine therapy was not associated with a higher risk of death (HR 1.06; 0.62-1.80).

The investigators noted several limitations of their study, including a retrospective design and no information available on recurrence or the duration of endocrine therapy.
 

Why Is Endocrine Therapy So Frequently Omitted in This Patient Group?

Matthew P. Goetz, MD, of the Mayo Clinic, the study’s corresponding author, said in an interview that in Sweden, for example, ER-low patients are explicitly not offered endocrine therapy based on Swedish guidelines.

In other settings, he said, it is unclear what is happening.

“Are patients refusing it? Do physicians not even offer it because they think there is no value? We do not have that granular detail, but our data right now suggests a physician should be having this conversation with patients,” he said.
 

Which ER-Low Patients Are Likely To Benefit?

The findings apply mostly to patients with residual disease after chemotherapy, and underlying biological factors are likely the reason, Dr. Goetz said.

ER-low patients are a heterogeneous group, he explained.

“In genomic profiling, where we look at the underlying biology of these cancers, most of the ER-low cancers are considered the basal subtype of triple negative breast cancer. Those patients should have absolutely zero benefit from endocrine therapy. But there is another group, referred to as the luminal group, which comprises anywhere from 20% to 30% of the ER-low patients.”

Dr. Goetz said he expects to find that this latter group are the patients benefiting from endocrine therapy when they have residual disease.

“We are not yet at the point of saying to patients, ‘you have residual disease after chemotherapy. Let’s check your tumor to see if it is the basal or luminal subtype.’ But that is something that we are planning to look into. What is most important right now is that clinicians be aware of these data, and that there is a suggestion that omitting endocrine therapy may have detrimental effects on survival in this subgroup of patients.”
 

Are the Findings Compelling Enough To Change Clinical Practice Right Away?

In an interview about the findings, Eric Winer, MD, of the Yale Cancer Center in New Haven, Connecticut, cautioned that due to the retrospective study design, “we don’t know how doctors made decisions about who got endocrine therapy and who didn’t.”

The patients with the worst tumors tended not to get endocrine therapy, Dr. Winer noted, and despite attempts to adjust for this, “in any large data set like this, unlike in a randomized trial, you just can’t control for all the bias.”
 

What Should Doctors Tell Patients?

“In the setting of significant side effects from endocrine therapy, we’re still less certain about the benefits of endocrine therapy here than in somebody with an ER-high tumor,” Dr. Winer cautioned.

Nonetheless, he said, the new findings certainly suggest that there may be a benefit for endocrine therapy in patients with ER-low tumors, and doctors should make this known to patients. “It may not be the strongest evidence, but it’s evidence,” he said. “This is very much a question to be raised between the doctor and the patient.”

Dr. Choong and colleagues’ study was funded by a Mayo Clinic Breast Cancer SPORE grant. Dr. Goetz reported consulting fees and research support from pharmaceutical manufacturers, including AstraZeneca, Pfizer, Lilly, and Novartis. Dr. Choong and Dr. Winer reported no financial conflicts of interest.

For women with early-stage estrogen-receptor positive breast cancer, adjuvant endocrine therapy is known to decrease the likelihood of recurrence and improve survival, while omitting the therapy is associated with a higher risk of death.

For that reason, current guidelines, including those from the National Comprehensive Cancer Network, recommend adjuvant endocrine therapy (AET) for patients with estrogen-receptor positive (ER+) breast cancers.

But these and other guidelines do not make recommendations for a class of tumors deemed estrogen receptor low positive, often referred to as “ER-low,” a category in which ER is seen expressed in between 1% and 10% of cells. This is because benefits of endocrine therapy have not been demonstrated in patients with ER-low disease.

New research presented at the annual meeting of the American Society of Clinical Oncology in Chicago may change how clinicians and patients think about endocrine therapy. The findings showed that omitting endocrine therapy after surgery and chemotherapy was associated with a 25% higher chance of death within 3 years in ER-low patients.

Endocrine therapy, the investigators say, should therefore be offered to all patients with ER-low cancers, at least until it can be determined which subgroups are most likely to benefit.

How Was the Study Conducted?

Grace M. Choong, MD, of the Mayo Clinic in Rochester, Minnesota, and her colleagues, looked at 2018-2020 data from the National Cancer Database for more than 350,000 female patients with stages 1-3, ER+ breast cancer. From among these they identified about 7000 patients with ER-low cancers who had undergone adjuvant or neoadjuvant chemotherapy.

“We specifically wanted to focus on those treated with chemotherapy as these patients have a higher risk of recurrence in our short interval follow-up,” Dr. Choong said during her presentation.

Patients’ median age was 55 years, and three-quarters of them were White. Their tumors were more likely to be HER2-negative (65%), PR-negative (73%), have higher Ki-67 expression, and have a higher clinical stage (73% grade III).

Forty-two percent of patients did not undergo AET as part of their treatment regimen, with various tumor factors seen associated with AET omission. At a median 3 years of follow-up, 586 patients had died. After the researchers controlled for age, comorbidities, year of diagnosis, tumor factors, and pathologic stage, the effect of omitting AET still resulted in significantly worse survival: (HR 1.25, 95% CI: 1.05-1.48, P = .01).

Mortality was driven by patients with residual disease after neoadjuvant chemotherapy, who comprised nearly half the study cohort. In these patients, omission of endocrine therapy was associated with a 27% higher risk of death (HR 1.27, 1.10-1.58). However, for those with a complete pathological response following chemotherapy, omission of endocrine therapy was not associated with a higher risk of death (HR 1.06; 0.62-1.80).

The investigators noted several limitations of their study, including a retrospective design and no information available on recurrence or the duration of endocrine therapy.
 

Why Is Endocrine Therapy So Frequently Omitted in This Patient Group?

Matthew P. Goetz, MD, of the Mayo Clinic, the study’s corresponding author, said in an interview that in Sweden, for example, ER-low patients are explicitly not offered endocrine therapy based on Swedish guidelines.

In other settings, he said, it is unclear what is happening.

“Are patients refusing it? Do physicians not even offer it because they think there is no value? We do not have that granular detail, but our data right now suggests a physician should be having this conversation with patients,” he said.
 

Which ER-Low Patients Are Likely To Benefit?

The findings apply mostly to patients with residual disease after chemotherapy, and underlying biological factors are likely the reason, Dr. Goetz said.

ER-low patients are a heterogeneous group, he explained.

“In genomic profiling, where we look at the underlying biology of these cancers, most of the ER-low cancers are considered the basal subtype of triple negative breast cancer. Those patients should have absolutely zero benefit from endocrine therapy. But there is another group, referred to as the luminal group, which comprises anywhere from 20% to 30% of the ER-low patients.”

Dr. Goetz said he expects to find that this latter group are the patients benefiting from endocrine therapy when they have residual disease.

“We are not yet at the point of saying to patients, ‘you have residual disease after chemotherapy. Let’s check your tumor to see if it is the basal or luminal subtype.’ But that is something that we are planning to look into. What is most important right now is that clinicians be aware of these data, and that there is a suggestion that omitting endocrine therapy may have detrimental effects on survival in this subgroup of patients.”
 

Are the Findings Compelling Enough To Change Clinical Practice Right Away?

In an interview about the findings, Eric Winer, MD, of the Yale Cancer Center in New Haven, Connecticut, cautioned that due to the retrospective study design, “we don’t know how doctors made decisions about who got endocrine therapy and who didn’t.”

The patients with the worst tumors tended not to get endocrine therapy, Dr. Winer noted, and despite attempts to adjust for this, “in any large data set like this, unlike in a randomized trial, you just can’t control for all the bias.”
 

What Should Doctors Tell Patients?

“In the setting of significant side effects from endocrine therapy, we’re still less certain about the benefits of endocrine therapy here than in somebody with an ER-high tumor,” Dr. Winer cautioned.

Nonetheless, he said, the new findings certainly suggest that there may be a benefit for endocrine therapy in patients with ER-low tumors, and doctors should make this known to patients. “It may not be the strongest evidence, but it’s evidence,” he said. “This is very much a question to be raised between the doctor and the patient.”

Dr. Choong and colleagues’ study was funded by a Mayo Clinic Breast Cancer SPORE grant. Dr. Goetz reported consulting fees and research support from pharmaceutical manufacturers, including AstraZeneca, Pfizer, Lilly, and Novartis. Dr. Choong and Dr. Winer reported no financial conflicts of interest.

Almost sixty percent of patients with macroscopic stage III melanoma who were randomized to 6 weeks of neoadjuvant immunotherapy needed no further treatment after therapeutic lymph node dissection in the phase 3 NADINA trial.

These results set a new standard of care in this patient population, the study’s lead author, Christian U. Blank, MD, PhD, reported at the annual meeting of the American Society of Clinical Oncology in Chicago.

Dr. Blank, a hematologist/oncologist from the Netherlands Cancer Institute in Amsterdam, called the result “very special,” noting that the trial included an active comparator, rather than a placebo control.

“When we treat these patients with surgery only, the outcome … is very bad: The 5-year relapse-free survival is only 30% and the overall survival is only 50%. Adjuvant therapy improves relapse-free survival but not overall survival ...Thus, there is an urgent need for these patients for novel therapy approaches,” he said during a press conference at the meeting.
 

Study Methods and Results

The study included 423 patients with stage III de novo or recurrent pathologically proven resectable melanoma with at least 1 lymph node metastasis. Patients were randomized to either the experimental neoadjuvant arm (n = 212), or the standard treatment control arm (n = 211), which consisted of therapeutic lymph node dissection (TLND) followed by 12 cycles of adjuvant nivolumab (NIVO 480 mg every 4 weeks).

Patients in the experimental arm received two cycles of neoadjuvant ipilimumab (IPI 80 mg every 3 weeks) plus NIVO 240 mg for 3 weeks followed by TLND. Those with a major pathologic response (MPR), defined as less than 10% vital tumor cells in the post-neoadjuvant resection specimen, went straight to follow-up.

Those without an MPR received adjuvant therapy. For patients with BRAF wild-type, this involved 11 cycles of adjuvant NIVO (480 mg every 4 weeks), while BRAF-mutated patients received dabrafenib plus trametinib (150 mg b.i.d./2 mg once a day; 46 weeks).

The study met its primary endpoint — event-free survival (EFS) — at the first interim analysis. After a median follow-up of 9.9 months, the estimated EFS was 83.7% for neoadjuvant immunotherapy versus 57.2% for standard of care, (P less than .0001, hazard ratio [HR] = 0.32).

“When we look into the subgroups, for example BRAF-mutated status or BRAF-wild-type status ... you see for both groups also a highly statistically significant outcome favoring the neoadjuvant therapy with hazard ratios of 0.29 and 0.35,” said Dr. Blank.

In total, 59% of patients in the experimental arm had an MPR needing no further treatment. “This is important, because the patients that achieve a major pathologic response have excellent outcomes, with an EFS of 95%,” said Dr. Blank.

He added that those with a partial response had an EFS of 76%, and among those who had “nonresponse,” the EFS was 57% — the same as that of patients in the control arm.

Toxicities were considered transient and acceptable, with systemic treatment-related grade 3 or 4 events in 29.7% of the neoadjuvant arm and 14.7% of the adjuvant arm.

NADINA is the first neoadjuvant checkpoint inhibitor phase 3 study in melanoma and the first phase 3 trial in oncology testing a checkpoint inhibitor without chemotherapy, noted Dr. Blank.

“At the moment we see only additions of immunotherapy to the chemotherapy neoadjuvant arms, but here you see that we can also treat patients with pure immunotherapy.”
 

Neoadjuvant Therapy Defined as Standard of Care

When considered along with evidence from the phase 2 SWOG 1801 study (N Engl J Med. 2023;388:813-8), “NADINA defines neoadjuvant therapy as the new standard of care for macroscopic stage III melanoma “which means that all trials currently ongoing need to be amended from adjuvant comparators to neoadjuvant comparators,” he said.

Dr. Blank called the trial a “new template for other malignancies implementing a neoadjuvant immunotherapy regimen followed by a response-driven adjuvant therapy.

“I think we see at the moment only sandwich designs, and this is more sales driven than patient driven, because what we have seen is that if a patient achieves a really deep response, the patient doesn’t need an adjuvant part,” he said.

Commenting during the press conference, Michael Lowe, MD, said the result “confirms and shows for the first time in a phase 3 study that giving immunotherapy before surgery results in superior outcomes to giving immunotherapy only after surgery.”

Dr. Lowe, associate professor in the Division of Surgical Oncology, at Emory University School of Medicine, Atlanta, added that the study “also confirms that giving two immunotherapy drugs before surgery results in excellent responses.”

However, he cautioned that “we cannot make comparisons to trials in which patients only got one immunotherapy. But this study confirms that consistency that patients who receive ipilimumab and nivolumab have superior responses compared to single-agent immunotherapy.”

He noted that all of the patients in the new study had all of their lymph nodes removed and called for doing that to remain the standard of care in terms of surgical approach.

“With short follow-up, it is too early to tell if some patients may have benefited from that adjuvant therapy. However, NADINA confirms that immunotherapy should be given to all patients with advanced melanoma before surgery, when possible, and establishes dual therapy with nivolumab and ipilimumab, as the standard of care in the appropriate patient,” Dr. Lowe said.
 

