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T-DXd Moves Toward First Line for HER2-Low Metastatic BC
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.
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.
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.
FROM ASCO
Anti-Müllerian Hormone Predicts Chemo Benefits in BC
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.
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.
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.
FROM ASCO 2024
Should ER-Low Breast Cancer Patients Be Offered Endocrine Therapy?
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.
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.
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.
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.
FROM ASCO 2024
Abemaciclib Plus Fulvestrant Improves Survival in Advanced Breast Cancer
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.
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.
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.
FROM ASCO 2024
Bariatric Surgery May Reduce Breast Cancer Risk for Some
TOPLINE:
.
METHODOLOGY:
- Previous research suggests that bariatric surgery is associated with a lower risk for cancer in people with obesity, as well as female-specific cancers in women with obesity, especially those with higher baseline insulin levels. But there is a need for large prospective studies with more detailed patient information.
- The current secondary analysis included 2867 matched women (mean age, 48 years) from a prospective nonrandomized Swedish trial, which recruited men and women who had obesity between 1987 and 2001.
- Overall, 1420 women underwent bariatric surgery, and 1447 received usual care.
- Median baseline insulin levels were 15.8 μIU/L. In the surgery group, 68.3% of patients had vertical banded gastroplasty, 18.3% underwent gastric banding, and 13.4% underwent gastric bypass.
- The main outcome was breast cancer incidence, as identified from Swedish National Cancer Registry.
TAKEAWAY:
- Over a median follow-up of 23.9 years, 66 breast cancer events occurred in the surgery group and 88 in the usual care group (P = .02).
- Bariatric surgery was associated with a 33% lower risk for breast cancer (adjusted hazard ratio [aHR], 0.67), after excluding cases that occurred within the first 3 years (to account for any undiagnosed breast cancer at baseline) and adjusting for age, body mass index, alcohol, and smoking status.
- Looking at the menopausal status at baseline, bariatric surgery was associated with a reduced risk for breast cancer in premenopausal women (aHR, 0.64) but not postmenopausal women (aHR, 0.84; 95% CI, 0.49-1.45; P = .54).
- Bariatric surgery was also associated with a lower risk for breast cancer in women with baseline insulin levels above the median (aHR, 0.55) than in those with baseline insulin levels below the median (aHR, 1.01).
IN PRACTICE:
“The surgical treatment benefit was predominantly seen in women with hyperinsulinemia, suggesting insulin may be used as a predictor of treatment effect,” the authors wrote. Authors of an accompanying editorial, however, cautioned that “it is not known if insulin levels or insulin resistance are true biomarkers of breast cancer risk in patients with obesity undergoing bariatric surgery” and urged further research into underlying biological mechanisms.
SOURCE:
This study, led by Felipe M. Kristensson, MD, from Institute of Medicine, Department of Molecular and Clinical Medicine, the Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden, was published online in JAMA Surgery. The accompanying editorial was led by Swati A. Kulkarni, MD, of the Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago.
LIMITATIONS:
The study was not randomized. Breast cancer was not a predefined outcome of the main trial. Most patients underwent vertical banded gastroplasty, which is rarely used and could limit applicability of the results; however, vertical banded gastroplasty results in weight loss similar to that observed after sleeve gastrectomy. Follow-up values for insulin and insulin resistance were not available. The researchers noted significant differences in 12 out of 17 baseline characteristics between the two groups, including a larger proportion of postmenopausal women in the usual care group.
DISCLOSURES:
This study was supported by the Swedish state, Swedish Research Council, the Health & Medical Care Committee of the Region Västra Götaland, and the Adlerbert Research Foundation. The authors did not report any conflicts of interest.
A version of this article appeared on Medscape.com.
TOPLINE:
.
METHODOLOGY:
- Previous research suggests that bariatric surgery is associated with a lower risk for cancer in people with obesity, as well as female-specific cancers in women with obesity, especially those with higher baseline insulin levels. But there is a need for large prospective studies with more detailed patient information.
- The current secondary analysis included 2867 matched women (mean age, 48 years) from a prospective nonrandomized Swedish trial, which recruited men and women who had obesity between 1987 and 2001.
- Overall, 1420 women underwent bariatric surgery, and 1447 received usual care.
- Median baseline insulin levels were 15.8 μIU/L. In the surgery group, 68.3% of patients had vertical banded gastroplasty, 18.3% underwent gastric banding, and 13.4% underwent gastric bypass.
- The main outcome was breast cancer incidence, as identified from Swedish National Cancer Registry.