EFS Improvement Exceeds Expectations

In an interview, Rodabe N. Amaria, MD, a medical oncologist and professor at The University of Texas MD Anderson Cancer Center in Houston, agreed with Dr. Lowe’s assessment of the findings.

“For years we have been doing neoadjuvant immunotherapy trials, all with favorable results, but all relatively small, with data that was intriguing, but not necessarily definitive,” she said. “I see the data from the NADINA trial as being definitive and true evidence of the many advantages of neoadjuvant immunotherapy for clinical stage 3 melanoma ... This work builds on the data from the SWOG 1801 trial but also exceeds expectations with the 68% improvement in EFS appreciated with the dual combination immunotherapy regimen compared to adjuvant nivolumab.”

Additionally, the approximately 30% grade 3 or higher immune-mediated toxicity is reasonable and in keeping with known data, and this trial demonstrates clearly that neoadjuvant immunotherapy does not increase the rate of surgical complications, she said.

Dr. Amaria also considered that 59% of patients who achieved a major pathologic response were observed in the neoadjuvant setting to be a key finding.

This indicates thats “over half the patients could be spared additional immunotherapy and risk of further immune-mediated toxicities by having only two doses of neoadjuvant immunotherapy, she said.

The results “demonstrate the superiority of a neoadjuvant combination immunotherapy approach for patients with clinical stage III melanoma,” she added.

The study was funded by Bristol Myers-Squibb and the Australian government.

Dr. Blank disclosed ties with Immagene, Signature Oncology, AstraZeneca, Bristol-Myers Squibb, GenMab, GlaxoSmithKline, Lilly, MSD Oncology, Novartis, Pfizer, Pierre Fabre, Roche/Genentech, Third Rock Ventures, 4SC, NanoString Technologies, WO 2021/177822 A1, and Freshfields Bruckhaus Deringer. No other experts reported any relevant disclosures.

Almost sixty percent of patients with macroscopic stage III melanoma who were randomized to 6 weeks of neoadjuvant immunotherapy needed no further treatment after therapeutic lymph node dissection in the phase 3 NADINA trial.

These results set a new standard of care in this patient population, the study’s lead author, Christian U. Blank, MD, PhD, reported at the annual meeting of the American Society of Clinical Oncology in Chicago.

Dr. Blank, a hematologist/oncologist from the Netherlands Cancer Institute in Amsterdam, called the result “very special,” noting that the trial included an active comparator, rather than a placebo control.

“When we treat these patients with surgery only, the outcome … is very bad: The 5-year relapse-free survival is only 30% and the overall survival is only 50%. Adjuvant therapy improves relapse-free survival but not overall survival ...Thus, there is an urgent need for these patients for novel therapy approaches,” he said during a press conference at the meeting.
 

Study Methods and Results

The study included 423 patients with stage III de novo or recurrent pathologically proven resectable melanoma with at least 1 lymph node metastasis. Patients were randomized to either the experimental neoadjuvant arm (n = 212), or the standard treatment control arm (n = 211), which consisted of therapeutic lymph node dissection (TLND) followed by 12 cycles of adjuvant nivolumab (NIVO 480 mg every 4 weeks).

Patients in the experimental arm received two cycles of neoadjuvant ipilimumab (IPI 80 mg every 3 weeks) plus NIVO 240 mg for 3 weeks followed by TLND. Those with a major pathologic response (MPR), defined as less than 10% vital tumor cells in the post-neoadjuvant resection specimen, went straight to follow-up.

Those without an MPR received adjuvant therapy. For patients with BRAF wild-type, this involved 11 cycles of adjuvant NIVO (480 mg every 4 weeks), while BRAF-mutated patients received dabrafenib plus trametinib (150 mg b.i.d./2 mg once a day; 46 weeks).

The study met its primary endpoint — event-free survival (EFS) — at the first interim analysis. After a median follow-up of 9.9 months, the estimated EFS was 83.7% for neoadjuvant immunotherapy versus 57.2% for standard of care, (P less than .0001, hazard ratio [HR] = 0.32).

“When we look into the subgroups, for example BRAF-mutated status or BRAF-wild-type status ... you see for both groups also a highly statistically significant outcome favoring the neoadjuvant therapy with hazard ratios of 0.29 and 0.35,” said Dr. Blank.

In total, 59% of patients in the experimental arm had an MPR needing no further treatment. “This is important, because the patients that achieve a major pathologic response have excellent outcomes, with an EFS of 95%,” said Dr. Blank.

He added that those with a partial response had an EFS of 76%, and among those who had “nonresponse,” the EFS was 57% — the same as that of patients in the control arm.

Toxicities were considered transient and acceptable, with systemic treatment-related grade 3 or 4 events in 29.7% of the neoadjuvant arm and 14.7% of the adjuvant arm.

NADINA is the first neoadjuvant checkpoint inhibitor phase 3 study in melanoma and the first phase 3 trial in oncology testing a checkpoint inhibitor without chemotherapy, noted Dr. Blank.

“At the moment we see only additions of immunotherapy to the chemotherapy neoadjuvant arms, but here you see that we can also treat patients with pure immunotherapy.”
 

Neoadjuvant Therapy Defined as Standard of Care

When considered along with evidence from the phase 2 SWOG 1801 study (N Engl J Med. 2023;388:813-8), “NADINA defines neoadjuvant therapy as the new standard of care for macroscopic stage III melanoma “which means that all trials currently ongoing need to be amended from adjuvant comparators to neoadjuvant comparators,” he said.

Dr. Blank called the trial a “new template for other malignancies implementing a neoadjuvant immunotherapy regimen followed by a response-driven adjuvant therapy.

“I think we see at the moment only sandwich designs, and this is more sales driven than patient driven, because what we have seen is that if a patient achieves a really deep response, the patient doesn’t need an adjuvant part,” he said.

Commenting during the press conference, Michael Lowe, MD, said the result “confirms and shows for the first time in a phase 3 study that giving immunotherapy before surgery results in superior outcomes to giving immunotherapy only after surgery.”

Dr. Lowe, associate professor in the Division of Surgical Oncology, at Emory University School of Medicine, Atlanta, added that the study “also confirms that giving two immunotherapy drugs before surgery results in excellent responses.”

However, he cautioned that “we cannot make comparisons to trials in which patients only got one immunotherapy. But this study confirms that consistency that patients who receive ipilimumab and nivolumab have superior responses compared to single-agent immunotherapy.”

He noted that all of the patients in the new study had all of their lymph nodes removed and called for doing that to remain the standard of care in terms of surgical approach.

“With short follow-up, it is too early to tell if some patients may have benefited from that adjuvant therapy. However, NADINA confirms that immunotherapy should be given to all patients with advanced melanoma before surgery, when possible, and establishes dual therapy with nivolumab and ipilimumab, as the standard of care in the appropriate patient,” Dr. Lowe said.
 

EFS Improvement Exceeds Expectations

In an interview, Rodabe N. Amaria, MD, a medical oncologist and professor at The University of Texas MD Anderson Cancer Center in Houston, agreed with Dr. Lowe’s assessment of the findings.

“For years we have been doing neoadjuvant immunotherapy trials, all with favorable results, but all relatively small, with data that was intriguing, but not necessarily definitive,” she said. “I see the data from the NADINA trial as being definitive and true evidence of the many advantages of neoadjuvant immunotherapy for clinical stage 3 melanoma ... This work builds on the data from the SWOG 1801 trial but also exceeds expectations with the 68% improvement in EFS appreciated with the dual combination immunotherapy regimen compared to adjuvant nivolumab.”

Additionally, the approximately 30% grade 3 or higher immune-mediated toxicity is reasonable and in keeping with known data, and this trial demonstrates clearly that neoadjuvant immunotherapy does not increase the rate of surgical complications, she said.

Dr. Amaria also considered that 59% of patients who achieved a major pathologic response were observed in the neoadjuvant setting to be a key finding.

This indicates thats “over half the patients could be spared additional immunotherapy and risk of further immune-mediated toxicities by having only two doses of neoadjuvant immunotherapy, she said.

The results “demonstrate the superiority of a neoadjuvant combination immunotherapy approach for patients with clinical stage III melanoma,” she added.

The study was funded by Bristol Myers-Squibb and the Australian government.

Dr. Blank disclosed ties with Immagene, Signature Oncology, AstraZeneca, Bristol-Myers Squibb, GenMab, GlaxoSmithKline, Lilly, MSD Oncology, Novartis, Pfizer, Pierre Fabre, Roche/Genentech, Third Rock Ventures, 4SC, NanoString Technologies, WO 2021/177822 A1, and Freshfields Bruckhaus Deringer. No other experts reported any relevant disclosures.

Almost sixty percent of patients with macroscopic stage III melanoma who were randomized to 6 weeks of neoadjuvant immunotherapy needed no further treatment after therapeutic lymph node dissection in the phase 3 NADINA trial.

These results set a new standard of care in this patient population, the study’s lead author, Christian U. Blank, MD, PhD, reported at the annual meeting of the American Society of Clinical Oncology in Chicago.

Dr. Blank, a hematologist/oncologist from the Netherlands Cancer Institute in Amsterdam, called the result “very special,” noting that the trial included an active comparator, rather than a placebo control.

“When we treat these patients with surgery only, the outcome … is very bad: The 5-year relapse-free survival is only 30% and the overall survival is only 50%. Adjuvant therapy improves relapse-free survival but not overall survival ...Thus, there is an urgent need for these patients for novel therapy approaches,” he said during a press conference at the meeting.
 

Study Methods and Results

The study included 423 patients with stage III de novo or recurrent pathologically proven resectable melanoma with at least 1 lymph node metastasis. Patients were randomized to either the experimental neoadjuvant arm (n = 212), or the standard treatment control arm (n = 211), which consisted of therapeutic lymph node dissection (TLND) followed by 12 cycles of adjuvant nivolumab (NIVO 480 mg every 4 weeks).

Patients in the experimental arm received two cycles of neoadjuvant ipilimumab (IPI 80 mg every 3 weeks) plus NIVO 240 mg for 3 weeks followed by TLND. Those with a major pathologic response (MPR), defined as less than 10% vital tumor cells in the post-neoadjuvant resection specimen, went straight to follow-up.

Those without an MPR received adjuvant therapy. For patients with BRAF wild-type, this involved 11 cycles of adjuvant NIVO (480 mg every 4 weeks), while BRAF-mutated patients received dabrafenib plus trametinib (150 mg b.i.d./2 mg once a day; 46 weeks).

The study met its primary endpoint — event-free survival (EFS) — at the first interim analysis. After a median follow-up of 9.9 months, the estimated EFS was 83.7% for neoadjuvant immunotherapy versus 57.2% for standard of care, (P less than .0001, hazard ratio [HR] = 0.32).

“When we look into the subgroups, for example BRAF-mutated status or BRAF-wild-type status ... you see for both groups also a highly statistically significant outcome favoring the neoadjuvant therapy with hazard ratios of 0.29 and 0.35,” said Dr. Blank.

In total, 59% of patients in the experimental arm had an MPR needing no further treatment. “This is important, because the patients that achieve a major pathologic response have excellent outcomes, with an EFS of 95%,” said Dr. Blank.

He added that those with a partial response had an EFS of 76%, and among those who had “nonresponse,” the EFS was 57% — the same as that of patients in the control arm.

Toxicities were considered transient and acceptable, with systemic treatment-related grade 3 or 4 events in 29.7% of the neoadjuvant arm and 14.7% of the adjuvant arm.

NADINA is the first neoadjuvant checkpoint inhibitor phase 3 study in melanoma and the first phase 3 trial in oncology testing a checkpoint inhibitor without chemotherapy, noted Dr. Blank.

“At the moment we see only additions of immunotherapy to the chemotherapy neoadjuvant arms, but here you see that we can also treat patients with pure immunotherapy.”
 

Neoadjuvant Therapy Defined as Standard of Care

When considered along with evidence from the phase 2 SWOG 1801 study (N Engl J Med. 2023;388:813-8), “NADINA defines neoadjuvant therapy as the new standard of care for macroscopic stage III melanoma “which means that all trials currently ongoing need to be amended from adjuvant comparators to neoadjuvant comparators,” he said.

Dr. Blank called the trial a “new template for other malignancies implementing a neoadjuvant immunotherapy regimen followed by a response-driven adjuvant therapy.

“I think we see at the moment only sandwich designs, and this is more sales driven than patient driven, because what we have seen is that if a patient achieves a really deep response, the patient doesn’t need an adjuvant part,” he said.

Commenting during the press conference, Michael Lowe, MD, said the result “confirms and shows for the first time in a phase 3 study that giving immunotherapy before surgery results in superior outcomes to giving immunotherapy only after surgery.”

Dr. Lowe, associate professor in the Division of Surgical Oncology, at Emory University School of Medicine, Atlanta, added that the study “also confirms that giving two immunotherapy drugs before surgery results in excellent responses.”

However, he cautioned that “we cannot make comparisons to trials in which patients only got one immunotherapy. But this study confirms that consistency that patients who receive ipilimumab and nivolumab have superior responses compared to single-agent immunotherapy.”

He noted that all of the patients in the new study had all of their lymph nodes removed and called for doing that to remain the standard of care in terms of surgical approach.

“With short follow-up, it is too early to tell if some patients may have benefited from that adjuvant therapy. However, NADINA confirms that immunotherapy should be given to all patients with advanced melanoma before surgery, when possible, and establishes dual therapy with nivolumab and ipilimumab, as the standard of care in the appropriate patient,” Dr. Lowe said.
 

EFS Improvement Exceeds Expectations

In an interview, Rodabe N. Amaria, MD, a medical oncologist and professor at The University of Texas MD Anderson Cancer Center in Houston, agreed with Dr. Lowe’s assessment of the findings.

“For years we have been doing neoadjuvant immunotherapy trials, all with favorable results, but all relatively small, with data that was intriguing, but not necessarily definitive,” she said. “I see the data from the NADINA trial as being definitive and true evidence of the many advantages of neoadjuvant immunotherapy for clinical stage 3 melanoma ... This work builds on the data from the SWOG 1801 trial but also exceeds expectations with the 68% improvement in EFS appreciated with the dual combination immunotherapy regimen compared to adjuvant nivolumab.”

Additionally, the approximately 30% grade 3 or higher immune-mediated toxicity is reasonable and in keeping with known data, and this trial demonstrates clearly that neoadjuvant immunotherapy does not increase the rate of surgical complications, she said.

Dr. Amaria also considered that 59% of patients who achieved a major pathologic response were observed in the neoadjuvant setting to be a key finding.

This indicates thats “over half the patients could be spared additional immunotherapy and risk of further immune-mediated toxicities by having only two doses of neoadjuvant immunotherapy, she said.

The results “demonstrate the superiority of a neoadjuvant combination immunotherapy approach for patients with clinical stage III melanoma,” she added.

The study was funded by Bristol Myers-Squibb and the Australian government.

Dr. Blank disclosed ties with Immagene, Signature Oncology, AstraZeneca, Bristol-Myers Squibb, GenMab, GlaxoSmithKline, Lilly, MSD Oncology, Novartis, Pfizer, Pierre Fabre, Roche/Genentech, Third Rock Ventures, 4SC, NanoString Technologies, WO 2021/177822 A1, and Freshfields Bruckhaus Deringer. No other experts reported any relevant disclosures.

Routine removal of healthy lymph nodes should not be a part of ovarian cancer treatment, according to results of the CARACO trial.

Retroperitoneal pelvic and para-aortic lymphadenectomy (RPPL) in patients undergoing either primary or interval surgery during ovarian cancer treatment for advanced epithelial ovarian cancer (AEOC) resulted in no benefit and significant harm, the new study found.

“[RPPL] brings only toxicity and it does not increase survival ... because we have a lot of improvement with other treatments than surgery,” lead author Jean-Marc Classe, MD, PhD, said during a press conference at the annual meeting of the American Society of Clinical Oncology. “It’s a surgical de-escalation, because it is not useful.”

Enrollment for the multicenter, phase III CARACO trial stagnated after the LION trial (N Engl J Med . 2019 Feb 28;380[9]:822-832) showed no benefit to doing RPPL in patients undergoing primary surgery for AEOC. Ultimately, the CARACO trial did not enroll the prespecified sample size needed in order for the researchers to show that not doing RPPL was superior. 

Dr. Classe, a surgical oncologist at Nantes Université, in Nantes, France, explained that primary surgery is currently much less common than interval surgery for AEOC , thus it was important to design the CARACO trial to explore the risks and benefits of RPPL in a patient population that included more interval surgery.

CARACO enrolled 379 patients, with median age 64-65 years, and was closed prematurely due to stagnation of enrollment. Patients were randomized to no-RPPL (n = 193) or RPPL (n = 186), with about 75% in each arm receiving interval surgery (neoadjuvant chemotherapy, followed by cytoreductive surgery and adjuvant chemotherapy), and about 25% receiving primary surgery (initial cytoreductive surgery followed by adjuvant chemotherapy). There was a similar postsurgical rate of no residual disease (85.6% and 88.3% in the no-RPPL and RPPL groups, respectively), and lymph node metastases were diagnosed in 43% of the patients in the RPPL arm, with a median of 3 involved lymph nodes.

After a median follow-up of 9 years both the primary endpoint of progression-free survival (PFS), and secondary endpoint of overall survival (OS) showed no advantage to RPPL, with a median PFS of 14.8 months in the no-RPPL arm and 18.5 months in the RPPL arm (HR 0.96), and a median OS of 48.9 months and 58.0 months respectively (HR 0.92).

Surgery in the lymphadenectomy arm was 300 minutes versus 240 minutes.

“We observed statistically significant more morbidity in the lymphadenectomy arm with more transfusion (72 vs 57 patients), more re-intervention (15 vs 6 patients), more urinary injury (7 vs zero patients),” said Dr. Classe. Mortality was the same in both arms.

There were 314 events observed in the trial, which was 22 events fewer than the required sample size to show superiority. However, Dr. Classe said, a “worst-case scenario” calculation, assuming that all events would have favored lymphadenectomy, did not change the overall result.

The discussant for the trial, Shitanshu Uppal, MD, assistant professor in the division of gynecologic oncology at the University of Michigan in Ann Arbor, agreed that the study investigators adequately addressed this concern with the “counterfactual scenario.” He added that “as utilization of neoadjuvant chemotherapy goes up these results are really helpful in consolidating the results of the prior LION study, that lymph node dissection has no role in interval debulking surgery as well.”

Commenting on the study during the press conference, Michael Lowe, MD, associate professor in the division of surgical oncology at Emory University School of Medicine in Atlanta, said the CARACO study investigators’ efforts “underscore the difficulty of designing and accruing surgical clinical trials, especially clinical trials in which patients are offered less surgery.” He said the trial’s findings are consistent with other clinical trials in breast cancer and melanoma “that likewise showed similar outcomes for patients that did not undergo removal of clinically normal appearing lymph nodes.”

He pointed out that all of these studies highlight that the focus should turn to improving medical therapies.

Echoing this sentiment, Julie Gralow, MD, ASCO chief medical officer and executive vice-president, said, “it is very clear that lymph node dissection has significant morbidity ... and it’s very clear that we should not be doing more surgery than is needed ... In advanced ovarian cancer where the majority already have distant disease [focusing] on systemic therapy is probably what will have the most impact.”

Christina Annunziata, MD, PhD, senior vice president, Extramural Discovery Science, at the American Cancer Society, and an expert in ovarian cancer, said the analysis “leaves little doubt that there would be a statistically significant difference between the two arms. The numbers are small, but since this study results were consistent with the similar LION trial, I think that this study will tip the balance further towards omitting the lymphadenectomy in both primary and interval surgeries,” she said in an interview.

Dr. Annunziata added that surgeons are already omitting the dissection based on the LION study.

The study was funded by the French National Institute of Cancer. Dr. Classe disclosed consulting or advisory roles for GlaxoSmithKline, Myriad Genetics, and Roche.

None of the other experts interviewed for this piece declared having any relevant disclosures.

Routine removal of healthy lymph nodes should not be a part of ovarian cancer treatment, according to results of the CARACO trial.

Retroperitoneal pelvic and para-aortic lymphadenectomy (RPPL) in patients undergoing either primary or interval surgery during ovarian cancer treatment for advanced epithelial ovarian cancer (AEOC) resulted in no benefit and significant harm, the new study found.

“[RPPL] brings only toxicity and it does not increase survival ... because we have a lot of improvement with other treatments than surgery,” lead author Jean-Marc Classe, MD, PhD, said during a press conference at the annual meeting of the American Society of Clinical Oncology. “It’s a surgical de-escalation, because it is not useful.”

Enrollment for the multicenter, phase III CARACO trial stagnated after the LION trial (N Engl J Med . 2019 Feb 28;380[9]:822-832) showed no benefit to doing RPPL in patients undergoing primary surgery for AEOC. Ultimately, the CARACO trial did not enroll the prespecified sample size needed in order for the researchers to show that not doing RPPL was superior. 

Dr. Classe, a surgical oncologist at Nantes Université, in Nantes, France, explained that primary surgery is currently much less common than interval surgery for AEOC , thus it was important to design the CARACO trial to explore the risks and benefits of RPPL in a patient population that included more interval surgery.

CARACO enrolled 379 patients, with median age 64-65 years, and was closed prematurely due to stagnation of enrollment. Patients were randomized to no-RPPL (n = 193) or RPPL (n = 186), with about 75% in each arm receiving interval surgery (neoadjuvant chemotherapy, followed by cytoreductive surgery and adjuvant chemotherapy), and about 25% receiving primary surgery (initial cytoreductive surgery followed by adjuvant chemotherapy). There was a similar postsurgical rate of no residual disease (85.6% and 88.3% in the no-RPPL and RPPL groups, respectively), and lymph node metastases were diagnosed in 43% of the patients in the RPPL arm, with a median of 3 involved lymph nodes.

After a median follow-up of 9 years both the primary endpoint of progression-free survival (PFS), and secondary endpoint of overall survival (OS) showed no advantage to RPPL, with a median PFS of 14.8 months in the no-RPPL arm and 18.5 months in the RPPL arm (HR 0.96), and a median OS of 48.9 months and 58.0 months respectively (HR 0.92).

Surgery in the lymphadenectomy arm was 300 minutes versus 240 minutes.

“We observed statistically significant more morbidity in the lymphadenectomy arm with more transfusion (72 vs 57 patients), more re-intervention (15 vs 6 patients), more urinary injury (7 vs zero patients),” said Dr. Classe. Mortality was the same in both arms.

There were 314 events observed in the trial, which was 22 events fewer than the required sample size to show superiority. However, Dr. Classe said, a “worst-case scenario” calculation, assuming that all events would have favored lymphadenectomy, did not change the overall result.

The discussant for the trial, Shitanshu Uppal, MD, assistant professor in the division of gynecologic oncology at the University of Michigan in Ann Arbor, agreed that the study investigators adequately addressed this concern with the “counterfactual scenario.” He added that “as utilization of neoadjuvant chemotherapy goes up these results are really helpful in consolidating the results of the prior LION study, that lymph node dissection has no role in interval debulking surgery as well.”

Commenting on the study during the press conference, Michael Lowe, MD, associate professor in the division of surgical oncology at Emory University School of Medicine in Atlanta, said the CARACO study investigators’ efforts “underscore the difficulty of designing and accruing surgical clinical trials, especially clinical trials in which patients are offered less surgery.” He said the trial’s findings are consistent with other clinical trials in breast cancer and melanoma “that likewise showed similar outcomes for patients that did not undergo removal of clinically normal appearing lymph nodes.”

He pointed out that all of these studies highlight that the focus should turn to improving medical therapies.

Echoing this sentiment, Julie Gralow, MD, ASCO chief medical officer and executive vice-president, said, “it is very clear that lymph node dissection has significant morbidity ... and it’s very clear that we should not be doing more surgery than is needed ... In advanced ovarian cancer where the majority already have distant disease [focusing] on systemic therapy is probably what will have the most impact.”

Christina Annunziata, MD, PhD, senior vice president, Extramural Discovery Science, at the American Cancer Society, and an expert in ovarian cancer, said the analysis “leaves little doubt that there would be a statistically significant difference between the two arms. The numbers are small, but since this study results were consistent with the similar LION trial, I think that this study will tip the balance further towards omitting the lymphadenectomy in both primary and interval surgeries,” she said in an interview.

Dr. Annunziata added that surgeons are already omitting the dissection based on the LION study.

The study was funded by the French National Institute of Cancer. Dr. Classe disclosed consulting or advisory roles for GlaxoSmithKline, Myriad Genetics, and Roche.

None of the other experts interviewed for this piece declared having any relevant disclosures.

Routine removal of healthy lymph nodes should not be a part of ovarian cancer treatment, according to results of the CARACO trial.

Retroperitoneal pelvic and para-aortic lymphadenectomy (RPPL) in patients undergoing either primary or interval surgery during ovarian cancer treatment for advanced epithelial ovarian cancer (AEOC) resulted in no benefit and significant harm, the new study found.

“[RPPL] brings only toxicity and it does not increase survival ... because we have a lot of improvement with other treatments than surgery,” lead author Jean-Marc Classe, MD, PhD, said during a press conference at the annual meeting of the American Society of Clinical Oncology. “It’s a surgical de-escalation, because it is not useful.”

Enrollment for the multicenter, phase III CARACO trial stagnated after the LION trial (N Engl J Med . 2019 Feb 28;380[9]:822-832) showed no benefit to doing RPPL in patients undergoing primary surgery for AEOC. Ultimately, the CARACO trial did not enroll the prespecified sample size needed in order for the researchers to show that not doing RPPL was superior. 

Dr. Classe, a surgical oncologist at Nantes Université, in Nantes, France, explained that primary surgery is currently much less common than interval surgery for AEOC , thus it was important to design the CARACO trial to explore the risks and benefits of RPPL in a patient population that included more interval surgery.

CARACO enrolled 379 patients, with median age 64-65 years, and was closed prematurely due to stagnation of enrollment. Patients were randomized to no-RPPL (n = 193) or RPPL (n = 186), with about 75% in each arm receiving interval surgery (neoadjuvant chemotherapy, followed by cytoreductive surgery and adjuvant chemotherapy), and about 25% receiving primary surgery (initial cytoreductive surgery followed by adjuvant chemotherapy). There was a similar postsurgical rate of no residual disease (85.6% and 88.3% in the no-RPPL and RPPL groups, respectively), and lymph node metastases were diagnosed in 43% of the patients in the RPPL arm, with a median of 3 involved lymph nodes.