TAKEAWAY:
- Over a median follow-up of 23.9 years, 66 breast cancer events occurred in the surgery group and 88 in the usual care group (P = .02).
- Bariatric surgery was associated with a 33% lower risk for breast cancer (adjusted hazard ratio [aHR], 0.67), after excluding cases that occurred within the first 3 years (to account for any undiagnosed breast cancer at baseline) and adjusting for age, body mass index, alcohol, and smoking status.
- Looking at the menopausal status at baseline, bariatric surgery was associated with a reduced risk for breast cancer in premenopausal women (aHR, 0.64) but not postmenopausal women (aHR, 0.84; 95% CI, 0.49-1.45; P = .54).
- Bariatric surgery was also associated with a lower risk for breast cancer in women with baseline insulin levels above the median (aHR, 0.55) than in those with baseline insulin levels below the median (aHR, 1.01).
IN PRACTICE:
“The surgical treatment benefit was predominantly seen in women with hyperinsulinemia, suggesting insulin may be used as a predictor of treatment effect,” the authors wrote. Authors of an accompanying editorial, however, cautioned that “it is not known if insulin levels or insulin resistance are true biomarkers of breast cancer risk in patients with obesity undergoing bariatric surgery” and urged further research into underlying biological mechanisms.
SOURCE:
This study, led by Felipe M. Kristensson, MD, from Institute of Medicine, Department of Molecular and Clinical Medicine, the Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden, was published online in JAMA Surgery. The accompanying editorial was led by Swati A. Kulkarni, MD, of the Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago.
LIMITATIONS:
The study was not randomized. Breast cancer was not a predefined outcome of the main trial. Most patients underwent vertical banded gastroplasty, which is rarely used and could limit applicability of the results; however, vertical banded gastroplasty results in weight loss similar to that observed after sleeve gastrectomy. Follow-up values for insulin and insulin resistance were not available. The researchers noted significant differences in 12 out of 17 baseline characteristics between the two groups, including a larger proportion of postmenopausal women in the usual care group.
DISCLOSURES:
This study was supported by the Swedish state, Swedish Research Council, the Health & Medical Care Committee of the Region Västra Götaland, and the Adlerbert Research Foundation. The authors did not report any conflicts of interest.
A version of this article appeared on Medscape.com.
TOPLINE:
.
METHODOLOGY:
- Previous research suggests that bariatric surgery is associated with a lower risk for cancer in people with obesity, as well as female-specific cancers in women with obesity, especially those with higher baseline insulin levels. But there is a need for large prospective studies with more detailed patient information.
- The current secondary analysis included 2867 matched women (mean age, 48 years) from a prospective nonrandomized Swedish trial, which recruited men and women who had obesity between 1987 and 2001.
- Overall, 1420 women underwent bariatric surgery, and 1447 received usual care.
- Median baseline insulin levels were 15.8 μIU/L. In the surgery group, 68.3% of patients had vertical banded gastroplasty, 18.3% underwent gastric banding, and 13.4% underwent gastric bypass.
- The main outcome was breast cancer incidence, as identified from Swedish National Cancer Registry.
TAKEAWAY:
- Over a median follow-up of 23.9 years, 66 breast cancer events occurred in the surgery group and 88 in the usual care group (P = .02).
- Bariatric surgery was associated with a 33% lower risk for breast cancer (adjusted hazard ratio [aHR], 0.67), after excluding cases that occurred within the first 3 years (to account for any undiagnosed breast cancer at baseline) and adjusting for age, body mass index, alcohol, and smoking status.
- Looking at the menopausal status at baseline, bariatric surgery was associated with a reduced risk for breast cancer in premenopausal women (aHR, 0.64) but not postmenopausal women (aHR, 0.84; 95% CI, 0.49-1.45; P = .54).
- Bariatric surgery was also associated with a lower risk for breast cancer in women with baseline insulin levels above the median (aHR, 0.55) than in those with baseline insulin levels below the median (aHR, 1.01).
IN PRACTICE:
“The surgical treatment benefit was predominantly seen in women with hyperinsulinemia, suggesting insulin may be used as a predictor of treatment effect,” the authors wrote. Authors of an accompanying editorial, however, cautioned that “it is not known if insulin levels or insulin resistance are true biomarkers of breast cancer risk in patients with obesity undergoing bariatric surgery” and urged further research into underlying biological mechanisms.