After a median follow-up of 9 years both the primary endpoint of progression-free survival (PFS), and secondary endpoint of overall survival (OS) showed no advantage to RPPL, with a median PFS of 14.8 months in the no-RPPL arm and 18.5 months in the RPPL arm (HR 0.96), and a median OS of 48.9 months and 58.0 months respectively (HR 0.92).

Surgery in the lymphadenectomy arm was 300 minutes versus 240 minutes.

“We observed statistically significant more morbidity in the lymphadenectomy arm with more transfusion (72 vs 57 patients), more re-intervention (15 vs 6 patients), more urinary injury (7 vs zero patients),” said Dr. Classe. Mortality was the same in both arms.

There were 314 events observed in the trial, which was 22 events fewer than the required sample size to show superiority. However, Dr. Classe said, a “worst-case scenario” calculation, assuming that all events would have favored lymphadenectomy, did not change the overall result.

The discussant for the trial, Shitanshu Uppal, MD, assistant professor in the division of gynecologic oncology at the University of Michigan in Ann Arbor, agreed that the study investigators adequately addressed this concern with the “counterfactual scenario.” He added that “as utilization of neoadjuvant chemotherapy goes up these results are really helpful in consolidating the results of the prior LION study, that lymph node dissection has no role in interval debulking surgery as well.”

Commenting on the study during the press conference, Michael Lowe, MD, associate professor in the division of surgical oncology at Emory University School of Medicine in Atlanta, said the CARACO study investigators’ efforts “underscore the difficulty of designing and accruing surgical clinical trials, especially clinical trials in which patients are offered less surgery.” He said the trial’s findings are consistent with other clinical trials in breast cancer and melanoma “that likewise showed similar outcomes for patients that did not undergo removal of clinically normal appearing lymph nodes.”

He pointed out that all of these studies highlight that the focus should turn to improving medical therapies.

Echoing this sentiment, Julie Gralow, MD, ASCO chief medical officer and executive vice-president, said, “it is very clear that lymph node dissection has significant morbidity ... and it’s very clear that we should not be doing more surgery than is needed ... In advanced ovarian cancer where the majority already have distant disease [focusing] on systemic therapy is probably what will have the most impact.”

Christina Annunziata, MD, PhD, senior vice president, Extramural Discovery Science, at the American Cancer Society, and an expert in ovarian cancer, said the analysis “leaves little doubt that there would be a statistically significant difference between the two arms. The numbers are small, but since this study results were consistent with the similar LION trial, I think that this study will tip the balance further towards omitting the lymphadenectomy in both primary and interval surgeries,” she said in an interview.

Dr. Annunziata added that surgeons are already omitting the dissection based on the LION study.

The study was funded by the French National Institute of Cancer. Dr. Classe disclosed consulting or advisory roles for GlaxoSmithKline, Myriad Genetics, and Roche.

None of the other experts interviewed for this piece declared having any relevant disclosures.

The addition of abemaciclib to fulvestrant significantly improved progression-free survival for patients with hormone receptor positive, HER2 negative advanced breast cancer who had been previously treated with cyclin-dependent kinase 4 and 6 inhibitor plus endocrine therapy, in a new study.

Disease progression is common in these patients, for whom first-line treatment is cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors plus endocrine therapy, Kevin Kalinsky, MD, of the Winship Cancer Institute of Emory University, Atlanta, said in a presentation at the American Society of Clinical Oncology (ASCO) annual meeting.

A need exists for additional targeted therapies for patients with advanced hormone receptor (HR)+, HER2- breast cancer whose tumors have progressed on endocrine therapy plus a CDK4/6 inhibitor, he said.

Data on the benefits of continuing CDK4/6 inhibitor therapy after progression have been mixed in phase 2 trials, Dr. Kalinsky noted in his presentation. Abemaciclib, an oral CDK4/6 inhibitor, has shown more selectivity for CDK 4 than CDK 6, and is approved in combination with fulvestrant or an aromatase inhibitor for advanced breast cancer, he said.

In a phase 3 study known as postMONARCH, the researchers randomized 182 patients to abemaciclib plus fulvestrant and 186 to placebo plus fulvestrant. The primary endpoint was progression-free survival (PFS) based on investigator assessment; secondary endpoints included PFS based on blinded independent central review (BICR), objective response rate (ORR), and safety.

The PFS rates at 6 months were 50% and 37% for the abemaciclib and placebo arms, respectively.

In the primary analysis, abemaciclib led to a 27% reduction in risk of investigator-assessed progression-free survival events compared with the placebo (117 vs. 141 events, hazard ratio 0.73, P = 0.02).

The study population included men and pre- and postmenopausal women with advanced HR+, HER2- breast cancer and progression after initial CDK4/6 plus endocrine therapy from 96 centers in 16 countries, enrolled between March 2022 and June 2023. The median age of the patients in the abemaciclib and placebo groups was 58 years and 61 years, respectively. Patients underwent scans every 8 weeks for the first 12 months, then every 12 weeks. Most of the patients were enrolled immediately after CDK4/6i + ET as initial therapy for advanced breast cancer. The most common previous CDK4/6 inhibitor therapy was palbociclib (59%), followed by ribociclib (33%) and abemaciclib (8%).
 

Secondary Endpoints Also Favor Abemaciclib

The effects in favor of abemaciclib were consistent across subgroups, regardless of the presence or absence of baseline genetic mutations (ESR1 or PIK3CA), Dr. Kalinsky said in his presentation.

Overall response rate was significantly improved in the abemaciclib group compared with the placebo group in patients with measurable disease (17% vs. 7%) and PFS according to BICR also significantly improved (HR 0.55).

The magnitude of benefit was less in the subgroup of patients with visceral metastases, Dr. Kalinsky noted.

“Safety was consistent with what is known about the abemaciclib profile,” he added. Six percent of abemaciclib patients discontinued treatment because of adverse events.

The study is the first phase 3 trial to show improvement with CDK4/6 inhibition therapy with a combination of abemaciclib and fulvestrant and offers a new option for patients with HR+, HER2- advanced breast cancer not selected for biomarker status, Dr. Kalinsky concluded.
 

Data Support Switching CDK Inhibitors in Absence of Mutations

Switching CDK inhibitors to abemaciclib plus endocrine therapy significantly prolonged progression-free survival compared with endocrine therapy alone, with especially pronounced improvement in those without visceral metastases and those with longer durations of first-line CKD4/6 inhibitor therapy, said Ruth O’Regan, MD, of the University of Rochester, New York, who served as the discussant for the new research.

Dr. Regan referenced the improvement with abemaciclib in the BICR, a technique used to identify potential bias introduced by the assessment of local investigators. This can result in more favorable PFS on a treatment arm as seen in this study, but its use generally does not impact overall trial results, she said.

In the context of other studies involving switching CDK 4/6 inhibitors post-progression, the difference of 0.7 months in PFS between the abemaciclib and placebo groups was less than the 2.5 months difference seen in the MAINTAIN trial and the 1.3 months difference seen in the PALMIRA trial, Dr. O’Regan said in her presentation. Conversely, in the PACE trial, the intervention group did worse (4.6 months) than the control group in terms of the PFS (4.8 months), she said. Overall, the results of the postMONARCH trial support the use abemaciclib in patients with no actionable genetic mutation, she said.

In a question-and-answer session, Dr. Kalinsky was asked whether clinicians should still bother with genetic testing, since patients in the current study showed benefits regardless of the presence or absence of a mutation.

“I would still recommend that we check for mutations,” he emphasized. The current study “is one chapter in a much larger book,” and the field continues to evolve, he said.
 

A Clinician’s Take

“Currently, no standard second-line treatment after progression on first line CDK4/6 inhibitor plus endocrine therapy exists,” Malinda T. West, MD, of the University of Wisconsin, Madison, said in an interview. “Using a different CDK4/6 inhibitor after progression on a first CDK4/6 inhibitor has mixed data,” she said.

“If benefit with a second CDK4/6 inhibitor is confirmed, it may represent an additional low toxicity, chemotherapy-sparing regimen,” she noted.

Earlier data from the MAINTAIN trial had shown benefit with using ribociclib after progression on a primarily first line palbociclib, though other trials looking at use of palbociclib after progression on CDK 4/6 inhibitor [including the PACE and PALMIRA trials] had not, she said.

Overall, the results from postMONARCH support that switching the CDK4/6 inhibitor at progression to ribociclib or abemaciclib may be another treatment option, and reasonable for patients who don’t have other actionable mutations, Dr. West told this news organization.

The study was supported by Eli Lilly. Dr. Kalinsky disclosed that immediate family members are employed by EQRx and GRAIL, with stock or other ownership interests in these companies. He disclosed consulting or advisory roles with 4D Pharma; AstraZeneca; Cullinan Oncology; Daiichi Sankyo/AstraZeneca; eFFECTOR Therapeutics; Genentech/Roche; Immunomedics; Lilly; Menarini Silicon Biosystems; Merck; Mersana; Myovant Sciences; Novartis; Oncosec; Prelude Therapeutics; Puma Biotechnology; RayzeBio; Seagen; and Takeda. Dr. Kalinsky further disclosed research funding to his institution from Ascentage Pharma; AstraZeneca; Daiichi Sankyo; Genentech/Roche; Lilly; Novartis; and Seagen, and relationships with Genentech and Immunomedics.

Dr. O’Regan disclosed honoraria from AstraZeneca/MedImmune; bioTheranostics; Gilead Sciences; Novartis; Pfizer; Puma Biotechnology; and Seagen, serving as a consultant or adviser for AstraZeneca/MedImmune; bioTheranostics; Lilly; Novartis; Puma Biotechnology; and Seagen, and funding to her institution from Novartis and Puma Biotechnology.

Dr. West, who was not involved in the new research or other studies mentioned in this article, had no financial conflicts to disclose.

The addition of abemaciclib to fulvestrant significantly improved progression-free survival for patients with hormone receptor positive, HER2 negative advanced breast cancer who had been previously treated with cyclin-dependent kinase 4 and 6 inhibitor plus endocrine therapy, in a new study.

Disease progression is common in these patients, for whom first-line treatment is cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors plus endocrine therapy, Kevin Kalinsky, MD, of the Winship Cancer Institute of Emory University, Atlanta, said in a presentation at the American Society of Clinical Oncology (ASCO) annual meeting.

A need exists for additional targeted therapies for patients with advanced hormone receptor (HR)+, HER2- breast cancer whose tumors have progressed on endocrine therapy plus a CDK4/6 inhibitor, he said.

Data on the benefits of continuing CDK4/6 inhibitor therapy after progression have been mixed in phase 2 trials, Dr. Kalinsky noted in his presentation. Abemaciclib, an oral CDK4/6 inhibitor, has shown more selectivity for CDK 4 than CDK 6, and is approved in combination with fulvestrant or an aromatase inhibitor for advanced breast cancer, he said.

In a phase 3 study known as postMONARCH, the researchers randomized 182 patients to abemaciclib plus fulvestrant and 186 to placebo plus fulvestrant. The primary endpoint was progression-free survival (PFS) based on investigator assessment; secondary endpoints included PFS based on blinded independent central review (BICR), objective response rate (ORR), and safety.

The PFS rates at 6 months were 50% and 37% for the abemaciclib and placebo arms, respectively.

In the primary analysis, abemaciclib led to a 27% reduction in risk of investigator-assessed progression-free survival events compared with the placebo (117 vs. 141 events, hazard ratio 0.73, P = 0.02).

The study population included men and pre- and postmenopausal women with advanced HR+, HER2- breast cancer and progression after initial CDK4/6 plus endocrine therapy from 96 centers in 16 countries, enrolled between March 2022 and June 2023. The median age of the patients in the abemaciclib and placebo groups was 58 years and 61 years, respectively. Patients underwent scans every 8 weeks for the first 12 months, then every 12 weeks. Most of the patients were enrolled immediately after CDK4/6i + ET as initial therapy for advanced breast cancer. The most common previous CDK4/6 inhibitor therapy was palbociclib (59%), followed by ribociclib (33%) and abemaciclib (8%).
 

Secondary Endpoints Also Favor Abemaciclib

The effects in favor of abemaciclib were consistent across subgroups, regardless of the presence or absence of baseline genetic mutations (ESR1 or PIK3CA), Dr. Kalinsky said in his presentation.

Overall response rate was significantly improved in the abemaciclib group compared with the placebo group in patients with measurable disease (17% vs. 7%) and PFS according to BICR also significantly improved (HR 0.55).

The magnitude of benefit was less in the subgroup of patients with visceral metastases, Dr. Kalinsky noted.

“Safety was consistent with what is known about the abemaciclib profile,” he added. Six percent of abemaciclib patients discontinued treatment because of adverse events.

The study is the first phase 3 trial to show improvement with CDK4/6 inhibition therapy with a combination of abemaciclib and fulvestrant and offers a new option for patients with HR+, HER2- advanced breast cancer not selected for biomarker status, Dr. Kalinsky concluded.
 

Data Support Switching CDK Inhibitors in Absence of Mutations

Switching CDK inhibitors to abemaciclib plus endocrine therapy significantly prolonged progression-free survival compared with endocrine therapy alone, with especially pronounced improvement in those without visceral metastases and those with longer durations of first-line CKD4/6 inhibitor therapy, said Ruth O’Regan, MD, of the University of Rochester, New York, who served as the discussant for the new research.

Dr. Regan referenced the improvement with abemaciclib in the BICR, a technique used to identify potential bias introduced by the assessment of local investigators. This can result in more favorable PFS on a treatment arm as seen in this study, but its use generally does not impact overall trial results, she said.

In the context of other studies involving switching CDK 4/6 inhibitors post-progression, the difference of 0.7 months in PFS between the abemaciclib and placebo groups was less than the 2.5 months difference seen in the MAINTAIN trial and the 1.3 months difference seen in the PALMIRA trial, Dr. O’Regan said in her presentation. Conversely, in the PACE trial, the intervention group did worse (4.6 months) than the control group in terms of the PFS (4.8 months), she said. Overall, the results of the postMONARCH trial support the use abemaciclib in patients with no actionable genetic mutation, she said.

In a question-and-answer session, Dr. Kalinsky was asked whether clinicians should still bother with genetic testing, since patients in the current study showed benefits regardless of the presence or absence of a mutation.

“I would still recommend that we check for mutations,” he emphasized. The current study “is one chapter in a much larger book,” and the field continues to evolve, he said.
 

A Clinician’s Take

“Currently, no standard second-line treatment after progression on first line CDK4/6 inhibitor plus endocrine therapy exists,” Malinda T. West, MD, of the University of Wisconsin, Madison, said in an interview. “Using a different CDK4/6 inhibitor after progression on a first CDK4/6 inhibitor has mixed data,” she said.

“If benefit with a second CDK4/6 inhibitor is confirmed, it may represent an additional low toxicity, chemotherapy-sparing regimen,” she noted.

Earlier data from the MAINTAIN trial had shown benefit with using ribociclib after progression on a primarily first line palbociclib, though other trials looking at use of palbociclib after progression on CDK 4/6 inhibitor [including the PACE and PALMIRA trials] had not, she said.

Overall, the results from postMONARCH support that switching the CDK4/6 inhibitor at progression to ribociclib or abemaciclib may be another treatment option, and reasonable for patients who don’t have other actionable mutations, Dr. West told this news organization.

The study was supported by Eli Lilly. Dr. Kalinsky disclosed that immediate family members are employed by EQRx and GRAIL, with stock or other ownership interests in these companies. He disclosed consulting or advisory roles with 4D Pharma; AstraZeneca; Cullinan Oncology; Daiichi Sankyo/AstraZeneca; eFFECTOR Therapeutics; Genentech/Roche; Immunomedics; Lilly; Menarini Silicon Biosystems; Merck; Mersana; Myovant Sciences; Novartis; Oncosec; Prelude Therapeutics; Puma Biotechnology; RayzeBio; Seagen; and Takeda. Dr. Kalinsky further disclosed research funding to his institution from Ascentage Pharma; AstraZeneca; Daiichi Sankyo; Genentech/Roche; Lilly; Novartis; and Seagen, and relationships with Genentech and Immunomedics.

Dr. O’Regan disclosed honoraria from AstraZeneca/MedImmune; bioTheranostics; Gilead Sciences; Novartis; Pfizer; Puma Biotechnology; and Seagen, serving as a consultant or adviser for AstraZeneca/MedImmune; bioTheranostics; Lilly; Novartis; Puma Biotechnology; and Seagen, and funding to her institution from Novartis and Puma Biotechnology.

Dr. West, who was not involved in the new research or other studies mentioned in this article, had no financial conflicts to disclose.

The addition of abemaciclib to fulvestrant significantly improved progression-free survival for patients with hormone receptor positive, HER2 negative advanced breast cancer who had been previously treated with cyclin-dependent kinase 4 and 6 inhibitor plus endocrine therapy, in a new study.

Disease progression is common in these patients, for whom first-line treatment is cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors plus endocrine therapy, Kevin Kalinsky, MD, of the Winship Cancer Institute of Emory University, Atlanta, said in a presentation at the American Society of Clinical Oncology (ASCO) annual meeting.

A need exists for additional targeted therapies for patients with advanced hormone receptor (HR)+, HER2- breast cancer whose tumors have progressed on endocrine therapy plus a CDK4/6 inhibitor, he said.

Data on the benefits of continuing CDK4/6 inhibitor therapy after progression have been mixed in phase 2 trials, Dr. Kalinsky noted in his presentation. Abemaciclib, an oral CDK4/6 inhibitor, has shown more selectivity for CDK 4 than CDK 6, and is approved in combination with fulvestrant or an aromatase inhibitor for advanced breast cancer, he said.

In a phase 3 study known as postMONARCH, the researchers randomized 182 patients to abemaciclib plus fulvestrant and 186 to placebo plus fulvestrant. The primary endpoint was progression-free survival (PFS) based on investigator assessment; secondary endpoints included PFS based on blinded independent central review (BICR), objective response rate (ORR), and safety.

The PFS rates at 6 months were 50% and 37% for the abemaciclib and placebo arms, respectively.

In the primary analysis, abemaciclib led to a 27% reduction in risk of investigator-assessed progression-free survival events compared with the placebo (117 vs. 141 events, hazard ratio 0.73, P = 0.02).

The study population included men and pre- and postmenopausal women with advanced HR+, HER2- breast cancer and progression after initial CDK4/6 plus endocrine therapy from 96 centers in 16 countries, enrolled between March 2022 and June 2023. The median age of the patients in the abemaciclib and placebo groups was 58 years and 61 years, respectively. Patients underwent scans every 8 weeks for the first 12 months, then every 12 weeks. Most of the patients were enrolled immediately after CDK4/6i + ET as initial therapy for advanced breast cancer. The most common previous CDK4/6 inhibitor therapy was palbociclib (59%), followed by ribociclib (33%) and abemaciclib (8%).
 

Secondary Endpoints Also Favor Abemaciclib

The effects in favor of abemaciclib were consistent across subgroups, regardless of the presence or absence of baseline genetic mutations (ESR1 or PIK3CA), Dr. Kalinsky said in his presentation.

Overall response rate was significantly improved in the abemaciclib group compared with the placebo group in patients with measurable disease (17% vs. 7%) and PFS according to BICR also significantly improved (HR 0.55).

The magnitude of benefit was less in the subgroup of patients with visceral metastases, Dr. Kalinsky noted.

“Safety was consistent with what is known about the abemaciclib profile,” he added. Six percent of abemaciclib patients discontinued treatment because of adverse events.

The study is the first phase 3 trial to show improvement with CDK4/6 inhibition therapy with a combination of abemaciclib and fulvestrant and offers a new option for patients with HR+, HER2- advanced breast cancer not selected for biomarker status, Dr. Kalinsky concluded.
 

Data Support Switching CDK Inhibitors in Absence of Mutations

Switching CDK inhibitors to abemaciclib plus endocrine therapy significantly prolonged progression-free survival compared with endocrine therapy alone, with especially pronounced improvement in those without visceral metastases and those with longer durations of first-line CKD4/6 inhibitor therapy, said Ruth O’Regan, MD, of the University of Rochester, New York, who served as the discussant for the new research.

Dr. Regan referenced the improvement with abemaciclib in the BICR, a technique used to identify potential bias introduced by the assessment of local investigators. This can result in more favorable PFS on a treatment arm as seen in this study, but its use generally does not impact overall trial results, she said.

In the context of other studies involving switching CDK 4/6 inhibitors post-progression, the difference of 0.7 months in PFS between the abemaciclib and placebo groups was less than the 2.5 months difference seen in the MAINTAIN trial and the 1.3 months difference seen in the PALMIRA trial, Dr. O’Regan said in her presentation. Conversely, in the PACE trial, the intervention group did worse (4.6 months) than the control group in terms of the PFS (4.8 months), she said. Overall, the results of the postMONARCH trial support the use abemaciclib in patients with no actionable genetic mutation, she said.

In a question-and-answer session, Dr. Kalinsky was asked whether clinicians should still bother with genetic testing, since patients in the current study showed benefits regardless of the presence or absence of a mutation.

“I would still recommend that we check for mutations,” he emphasized. The current study “is one chapter in a much larger book,” and the field continues to evolve, he said.
 

A Clinician’s Take

“Currently, no standard second-line treatment after progression on first line CDK4/6 inhibitor plus endocrine therapy exists,” Malinda T. West, MD, of the University of Wisconsin, Madison, said in an interview. “Using a different CDK4/6 inhibitor after progression on a first CDK4/6 inhibitor has mixed data,” she said.

“If benefit with a second CDK4/6 inhibitor is confirmed, it may represent an additional low toxicity, chemotherapy-sparing regimen,” she noted.

Earlier data from the MAINTAIN trial had shown benefit with using ribociclib after progression on a primarily first line palbociclib, though other trials looking at use of palbociclib after progression on CDK 4/6 inhibitor [including the PACE and PALMIRA trials] had not, she said.

Overall, the results from postMONARCH support that switching the CDK4/6 inhibitor at progression to ribociclib or abemaciclib may be another treatment option, and reasonable for patients who don’t have other actionable mutations, Dr. West told this news organization.

The study was supported by Eli Lilly. Dr. Kalinsky disclosed that immediate family members are employed by EQRx and GRAIL, with stock or other ownership interests in these companies. He disclosed consulting or advisory roles with 4D Pharma; AstraZeneca; Cullinan Oncology; Daiichi Sankyo/AstraZeneca; eFFECTOR Therapeutics; Genentech/Roche; Immunomedics; Lilly; Menarini Silicon Biosystems; Merck; Mersana; Myovant Sciences; Novartis; Oncosec; Prelude Therapeutics; Puma Biotechnology; RayzeBio; Seagen; and Takeda. Dr. Kalinsky further disclosed research funding to his institution from Ascentage Pharma; AstraZeneca; Daiichi Sankyo; Genentech/Roche; Lilly; Novartis; and Seagen, and relationships with Genentech and Immunomedics.

Dr. O’Regan disclosed honoraria from AstraZeneca/MedImmune; bioTheranostics; Gilead Sciences; Novartis; Pfizer; Puma Biotechnology; and Seagen, serving as a consultant or adviser for AstraZeneca/MedImmune; bioTheranostics; Lilly; Novartis; Puma Biotechnology; and Seagen, and funding to her institution from Novartis and Puma Biotechnology.

Dr. West, who was not involved in the new research or other studies mentioned in this article, had no financial conflicts to disclose.

Over the past few years, several new, highly effective treatment strategies have improved survival outcomes in patients with early breast cancer.

“We’ve been very fortunate” to see these advances, Sara M. Tolaney, MD, MPH, chief, Division of Breast Oncology, Dana-Farber Cancer Institute, Boston, told attendees at the European Society of Medical Oncology (ESMO) Breast Cancer annual congress.

However, Dr. Tolaney noted, these new treatment approaches can come with big limitations — namely, potential overtreatment of some patients as well as short- and long-term toxicities, some of which can be life-threatening.

These caveats have prompted trials exploring strategies to de-escalate therapy, which essentially means providing the right amount of treatment to the right patient at the right time, said Dr. Tolaney. The goal is to “right-size” or “optimize therapy” to maintain strong outcomes while mitigating side effects.

De-escalation studies are “critical to preserving quality of life” and affect the cost-effectiveness of therapy, she explained.

But, she added, de-escalation trials are “not a very attractive strategy to pharmaceutical companies” and can be challenging for researchers to conduct. These trials may, for instance, lack adequate sample sizes and sufficient statistical power, which can interfere with achieving clinically meaningful findings that may affect practice.

That is why carefully designing de-escalation trials is crucial, Dr. Tolaney said.

In her talk at ESMO Breast, Dr. Tolaney highlighted several strategies for designing these trials.

One strategy is to shorten the duration of therapy, said Dr. Tolaney.

This approach was explored in the PHARE and PERSEPHONE trials, which looked at 6 vs 12 months of trastuzumab in nonmetastatic breast cancer. Other trials, such as GeparNuevo and KEYNOTE-522, explored whether adjuvant checkpoint inhibitor therapy was needed, or could be skipped, following neoadjuvant therapy. This approach requires establishing noninferiority, or similar efficacy, between the standard of care and the shorter duration of therapy.

A second strategy is to remove part of the chemotherapy regimen, typically the most toxic agent, Dr. Tolaney continued.

Conducting a prospective, randomized trial exploring this approach in human epidermal growth factor receptor 2–positive (HER2+) early breast cancer, for example, would be difficult for a range of reasons, such as the need to enroll thousands of patients.

Dr. Tolaney and colleagues, however, designed a nonrandomized prospective study — the APT trial — with just over 400 patients to assess adjuvant paclitaxel plus trastuzumab in patients with node-negative HER2+ disease. The open-label, single-arm, phase 2 APT trial found that adjuvant paclitaxel and trastuzumab led to a 10-year recurrence-free interval of 96.3%, 10-year overall survival of 94.3%, and 10-year breast cancer–specific survival of 98.8%.

Outcomes with this adjuvant regimen were comparable to previous findings in historical controls who received doxorubicin, cyclophosphamide, paclitaxel, and trastuzumab or docetaxel, carboplatin, and trastuzumab.

Dr. Tolaney concluded that given few events, “it’s unlikely we need to escalate therapy to do better for most patients,” and the APT regimen “can be considered a reasonable and appealing approach for the majority of patients” with node-negative HER2+ breast cancer.

“A single-arm design for a de-escalation study can be practice-changing but only if there are very few recurrences,” Dr. Tolaney said.