SOURCE:
This study, led by Felipe M. Kristensson, MD, from Institute of Medicine, Department of Molecular and Clinical Medicine, the Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden, was published online in JAMA Surgery. The accompanying editorial was led by Swati A. Kulkarni, MD, of the Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago.
LIMITATIONS:
The study was not randomized. Breast cancer was not a predefined outcome of the main trial. Most patients underwent vertical banded gastroplasty, which is rarely used and could limit applicability of the results; however, vertical banded gastroplasty results in weight loss similar to that observed after sleeve gastrectomy. Follow-up values for insulin and insulin resistance were not available. The researchers noted significant differences in 12 out of 17 baseline characteristics between the two groups, including a larger proportion of postmenopausal women in the usual care group.
DISCLOSURES:
This study was supported by the Swedish state, Swedish Research Council, the Health & Medical Care Committee of the Region Västra Götaland, and the Adlerbert Research Foundation. The authors did not report any conflicts of interest.
A version of this article appeared on Medscape.com.
Carefully Designing De-escalation Trials in Breast Cancer
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.
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.
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.
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 .
FROM ESMO BREAST CANCER 2024
ADCs for Breast Cancer: Clear Benefits, Manageable Risks
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.
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.
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.
FROM ESMO BREAST CANCER 2024
The ASCO Annual Meeting Starts This Week
From its origins in 1964, ASCO’s annual event has grown to become the world’s largest clinical oncology meeting, drawing attendees from across the globe.
More than 7000 abstracts were submitted for this year’s meeting a new record — and over 5000 were selected for presentation.
This year’s chair of the Annual Meeting Education Committee, Thomas William LeBlanc, MD, told us he has been attending the meeting since his training days more than a decade ago.
The event is “just incredibly empowering and energizing,” Dr. LeBlanc said, with opportunities to catch up with old colleagues and meet new ones, learn how far oncology has come and where it’s headed, and hear clinical pearls to take back the clinic.
This year’s theme, selected by ASCO President Lynn M. Schuchter, MD, is “The Art and Science of Cancer Care: From Comfort to Cure.”
Dr. LeBlanc, a blood cancer specialist at Duke University, Durham, North Carolina, said the theme has been woven throughout the abstract and educational sessions. Most sessions will have at least one presentation related to how we support people — not only “when we cure them but also when we can’t cure them,” he said.
Topics will include patient well-being, comfort measures, and survivorship. And for the first time the plenary session will include a palliative care abstract that addresses whether or not palliative care can be delivered effectively through telemedicine. The session is on Sunday, June 2.
Other potentially practice changing plenary abstracts tackle immunotherapy combinations for resectable melanoma, perioperative chemotherapy vs neoadjuvant chemoradiation for esophageal cancer, and osimertinib after definitive chemoradiotherapy for unresectable non–small cell lung cancer.
ASCO is piloting a slightly different format for research presentations this year. Instead of starting with context and background, speakers have been asked to present study results upfront as well as repeat them at the end of the talk. The reason behind the tweak is that engagement and retention tend to be better when results are presented upfront, instead of just at the end of a talk.
A popular session — ASCO Voices — has also been given a more central position in the conference: Friday, May 31. In this session, speakers will give short presentations about their personal experiences as providers, researchers, or patients.
ASCO Voices is a relatively recent addition to the meeting that has grown and gotten better. The talks are usually “very powerful narratives” that remind clinicians about “the importance of what they’re doing each day,” Dr. LeBlanc said.
Snippets of the talks will be played while people wait for sessions to begin at the meeting, so attendees who miss the Friday talks can still hear them.
In terms of educational sessions, Dr. LeBlanc highlighted two that might be of general interest to practicing oncologists: A joint ASCO/American Association for Cancer Research session entitled “Drugging the ‘Undruggable’ Target: Successes, Challenges, and the Road Ahead,” on Sunday morning and “Common Sense Oncology: Equity, Value, and Outcomes That Matter” on Monday morning.
As a blood cancer specialist, he said he is particularly interested in the topline results from the ASC4FIRST trial of asciminib, a newer kinase inhibitor, in newly diagnosed chronic myeloid leukemia, presented on Friday.
As in past years, this news organization will be on hand providing coverage with a dedicated team of reporters, editors, and videographers. Stop by our exhibit hall booth — number 26030 — to learn about the tools we offer to support your practice.
A version of this article appeared on Medscape.com .
From its origins in 1964, ASCO’s annual event has grown to become the world’s largest clinical oncology meeting, drawing attendees from across the globe.
More than 7000 abstracts were submitted for this year’s meeting a new record — and over 5000 were selected for presentation.