Substituting chemotherapy with a targeted, potentially less-toxic agent is a third de-escalation approach. The ATEMPT trial compared patients receiving trastuzumab emtansine (T-DM1) with those receiving paclitaxel plus trastuzumab followed by maintenance trastuzumab.

Investigators found that de-escalation with T-DM1 was associated with very few recurrences but similar rates of certain adverse events, including grade 2 or higher neurotoxicity, febrile neutropenia, and grade 4 or higher hematologic toxicity.

However, there are questions about how to define “less toxic,” Dr. Tolaney said. The trial found, for instance, that T-DM1 did have some advantages — patients reported better quality of life and experienced less alopecia and neurotoxicity, as well as a less severe impact on fertility.

Understanding the right endpoint to demonstrate less toxicity is critical, “as we start to think about how to replace standard chemotherapies with better targeted drugs,” she added.

The ATEMPT 2.0 trial, which is currently enrolling, will aim to answer some of these questions about defining and demonstrating less toxicity, she said.

Finally, some researchers are attempting to omit chemotherapy altogether with the help of biomarkers. The TAILORx trial, for instance, aimed to stratify patients with early-stage breast cancer by clinical risk factors combined with a 21-gene expression assay and found that adjuvant chemotherapy was not necessary in a large proportion of these women.

On the biomarker front, oncologists might be able to use ctDNA to guide decision-making and personalize therapy, Tolaney said. The presence of ctDNA is associated with an almost 100% likelihood of having a recurrence, whereas its absence suggests better outcomes, she explained.

Oncologists could use the presence or absence of ctDNA to guide next steps — assign patients to follow-up assessments when ctDNA is not present or to standard or experimental treatment when it is present. It may also be possible to leverage the presence of minimal residual disease to help direct treatment choices.

But ctDNA is currently not as perfect a predictor of outcome as it could be, she cautioned. “We need more sensitive assays [so] I’m not sure we’re quite ready to use lack of ctDNA to de-escalate treatment,” she said.

Dr. Tolaney declared relationships with Novartis, Pfizer, Merck, Lilly, AstraZeneca, Genentech/Roche, Eisai, Sanofi, Bristol Myers Squib, and other companies.

A version of this article appeared on Medscape.com .

Over the past few years, several new, highly effective treatment strategies have improved survival outcomes in patients with early breast cancer.

“We’ve been very fortunate” to see these advances, Sara M. Tolaney, MD, MPH, chief, Division of Breast Oncology, Dana-Farber Cancer Institute, Boston, told attendees at the European Society of Medical Oncology (ESMO) Breast Cancer annual congress.

However, Dr. Tolaney noted, these new treatment approaches can come with big limitations — namely, potential overtreatment of some patients as well as short- and long-term toxicities, some of which can be life-threatening.

These caveats have prompted trials exploring strategies to de-escalate therapy, which essentially means providing the right amount of treatment to the right patient at the right time, said Dr. Tolaney. The goal is to “right-size” or “optimize therapy” to maintain strong outcomes while mitigating side effects.

De-escalation studies are “critical to preserving quality of life” and affect the cost-effectiveness of therapy, she explained.

But, she added, de-escalation trials are “not a very attractive strategy to pharmaceutical companies” and can be challenging for researchers to conduct. These trials may, for instance, lack adequate sample sizes and sufficient statistical power, which can interfere with achieving clinically meaningful findings that may affect practice.

That is why carefully designing de-escalation trials is crucial, Dr. Tolaney said.

In her talk at ESMO Breast, Dr. Tolaney highlighted several strategies for designing these trials.

One strategy is to shorten the duration of therapy, said Dr. Tolaney.

This approach was explored in the PHARE and PERSEPHONE trials, which looked at 6 vs 12 months of trastuzumab in nonmetastatic breast cancer. Other trials, such as GeparNuevo and KEYNOTE-522, explored whether adjuvant checkpoint inhibitor therapy was needed, or could be skipped, following neoadjuvant therapy. This approach requires establishing noninferiority, or similar efficacy, between the standard of care and the shorter duration of therapy.

A second strategy is to remove part of the chemotherapy regimen, typically the most toxic agent, Dr. Tolaney continued.

Conducting a prospective, randomized trial exploring this approach in human epidermal growth factor receptor 2–positive (HER2+) early breast cancer, for example, would be difficult for a range of reasons, such as the need to enroll thousands of patients.

Dr. Tolaney and colleagues, however, designed a nonrandomized prospective study — the APT trial — with just over 400 patients to assess adjuvant paclitaxel plus trastuzumab in patients with node-negative HER2+ disease. The open-label, single-arm, phase 2 APT trial found that adjuvant paclitaxel and trastuzumab led to a 10-year recurrence-free interval of 96.3%, 10-year overall survival of 94.3%, and 10-year breast cancer–specific survival of 98.8%.

Outcomes with this adjuvant regimen were comparable to previous findings in historical controls who received doxorubicin, cyclophosphamide, paclitaxel, and trastuzumab or docetaxel, carboplatin, and trastuzumab.

Dr. Tolaney concluded that given few events, “it’s unlikely we need to escalate therapy to do better for most patients,” and the APT regimen “can be considered a reasonable and appealing approach for the majority of patients” with node-negative HER2+ breast cancer.

“A single-arm design for a de-escalation study can be practice-changing but only if there are very few recurrences,” Dr. Tolaney said.

Substituting chemotherapy with a targeted, potentially less-toxic agent is a third de-escalation approach. The ATEMPT trial compared patients receiving trastuzumab emtansine (T-DM1) with those receiving paclitaxel plus trastuzumab followed by maintenance trastuzumab.

Investigators found that de-escalation with T-DM1 was associated with very few recurrences but similar rates of certain adverse events, including grade 2 or higher neurotoxicity, febrile neutropenia, and grade 4 or higher hematologic toxicity.

However, there are questions about how to define “less toxic,” Dr. Tolaney said. The trial found, for instance, that T-DM1 did have some advantages — patients reported better quality of life and experienced less alopecia and neurotoxicity, as well as a less severe impact on fertility.

Understanding the right endpoint to demonstrate less toxicity is critical, “as we start to think about how to replace standard chemotherapies with better targeted drugs,” she added.

The ATEMPT 2.0 trial, which is currently enrolling, will aim to answer some of these questions about defining and demonstrating less toxicity, she said.

Finally, some researchers are attempting to omit chemotherapy altogether with the help of biomarkers. The TAILORx trial, for instance, aimed to stratify patients with early-stage breast cancer by clinical risk factors combined with a 21-gene expression assay and found that adjuvant chemotherapy was not necessary in a large proportion of these women.

On the biomarker front, oncologists might be able to use ctDNA to guide decision-making and personalize therapy, Tolaney said. The presence of ctDNA is associated with an almost 100% likelihood of having a recurrence, whereas its absence suggests better outcomes, she explained.

Oncologists could use the presence or absence of ctDNA to guide next steps — assign patients to follow-up assessments when ctDNA is not present or to standard or experimental treatment when it is present. It may also be possible to leverage the presence of minimal residual disease to help direct treatment choices.

But ctDNA is currently not as perfect a predictor of outcome as it could be, she cautioned. “We need more sensitive assays [so] I’m not sure we’re quite ready to use lack of ctDNA to de-escalate treatment,” she said.

Dr. Tolaney declared relationships with Novartis, Pfizer, Merck, Lilly, AstraZeneca, Genentech/Roche, Eisai, Sanofi, Bristol Myers Squib, and other companies.

A version of this article appeared on Medscape.com .

Over the past few years, several new, highly effective treatment strategies have improved survival outcomes in patients with early breast cancer.

“We’ve been very fortunate” to see these advances, Sara M. Tolaney, MD, MPH, chief, Division of Breast Oncology, Dana-Farber Cancer Institute, Boston, told attendees at the European Society of Medical Oncology (ESMO) Breast Cancer annual congress.

However, Dr. Tolaney noted, these new treatment approaches can come with big limitations — namely, potential overtreatment of some patients as well as short- and long-term toxicities, some of which can be life-threatening.

These caveats have prompted trials exploring strategies to de-escalate therapy, which essentially means providing the right amount of treatment to the right patient at the right time, said Dr. Tolaney. The goal is to “right-size” or “optimize therapy” to maintain strong outcomes while mitigating side effects.

De-escalation studies are “critical to preserving quality of life” and affect the cost-effectiveness of therapy, she explained.

But, she added, de-escalation trials are “not a very attractive strategy to pharmaceutical companies” and can be challenging for researchers to conduct. These trials may, for instance, lack adequate sample sizes and sufficient statistical power, which can interfere with achieving clinically meaningful findings that may affect practice.

That is why carefully designing de-escalation trials is crucial, Dr. Tolaney said.

In her talk at ESMO Breast, Dr. Tolaney highlighted several strategies for designing these trials.

One strategy is to shorten the duration of therapy, said Dr. Tolaney.

This approach was explored in the PHARE and PERSEPHONE trials, which looked at 6 vs 12 months of trastuzumab in nonmetastatic breast cancer. Other trials, such as GeparNuevo and KEYNOTE-522, explored whether adjuvant checkpoint inhibitor therapy was needed, or could be skipped, following neoadjuvant therapy. This approach requires establishing noninferiority, or similar efficacy, between the standard of care and the shorter duration of therapy.

A second strategy is to remove part of the chemotherapy regimen, typically the most toxic agent, Dr. Tolaney continued.

Conducting a prospective, randomized trial exploring this approach in human epidermal growth factor receptor 2–positive (HER2+) early breast cancer, for example, would be difficult for a range of reasons, such as the need to enroll thousands of patients.

Dr. Tolaney and colleagues, however, designed a nonrandomized prospective study — the APT trial — with just over 400 patients to assess adjuvant paclitaxel plus trastuzumab in patients with node-negative HER2+ disease. The open-label, single-arm, phase 2 APT trial found that adjuvant paclitaxel and trastuzumab led to a 10-year recurrence-free interval of 96.3%, 10-year overall survival of 94.3%, and 10-year breast cancer–specific survival of 98.8%.

Outcomes with this adjuvant regimen were comparable to previous findings in historical controls who received doxorubicin, cyclophosphamide, paclitaxel, and trastuzumab or docetaxel, carboplatin, and trastuzumab.

Dr. Tolaney concluded that given few events, “it’s unlikely we need to escalate therapy to do better for most patients,” and the APT regimen “can be considered a reasonable and appealing approach for the majority of patients” with node-negative HER2+ breast cancer.

“A single-arm design for a de-escalation study can be practice-changing but only if there are very few recurrences,” Dr. Tolaney said.

Substituting chemotherapy with a targeted, potentially less-toxic agent is a third de-escalation approach. The ATEMPT trial compared patients receiving trastuzumab emtansine (T-DM1) with those receiving paclitaxel plus trastuzumab followed by maintenance trastuzumab.

Investigators found that de-escalation with T-DM1 was associated with very few recurrences but similar rates of certain adverse events, including grade 2 or higher neurotoxicity, febrile neutropenia, and grade 4 or higher hematologic toxicity.

However, there are questions about how to define “less toxic,” Dr. Tolaney said. The trial found, for instance, that T-DM1 did have some advantages — patients reported better quality of life and experienced less alopecia and neurotoxicity, as well as a less severe impact on fertility.

Understanding the right endpoint to demonstrate less toxicity is critical, “as we start to think about how to replace standard chemotherapies with better targeted drugs,” she added.

The ATEMPT 2.0 trial, which is currently enrolling, will aim to answer some of these questions about defining and demonstrating less toxicity, she said.

Finally, some researchers are attempting to omit chemotherapy altogether with the help of biomarkers. The TAILORx trial, for instance, aimed to stratify patients with early-stage breast cancer by clinical risk factors combined with a 21-gene expression assay and found that adjuvant chemotherapy was not necessary in a large proportion of these women.

On the biomarker front, oncologists might be able to use ctDNA to guide decision-making and personalize therapy, Tolaney said. The presence of ctDNA is associated with an almost 100% likelihood of having a recurrence, whereas its absence suggests better outcomes, she explained.

Oncologists could use the presence or absence of ctDNA to guide next steps — assign patients to follow-up assessments when ctDNA is not present or to standard or experimental treatment when it is present. It may also be possible to leverage the presence of minimal residual disease to help direct treatment choices.

But ctDNA is currently not as perfect a predictor of outcome as it could be, she cautioned. “We need more sensitive assays [so] I’m not sure we’re quite ready to use lack of ctDNA to de-escalate treatment,” she said.

Dr. Tolaney declared relationships with Novartis, Pfizer, Merck, Lilly, AstraZeneca, Genentech/Roche, Eisai, Sanofi, Bristol Myers Squib, and other companies.

A version of this article appeared on Medscape.com .

Antibody drug conjugates (ADCs) — a class of targeted medications that combine monoclonal antibodies with cytotoxic payloads — are rapidly changing the treatment landscape for patients with metastatic breast cancer.

These medications, which are designed to selectively deliver potent cytotoxic drugs to cancer cells expressing specific surface antigens such as human epidermal growth factor receptor 2 (HER2) and trophoblast cell surface antigen 2 (TROP2), can be highly effective but can also come with significant toxicities.

The latest data on several ADCs — their clinical benefit and safety — were the focus of three presentations here at the European Society for Medical Oncology (ESMO) Breast Cancer annual congress.