This year’s chair of the Annual Meeting Education Committee, Thomas William LeBlanc, MD, told us he has been attending the meeting since his training days more than a decade ago.
The event is “just incredibly empowering and energizing,” Dr. LeBlanc said, with opportunities to catch up with old colleagues and meet new ones, learn how far oncology has come and where it’s headed, and hear clinical pearls to take back the clinic.
This year’s theme, selected by ASCO President Lynn M. Schuchter, MD, is “The Art and Science of Cancer Care: From Comfort to Cure.”
Dr. LeBlanc, a blood cancer specialist at Duke University, Durham, North Carolina, said the theme has been woven throughout the abstract and educational sessions. Most sessions will have at least one presentation related to how we support people — not only “when we cure them but also when we can’t cure them,” he said.
Topics will include patient well-being, comfort measures, and survivorship. And for the first time the plenary session will include a palliative care abstract that addresses whether or not palliative care can be delivered effectively through telemedicine. The session is on Sunday, June 2.
Other potentially practice changing plenary abstracts tackle immunotherapy combinations for resectable melanoma, perioperative chemotherapy vs neoadjuvant chemoradiation for esophageal cancer, and osimertinib after definitive chemoradiotherapy for unresectable non–small cell lung cancer.
ASCO is piloting a slightly different format for research presentations this year. Instead of starting with context and background, speakers have been asked to present study results upfront as well as repeat them at the end of the talk. The reason behind the tweak is that engagement and retention tend to be better when results are presented upfront, instead of just at the end of a talk.
A popular session — ASCO Voices — has also been given a more central position in the conference: Friday, May 31. In this session, speakers will give short presentations about their personal experiences as providers, researchers, or patients.
ASCO Voices is a relatively recent addition to the meeting that has grown and gotten better. The talks are usually “very powerful narratives” that remind clinicians about “the importance of what they’re doing each day,” Dr. LeBlanc said.
Snippets of the talks will be played while people wait for sessions to begin at the meeting, so attendees who miss the Friday talks can still hear them.
In terms of educational sessions, Dr. LeBlanc highlighted two that might be of general interest to practicing oncologists: A joint ASCO/American Association for Cancer Research session entitled “Drugging the ‘Undruggable’ Target: Successes, Challenges, and the Road Ahead,” on Sunday morning and “Common Sense Oncology: Equity, Value, and Outcomes That Matter” on Monday morning.
As a blood cancer specialist, he said he is particularly interested in the topline results from the ASC4FIRST trial of asciminib, a newer kinase inhibitor, in newly diagnosed chronic myeloid leukemia, presented on Friday.
As in past years, this news organization will be on hand providing coverage with a dedicated team of reporters, editors, and videographers. Stop by our exhibit hall booth — number 26030 — to learn about the tools we offer to support your practice.
A version of this article appeared on Medscape.com .
From its origins in 1964, ASCO’s annual event has grown to become the world’s largest clinical oncology meeting, drawing attendees from across the globe.
More than 7000 abstracts were submitted for this year’s meeting a new record — and over 5000 were selected for presentation.
This year’s chair of the Annual Meeting Education Committee, Thomas William LeBlanc, MD, told us he has been attending the meeting since his training days more than a decade ago.
The event is “just incredibly empowering and energizing,” Dr. LeBlanc said, with opportunities to catch up with old colleagues and meet new ones, learn how far oncology has come and where it’s headed, and hear clinical pearls to take back the clinic.
This year’s theme, selected by ASCO President Lynn M. Schuchter, MD, is “The Art and Science of Cancer Care: From Comfort to Cure.”
Dr. LeBlanc, a blood cancer specialist at Duke University, Durham, North Carolina, said the theme has been woven throughout the abstract and educational sessions. Most sessions will have at least one presentation related to how we support people — not only “when we cure them but also when we can’t cure them,” he said.
Topics will include patient well-being, comfort measures, and survivorship. And for the first time the plenary session will include a palliative care abstract that addresses whether or not palliative care can be delivered effectively through telemedicine. The session is on Sunday, June 2.
Other potentially practice changing plenary abstracts tackle immunotherapy combinations for resectable melanoma, perioperative chemotherapy vs neoadjuvant chemoradiation for esophageal cancer, and osimertinib after definitive chemoradiotherapy for unresectable non–small cell lung cancer.
ASCO is piloting a slightly different format for research presentations this year. Instead of starting with context and background, speakers have been asked to present study results upfront as well as repeat them at the end of the talk. The reason behind the tweak is that engagement and retention tend to be better when results are presented upfront, instead of just at the end of a talk.