TROPION-Breast01

In her presentation, Komal Jhaveri, MD, of Memorial Sloan Kettering Cancer Center in New York City, reported additional safety analyses from the phase 3 TROPION-Breast01 trial looking at datopotamab deruxtecan (Dato-DXd) in patients with metastatic hormone receptor–positive (HR+)/HER2− breast cancer resistant to endocrine therapy.

Dato-DXd is an investigational ADC composed of a monoclonal antibody targeting TROP2, a transmembrane glycoprotein overexpressed in cancer cells, linked to the topoisomerase 1 inhibitor deruxtecan as the toxic payload.

As previously reported by this news organization, median progression-free survival was 6.9 months with Dato-DXd compared with 4.9 months for investigator’s choice of chemotherapy (eribulin mesylate, vinorelbine, gemcitabine, or capecitabine), which translated into a 37% (hazard ratio [HR], 0.63; P < .0001) reduction in risk for disease progression.

In addition, the rate of grade 3 or higher treatment-related adverse events with Dato-DXd was less than half that with standard chemotherapy and led to fewer dose interruptions or reductions, indicating that Dato-DXd is better tolerated.

Dr. Jhaveri focused on three treatment-related adverse events of special interest: Stomatitis/oral mucositis, ocular surface events, and adjudicated drug-related interstitial lung disease.

The rate of any grade oral mucositis with Dato-DXd was 56%, she reported. Most were grade 1 (25%) or grade 2 (23%), with only 7% grade 3. About 13% of patients had a dose reduction for oral mucositis, and only one (0.3%) patient discontinued treatment.

The median time to onset was 22 days, and median time to resolution (for events recovered/resolved at data cutoff) was 36 days.

“The study did provide toxicity management guidelines for patients who experienced stomatitis,” Dr. Jhaveri told attendees. The guidelines highly recommended daily use of a steroid-containing mouthwash as prophylaxis or, if that wasn’t available, an inert, bland mouth rinse.

“Prophylactic cryotherapy — ice chips or ice water held in the mouth throughout the infusion — was also suggested,” she said.

The overall rate of ocular surface events with Dato-DXd was 40%, with most grade 1 (32%) or grade 2 (7%), with only 0.8% grade 3. Rates of dose reduction/interruption (3.3%) and discontinuation (0.3%) were low. Most ocular events were either dry eye (22%) or keratitis (14%).

The incidence of ocular events in the chemotherapy group was 12%, higher than typically seen. The study mandated regular ocular assessments, and Jhaveri noted that it was possible that this contributed to the high rate of low-grade ocular events found in both arms.

Median time to onset of ocular events was 65 days, and median time to resolution was 67 days.

Toxicity management guidelines were also incorporated for ocular events, suggesting daily use of artificial tears and avoidance of contact lenses, Dr. Jhaveri said.

In the Dato-DXd group, there were 12 adjudicated cases (3.3%) of drug-related interstitial lung disease; most were grade 1 (1.4%) and grade 2 (1.1%).

“There was one patient who had a grade 5 event, which was characterized by the investigator as grade 3 pneumonitis, with death attributed to disease progression,” Dr. Jhaveri said. This was subsequently adjudicated to be a grade 5 drug-related death.

The median time to onset of interstitial lung disease was 84.5 days, and median time to resolution was 28 days.

Among other treatment-related adverse events of clinical interest, any grade nausea was the most common event with Dato-DXd, reported by 51% of patients, with only 1.4% grade 3 or higher.

“Prophylactic antiemetic agents are highly recommended prior to infusion of Dato-DXd and on subsequent days as needed,” Dr. Jhaveri said.

Any grade diarrhea was reported in 7.5%, with no grade 3+ diarrhea. Alopecia was reported in 36.4%, of which grade 1 was 21% and grade 2 was 15%.

Summing up, the researcher said the new safety data suggest that Dato-DXd offers “better tolerability” than standard chemotherapy. Coupled with the efficacy data, this further supports “Dato-DXd as a potential new therapeutic option for patients with previously treated, inoperable, or metastatic HR+/HER2− breast cancer.”

DESTINY-Breast02

New data from the phase 3 DESTINY-Breast02 study confirm a long-term survival benefit, as well as a favorable benefit/risk profile of trastuzumab deruxtecan in patients with HER2+ metastatic breast cancer previously treated with trastuzumab emtansine (T-DM1), reported Sung-Bae Kim, MD, PhD, with University of Ulsan College of Medicine, Seoul, Republic of Korea.

In the phase 3 randomized, multicenter, open-label clinical trial, study participants received either trastuzumab deruxtecan or physician’s choice of trastuzumab plus capecitabine or lapatinib or capecitabine. The primary results of the trial were published last year in The Lancet.

As previously reported by this news organization, after median follow-up of 21.5 months in the trastuzumab deruxtecan group and 18.6 months in the treatment of choice group, median progression-free survival was 17.8 months for trastuzumab deruxtecan vs 6.9 months for the physician’s choice group (HR, 0.36; P < .000001).

The latest data show that after a median follow-up of 30.2 months in the trastuzumab deruxtecan group and 20.5 months in the treatment of choice group, median progression-free survival was 16.7 months with trastuzumab deruxtecan vs 5.5 months with the treatment of choice — a 70% reduction in risk for progression (HR, 0.30), Dr. Kim said.

From time of randomization to progression to next line of therapy or death, median progression-free survival was 33.0 months with trastuzumab deruxtecan vs 15.0 with treatment of choice (HR, 0.42).

Median overall survival was 35.7 months with trastuzumab deruxtecan vs 25.0 months with the treatment of choice, with the risk for death reduced by 31% with trastuzumab deruxtecan (HR, 0.69).

The safety profile of trastuzumab deruxtecan continues to be “manageable, with no long-term toxicity observed with longer follow-up,” Dr. Kim told attendees. The most common treatment-emergent adverse events were nausea (73%), fatigue (62%), and vomiting (38%).

There were a total of 46 (11.4%) adjudicated drug-related interstitial lung disease/pneumonitis cases with trastuzumab deruxtecan. Most were grade 1 or 2. This risk did not increase with longer treatment duration; most events occurred within 12 months of starting treatment, Dr. Kim noted.

With longer follow-up, results of DESTINY-Breast02 “reinforce the substantial benefit” of trastuzumab deruxtecan over the treatment of physician’s choice in patients with HER2+ metastatic breast cancer previously treated with T-DM1, he concluded.

Pooled Data from TROPiCS-02 and EVER-132-002

Hope S. Rugo, MD, of the University of California San Francisco, and colleagues reported a meta-analysis of data from the phase 3 TROPiCS-02 and EVER-132-002 trials of the TROP2-directed ADC sacituzumab govitecan vs the treatment of physician’s choice in HR+/HER2− metastatic breast cancer.

In the pooled analysis, median overall survival was significantly longer with sacituzumab govitecan than with the treatment of physician’s choice in the overall population (16.2 vs 12.7 months) and in patients who received prior CDK4/6 inhibitor treatment (15.4 vs 11.5 months). Progression-free survival also favored sacituzumab govitecan.

These results are consistent with trial-level results from TROPICS-02 and EVER-132-002, reinforcing the efficacy benefits of sacituzumab govitecan over the treatment of physician’s choice, the study team said.

Evolving Landscape of ADCs in Breast Cancer

Giuseppe Curigliano, MD, PhD, with the University of Milan, Italy, who served as discussant for the TROPION-Breast01 safety analysis, noted that the clinical landscape of ADCs has “evolved over time.”

He added that despite having a similar target and similar payload, the anti-TROP2 ADCs in development for HR+/HER2− metastatic breast cancer — Dato-DXd, sacituzumab govitecan, and sacituzumab tirumotecan — appear to have different spectrums of toxicity.

Looking ahead, he said it will be important to determine whether toxicity of these agents can be predicted with a pharmacogenomic analysis and whether toxicity is related to the payload or to the linker antibody complex.

“The science and chemistry of ADCs has shown significant promise in terms of clinical activity, but we also need to better understand safety,” Dr. Curigliano told attendees.

“We need to pay attention to signals in the early phase trials of ADCs and be willing to adjust accordingly to maximize therapeutic benefit and minimize toxicity. Team science will be important in the future developmental ADCs,” he added.

TROPION-Breast01 was sponsored by AstraZeneca. DESTINY-Breast-02 was sponsored by Daiichi Sankyo. TROPiCS-02 and EVER-132-002 were supported by Gilead Sciences. Several trial investigators have disclosed various relationships with these and other pharmaceutical companies.

A version of this article appeared on Medscape.com.

Antibody drug conjugates (ADCs) — a class of targeted medications that combine monoclonal antibodies with cytotoxic payloads — are rapidly changing the treatment landscape for patients with metastatic breast cancer.

These medications, which are designed to selectively deliver potent cytotoxic drugs to cancer cells expressing specific surface antigens such as human epidermal growth factor receptor 2 (HER2) and trophoblast cell surface antigen 2 (TROP2), can be highly effective but can also come with significant toxicities.

The latest data on several ADCs — their clinical benefit and safety — were the focus of three presentations here at the European Society for Medical Oncology (ESMO) Breast Cancer annual congress.

TROPION-Breast01

In her presentation, Komal Jhaveri, MD, of Memorial Sloan Kettering Cancer Center in New York City, reported additional safety analyses from the phase 3 TROPION-Breast01 trial looking at datopotamab deruxtecan (Dato-DXd) in patients with metastatic hormone receptor–positive (HR+)/HER2− breast cancer resistant to endocrine therapy.

Dato-DXd is an investigational ADC composed of a monoclonal antibody targeting TROP2, a transmembrane glycoprotein overexpressed in cancer cells, linked to the topoisomerase 1 inhibitor deruxtecan as the toxic payload.

As previously reported by this news organization, median progression-free survival was 6.9 months with Dato-DXd compared with 4.9 months for investigator’s choice of chemotherapy (eribulin mesylate, vinorelbine, gemcitabine, or capecitabine), which translated into a 37% (hazard ratio [HR], 0.63; P < .0001) reduction in risk for disease progression.

In addition, the rate of grade 3 or higher treatment-related adverse events with Dato-DXd was less than half that with standard chemotherapy and led to fewer dose interruptions or reductions, indicating that Dato-DXd is better tolerated.

Dr. Jhaveri focused on three treatment-related adverse events of special interest: Stomatitis/oral mucositis, ocular surface events, and adjudicated drug-related interstitial lung disease.

The rate of any grade oral mucositis with Dato-DXd was 56%, she reported. Most were grade 1 (25%) or grade 2 (23%), with only 7% grade 3. About 13% of patients had a dose reduction for oral mucositis, and only one (0.3%) patient discontinued treatment.

The median time to onset was 22 days, and median time to resolution (for events recovered/resolved at data cutoff) was 36 days.

“The study did provide toxicity management guidelines for patients who experienced stomatitis,” Dr. Jhaveri told attendees. The guidelines highly recommended daily use of a steroid-containing mouthwash as prophylaxis or, if that wasn’t available, an inert, bland mouth rinse.

“Prophylactic cryotherapy — ice chips or ice water held in the mouth throughout the infusion — was also suggested,” she said.

The overall rate of ocular surface events with Dato-DXd was 40%, with most grade 1 (32%) or grade 2 (7%), with only 0.8% grade 3. Rates of dose reduction/interruption (3.3%) and discontinuation (0.3%) were low. Most ocular events were either dry eye (22%) or keratitis (14%).

The incidence of ocular events in the chemotherapy group was 12%, higher than typically seen. The study mandated regular ocular assessments, and Jhaveri noted that it was possible that this contributed to the high rate of low-grade ocular events found in both arms.

Median time to onset of ocular events was 65 days, and median time to resolution was 67 days.

Toxicity management guidelines were also incorporated for ocular events, suggesting daily use of artificial tears and avoidance of contact lenses, Dr. Jhaveri said.

In the Dato-DXd group, there were 12 adjudicated cases (3.3%) of drug-related interstitial lung disease; most were grade 1 (1.4%) and grade 2 (1.1%).

“There was one patient who had a grade 5 event, which was characterized by the investigator as grade 3 pneumonitis, with death attributed to disease progression,” Dr. Jhaveri said. This was subsequently adjudicated to be a grade 5 drug-related death.

The median time to onset of interstitial lung disease was 84.5 days, and median time to resolution was 28 days.

Among other treatment-related adverse events of clinical interest, any grade nausea was the most common event with Dato-DXd, reported by 51% of patients, with only 1.4% grade 3 or higher.

“Prophylactic antiemetic agents are highly recommended prior to infusion of Dato-DXd and on subsequent days as needed,” Dr. Jhaveri said.

Any grade diarrhea was reported in 7.5%, with no grade 3+ diarrhea. Alopecia was reported in 36.4%, of which grade 1 was 21% and grade 2 was 15%.

Summing up, the researcher said the new safety data suggest that Dato-DXd offers “better tolerability” than standard chemotherapy. Coupled with the efficacy data, this further supports “Dato-DXd as a potential new therapeutic option for patients with previously treated, inoperable, or metastatic HR+/HER2− breast cancer.”

DESTINY-Breast02

New data from the phase 3 DESTINY-Breast02 study confirm a long-term survival benefit, as well as a favorable benefit/risk profile of trastuzumab deruxtecan in patients with HER2+ metastatic breast cancer previously treated with trastuzumab emtansine (T-DM1), reported Sung-Bae Kim, MD, PhD, with University of Ulsan College of Medicine, Seoul, Republic of Korea.