A popular session — ASCO Voices — has also been given a more central position in the conference: Friday, May 31. In this session, speakers will give short presentations about their personal experiences as providers, researchers, or patients.
ASCO Voices is a relatively recent addition to the meeting that has grown and gotten better. The talks are usually “very powerful narratives” that remind clinicians about “the importance of what they’re doing each day,” Dr. LeBlanc said.
Snippets of the talks will be played while people wait for sessions to begin at the meeting, so attendees who miss the Friday talks can still hear them.
In terms of educational sessions, Dr. LeBlanc highlighted two that might be of general interest to practicing oncologists: A joint ASCO/American Association for Cancer Research session entitled “Drugging the ‘Undruggable’ Target: Successes, Challenges, and the Road Ahead,” on Sunday morning and “Common Sense Oncology: Equity, Value, and Outcomes That Matter” on Monday morning.
As a blood cancer specialist, he said he is particularly interested in the topline results from the ASC4FIRST trial of asciminib, a newer kinase inhibitor, in newly diagnosed chronic myeloid leukemia, presented on Friday.
As in past years, this news organization will be on hand providing coverage with a dedicated team of reporters, editors, and videographers. Stop by our exhibit hall booth — number 26030 — to learn about the tools we offer to support your practice.
A version of this article appeared on Medscape.com .
Exercise Improves Sexual Health in Women With Metastatic Breast Cancer
TOPLINE:
, as well as fatigue and overall quality of life in women with metastatic breast cancer, a randomized controlled trial found.
METHODOLOGY:
- Patients with metastatic breast cancer often experience issues with sexual health. Data on the effectiveness of interventions such as exercise are lacking.
- The PREFERABLE-EFFECT trial enrolled 355 women (mean age, 55.4 years) with metastatic breast cancer; 75% had received first- or second-line treatment at enrollment, and 68% had bone metastases.
- Trial participants were randomly allocated to either usual care or a 9-month (twice weekly) supervised exercise program combining aerobic, resistance, and balance exercises. All participants received general exercise advice and an activity tracker.
- Patients were assessed at baseline and 3, 6, and 9 months. Exercise intervention effects were analyzed on an intent-to-treat basis with mixed models.
TAKEAWAY:
- At baseline, most women showed no interest in sexual activity, and 60% were not sexually active. Nearly half (46%) of sexually active women reported no or little sexual enjoyment. Low sexual function was associated with depression and older age.
- Among patients receiving endocrine therapy, 27% reported vaginal pain and 40% reported vaginal dryness during sexual activity.
- The exercise intervention significantly improved sexual functioning (effect size = 0.28; P = .003) and endocrine sexual symptoms (effect size = 0.25; P = .003) at 6 months, and these effects were sustained at 9 months. Sexual enjoyment also appeared to improve in the exercise group, but due to the small sample size, this was not a statistically significant effect.
- Prior results from the trial showed that the exercise program had significant benefits for fatigue and overall quality of life (primary outcomes).
IN PRACTICE:
Patients with metastatic breast cancer “often suffer from sexual health issues and this topic should be addressed by clinicians,” said study presenter Martina Schmidt, PhD, with the German Cancer Research Center, Heidelberg.
“Physical exercise should be a crucial component of the prescription we offer to our patients,” said study discussant Matteo Lambertini, MD, PhD, with University of Genova, Genova, Italy.
SOURCE:
The research (abstract 269MO) was presented at the European Society for Medical Oncology Breast Cancer 2024 Annual Congress.
LIMITATIONS:
Further research needs to be done to determine the optimal role of exercise in addressing symptom burden.
DISCLOSURES:
This research was funded by the European Union’s Horizon 2020 research and innovation program and the National Health and Medical Research Council of Australia. Dr. Schmidt has no relevant conflicts of interest. Dr. Lambertini has financial relationships with various pharmaceutical companies including Roche, Novartis, AstraZeneca, Lilly, Exact Sciences, Pfizer, and others.
A version of this article appeared on Medscape.com.
TOPLINE:
, as well as fatigue and overall quality of life in women with metastatic breast cancer, a randomized controlled trial found.
METHODOLOGY:
- Patients with metastatic breast cancer often experience issues with sexual health. Data on the effectiveness of interventions such as exercise are lacking.
- The PREFERABLE-EFFECT trial enrolled 355 women (mean age, 55.4 years) with metastatic breast cancer; 75% had received first- or second-line treatment at enrollment, and 68% had bone metastases.