In the phase 3 randomized, multicenter, open-label clinical trial, study participants received either trastuzumab deruxtecan or physician’s choice of trastuzumab plus capecitabine or lapatinib or capecitabine. The primary results of the trial were published last year in The Lancet.

As previously reported by this news organization, after median follow-up of 21.5 months in the trastuzumab deruxtecan group and 18.6 months in the treatment of choice group, median progression-free survival was 17.8 months for trastuzumab deruxtecan vs 6.9 months for the physician’s choice group (HR, 0.36; P < .000001).

The latest data show that after a median follow-up of 30.2 months in the trastuzumab deruxtecan group and 20.5 months in the treatment of choice group, median progression-free survival was 16.7 months with trastuzumab deruxtecan vs 5.5 months with the treatment of choice — a 70% reduction in risk for progression (HR, 0.30), Dr. Kim said.

From time of randomization to progression to next line of therapy or death, median progression-free survival was 33.0 months with trastuzumab deruxtecan vs 15.0 with treatment of choice (HR, 0.42).

Median overall survival was 35.7 months with trastuzumab deruxtecan vs 25.0 months with the treatment of choice, with the risk for death reduced by 31% with trastuzumab deruxtecan (HR, 0.69).

The safety profile of trastuzumab deruxtecan continues to be “manageable, with no long-term toxicity observed with longer follow-up,” Dr. Kim told attendees. The most common treatment-emergent adverse events were nausea (73%), fatigue (62%), and vomiting (38%).

There were a total of 46 (11.4%) adjudicated drug-related interstitial lung disease/pneumonitis cases with trastuzumab deruxtecan. Most were grade 1 or 2. This risk did not increase with longer treatment duration; most events occurred within 12 months of starting treatment, Dr. Kim noted.

With longer follow-up, results of DESTINY-Breast02 “reinforce the substantial benefit” of trastuzumab deruxtecan over the treatment of physician’s choice in patients with HER2+ metastatic breast cancer previously treated with T-DM1, he concluded.

Pooled Data from TROPiCS-02 and EVER-132-002

Hope S. Rugo, MD, of the University of California San Francisco, and colleagues reported a meta-analysis of data from the phase 3 TROPiCS-02 and EVER-132-002 trials of the TROP2-directed ADC sacituzumab govitecan vs the treatment of physician’s choice in HR+/HER2− metastatic breast cancer.

In the pooled analysis, median overall survival was significantly longer with sacituzumab govitecan than with the treatment of physician’s choice in the overall population (16.2 vs 12.7 months) and in patients who received prior CDK4/6 inhibitor treatment (15.4 vs 11.5 months). Progression-free survival also favored sacituzumab govitecan.

These results are consistent with trial-level results from TROPICS-02 and EVER-132-002, reinforcing the efficacy benefits of sacituzumab govitecan over the treatment of physician’s choice, the study team said.

Evolving Landscape of ADCs in Breast Cancer

Giuseppe Curigliano, MD, PhD, with the University of Milan, Italy, who served as discussant for the TROPION-Breast01 safety analysis, noted that the clinical landscape of ADCs has “evolved over time.”

He added that despite having a similar target and similar payload, the anti-TROP2 ADCs in development for HR+/HER2− metastatic breast cancer — Dato-DXd, sacituzumab govitecan, and sacituzumab tirumotecan — appear to have different spectrums of toxicity.

Looking ahead, he said it will be important to determine whether toxicity of these agents can be predicted with a pharmacogenomic analysis and whether toxicity is related to the payload or to the linker antibody complex.

“The science and chemistry of ADCs has shown significant promise in terms of clinical activity, but we also need to better understand safety,” Dr. Curigliano told attendees.

“We need to pay attention to signals in the early phase trials of ADCs and be willing to adjust accordingly to maximize therapeutic benefit and minimize toxicity. Team science will be important in the future developmental ADCs,” he added.

TROPION-Breast01 was sponsored by AstraZeneca. DESTINY-Breast-02 was sponsored by Daiichi Sankyo. TROPiCS-02 and EVER-132-002 were supported by Gilead Sciences. Several trial investigators have disclosed various relationships with these and other pharmaceutical companies.

A version of this article appeared on Medscape.com.

Antibody drug conjugates (ADCs) — a class of targeted medications that combine monoclonal antibodies with cytotoxic payloads — are rapidly changing the treatment landscape for patients with metastatic breast cancer.

These medications, which are designed to selectively deliver potent cytotoxic drugs to cancer cells expressing specific surface antigens such as human epidermal growth factor receptor 2 (HER2) and trophoblast cell surface antigen 2 (TROP2), can be highly effective but can also come with significant toxicities.

The latest data on several ADCs — their clinical benefit and safety — were the focus of three presentations here at the European Society for Medical Oncology (ESMO) Breast Cancer annual congress.

TROPION-Breast01

In her presentation, Komal Jhaveri, MD, of Memorial Sloan Kettering Cancer Center in New York City, reported additional safety analyses from the phase 3 TROPION-Breast01 trial looking at datopotamab deruxtecan (Dato-DXd) in patients with metastatic hormone receptor–positive (HR+)/HER2− breast cancer resistant to endocrine therapy.

Dato-DXd is an investigational ADC composed of a monoclonal antibody targeting TROP2, a transmembrane glycoprotein overexpressed in cancer cells, linked to the topoisomerase 1 inhibitor deruxtecan as the toxic payload.

As previously reported by this news organization, median progression-free survival was 6.9 months with Dato-DXd compared with 4.9 months for investigator’s choice of chemotherapy (eribulin mesylate, vinorelbine, gemcitabine, or capecitabine), which translated into a 37% (hazard ratio [HR], 0.63; P < .0001) reduction in risk for disease progression.

In addition, the rate of grade 3 or higher treatment-related adverse events with Dato-DXd was less than half that with standard chemotherapy and led to fewer dose interruptions or reductions, indicating that Dato-DXd is better tolerated.

Dr. Jhaveri focused on three treatment-related adverse events of special interest: Stomatitis/oral mucositis, ocular surface events, and adjudicated drug-related interstitial lung disease.

The rate of any grade oral mucositis with Dato-DXd was 56%, she reported. Most were grade 1 (25%) or grade 2 (23%), with only 7% grade 3. About 13% of patients had a dose reduction for oral mucositis, and only one (0.3%) patient discontinued treatment.

The median time to onset was 22 days, and median time to resolution (for events recovered/resolved at data cutoff) was 36 days.

“The study did provide toxicity management guidelines for patients who experienced stomatitis,” Dr. Jhaveri told attendees. The guidelines highly recommended daily use of a steroid-containing mouthwash as prophylaxis or, if that wasn’t available, an inert, bland mouth rinse.

“Prophylactic cryotherapy — ice chips or ice water held in the mouth throughout the infusion — was also suggested,” she said.

The overall rate of ocular surface events with Dato-DXd was 40%, with most grade 1 (32%) or grade 2 (7%), with only 0.8% grade 3. Rates of dose reduction/interruption (3.3%) and discontinuation (0.3%) were low. Most ocular events were either dry eye (22%) or keratitis (14%).

The incidence of ocular events in the chemotherapy group was 12%, higher than typically seen. The study mandated regular ocular assessments, and Jhaveri noted that it was possible that this contributed to the high rate of low-grade ocular events found in both arms.

Median time to onset of ocular events was 65 days, and median time to resolution was 67 days.

Toxicity management guidelines were also incorporated for ocular events, suggesting daily use of artificial tears and avoidance of contact lenses, Dr. Jhaveri said.

In the Dato-DXd group, there were 12 adjudicated cases (3.3%) of drug-related interstitial lung disease; most were grade 1 (1.4%) and grade 2 (1.1%).

“There was one patient who had a grade 5 event, which was characterized by the investigator as grade 3 pneumonitis, with death attributed to disease progression,” Dr. Jhaveri said. This was subsequently adjudicated to be a grade 5 drug-related death.

The median time to onset of interstitial lung disease was 84.5 days, and median time to resolution was 28 days.

Among other treatment-related adverse events of clinical interest, any grade nausea was the most common event with Dato-DXd, reported by 51% of patients, with only 1.4% grade 3 or higher.

“Prophylactic antiemetic agents are highly recommended prior to infusion of Dato-DXd and on subsequent days as needed,” Dr. Jhaveri said.

Any grade diarrhea was reported in 7.5%, with no grade 3+ diarrhea. Alopecia was reported in 36.4%, of which grade 1 was 21% and grade 2 was 15%.

Summing up, the researcher said the new safety data suggest that Dato-DXd offers “better tolerability” than standard chemotherapy. Coupled with the efficacy data, this further supports “Dato-DXd as a potential new therapeutic option for patients with previously treated, inoperable, or metastatic HR+/HER2− breast cancer.”

DESTINY-Breast02

New data from the phase 3 DESTINY-Breast02 study confirm a long-term survival benefit, as well as a favorable benefit/risk profile of trastuzumab deruxtecan in patients with HER2+ metastatic breast cancer previously treated with trastuzumab emtansine (T-DM1), reported Sung-Bae Kim, MD, PhD, with University of Ulsan College of Medicine, Seoul, Republic of Korea.

In the phase 3 randomized, multicenter, open-label clinical trial, study participants received either trastuzumab deruxtecan or physician’s choice of trastuzumab plus capecitabine or lapatinib or capecitabine. The primary results of the trial were published last year in The Lancet.

As previously reported by this news organization, after median follow-up of 21.5 months in the trastuzumab deruxtecan group and 18.6 months in the treatment of choice group, median progression-free survival was 17.8 months for trastuzumab deruxtecan vs 6.9 months for the physician’s choice group (HR, 0.36; P < .000001).

The latest data show that after a median follow-up of 30.2 months in the trastuzumab deruxtecan group and 20.5 months in the treatment of choice group, median progression-free survival was 16.7 months with trastuzumab deruxtecan vs 5.5 months with the treatment of choice — a 70% reduction in risk for progression (HR, 0.30), Dr. Kim said.

From time of randomization to progression to next line of therapy or death, median progression-free survival was 33.0 months with trastuzumab deruxtecan vs 15.0 with treatment of choice (HR, 0.42).

Median overall survival was 35.7 months with trastuzumab deruxtecan vs 25.0 months with the treatment of choice, with the risk for death reduced by 31% with trastuzumab deruxtecan (HR, 0.69).

The safety profile of trastuzumab deruxtecan continues to be “manageable, with no long-term toxicity observed with longer follow-up,” Dr. Kim told attendees. The most common treatment-emergent adverse events were nausea (73%), fatigue (62%), and vomiting (38%).

There were a total of 46 (11.4%) adjudicated drug-related interstitial lung disease/pneumonitis cases with trastuzumab deruxtecan. Most were grade 1 or 2. This risk did not increase with longer treatment duration; most events occurred within 12 months of starting treatment, Dr. Kim noted.

With longer follow-up, results of DESTINY-Breast02 “reinforce the substantial benefit” of trastuzumab deruxtecan over the treatment of physician’s choice in patients with HER2+ metastatic breast cancer previously treated with T-DM1, he concluded.

Pooled Data from TROPiCS-02 and EVER-132-002

Hope S. Rugo, MD, of the University of California San Francisco, and colleagues reported a meta-analysis of data from the phase 3 TROPiCS-02 and EVER-132-002 trials of the TROP2-directed ADC sacituzumab govitecan vs the treatment of physician’s choice in HR+/HER2− metastatic breast cancer.

In the pooled analysis, median overall survival was significantly longer with sacituzumab govitecan than with the treatment of physician’s choice in the overall population (16.2 vs 12.7 months) and in patients who received prior CDK4/6 inhibitor treatment (15.4 vs 11.5 months). Progression-free survival also favored sacituzumab govitecan.

These results are consistent with trial-level results from TROPICS-02 and EVER-132-002, reinforcing the efficacy benefits of sacituzumab govitecan over the treatment of physician’s choice, the study team said.

Evolving Landscape of ADCs in Breast Cancer

Giuseppe Curigliano, MD, PhD, with the University of Milan, Italy, who served as discussant for the TROPION-Breast01 safety analysis, noted that the clinical landscape of ADCs has “evolved over time.”

He added that despite having a similar target and similar payload, the anti-TROP2 ADCs in development for HR+/HER2− metastatic breast cancer — Dato-DXd, sacituzumab govitecan, and sacituzumab tirumotecan — appear to have different spectrums of toxicity.

Looking ahead, he said it will be important to determine whether toxicity of these agents can be predicted with a pharmacogenomic analysis and whether toxicity is related to the payload or to the linker antibody complex.

“The science and chemistry of ADCs has shown significant promise in terms of clinical activity, but we also need to better understand safety,” Dr. Curigliano told attendees.

“We need to pay attention to signals in the early phase trials of ADCs and be willing to adjust accordingly to maximize therapeutic benefit and minimize toxicity. Team science will be important in the future developmental ADCs,” he added.

TROPION-Breast01 was sponsored by AstraZeneca. DESTINY-Breast-02 was sponsored by Daiichi Sankyo. TROPiCS-02 and EVER-132-002 were supported by Gilead Sciences. Several trial investigators have disclosed various relationships with these and other pharmaceutical companies.

A version of this article appeared on Medscape.com.