- Trial participants were randomly allocated to either usual care or a 9-month (twice weekly) supervised exercise program combining aerobic, resistance, and balance exercises. All participants received general exercise advice and an activity tracker.
- Patients were assessed at baseline and 3, 6, and 9 months. Exercise intervention effects were analyzed on an intent-to-treat basis with mixed models.
TAKEAWAY:
- At baseline, most women showed no interest in sexual activity, and 60% were not sexually active. Nearly half (46%) of sexually active women reported no or little sexual enjoyment. Low sexual function was associated with depression and older age.
- Among patients receiving endocrine therapy, 27% reported vaginal pain and 40% reported vaginal dryness during sexual activity.
- The exercise intervention significantly improved sexual functioning (effect size = 0.28; P = .003) and endocrine sexual symptoms (effect size = 0.25; P = .003) at 6 months, and these effects were sustained at 9 months. Sexual enjoyment also appeared to improve in the exercise group, but due to the small sample size, this was not a statistically significant effect.
- Prior results from the trial showed that the exercise program had significant benefits for fatigue and overall quality of life (primary outcomes).
IN PRACTICE:
Patients with metastatic breast cancer “often suffer from sexual health issues and this topic should be addressed by clinicians,” said study presenter Martina Schmidt, PhD, with the German Cancer Research Center, Heidelberg.
“Physical exercise should be a crucial component of the prescription we offer to our patients,” said study discussant Matteo Lambertini, MD, PhD, with University of Genova, Genova, Italy.
SOURCE:
The research (abstract 269MO) was presented at the European Society for Medical Oncology Breast Cancer 2024 Annual Congress.
LIMITATIONS:
Further research needs to be done to determine the optimal role of exercise in addressing symptom burden.
DISCLOSURES:
This research was funded by the European Union’s Horizon 2020 research and innovation program and the National Health and Medical Research Council of Australia. Dr. Schmidt has no relevant conflicts of interest. Dr. Lambertini has financial relationships with various pharmaceutical companies including Roche, Novartis, AstraZeneca, Lilly, Exact Sciences, Pfizer, and others.
A version of this article appeared on Medscape.com.
TOPLINE:
, as well as fatigue and overall quality of life in women with metastatic breast cancer, a randomized controlled trial found.
METHODOLOGY:
- Patients with metastatic breast cancer often experience issues with sexual health. Data on the effectiveness of interventions such as exercise are lacking.
- The PREFERABLE-EFFECT trial enrolled 355 women (mean age, 55.4 years) with metastatic breast cancer; 75% had received first- or second-line treatment at enrollment, and 68% had bone metastases.
- Trial participants were randomly allocated to either usual care or a 9-month (twice weekly) supervised exercise program combining aerobic, resistance, and balance exercises. All participants received general exercise advice and an activity tracker.
- Patients were assessed at baseline and 3, 6, and 9 months. Exercise intervention effects were analyzed on an intent-to-treat basis with mixed models.
TAKEAWAY:
- At baseline, most women showed no interest in sexual activity, and 60% were not sexually active. Nearly half (46%) of sexually active women reported no or little sexual enjoyment. Low sexual function was associated with depression and older age.
- Among patients receiving endocrine therapy, 27% reported vaginal pain and 40% reported vaginal dryness during sexual activity.
- The exercise intervention significantly improved sexual functioning (effect size = 0.28; P = .003) and endocrine sexual symptoms (effect size = 0.25; P = .003) at 6 months, and these effects were sustained at 9 months. Sexual enjoyment also appeared to improve in the exercise group, but due to the small sample size, this was not a statistically significant effect.
- Prior results from the trial showed that the exercise program had significant benefits for fatigue and overall quality of life (primary outcomes).
IN PRACTICE:
Patients with metastatic breast cancer “often suffer from sexual health issues and this topic should be addressed by clinicians,” said study presenter Martina Schmidt, PhD, with the German Cancer Research Center, Heidelberg.
“Physical exercise should be a crucial component of the prescription we offer to our patients,” said study discussant Matteo Lambertini, MD, PhD, with University of Genova, Genova, Italy.
SOURCE:
The research (abstract 269MO) was presented at the European Society for Medical Oncology Breast Cancer 2024 Annual Congress.
LIMITATIONS:
Further research needs to be done to determine the optimal role of exercise in addressing symptom burden.
DISCLOSURES:
This research was funded by the European Union’s Horizon 2020 research and innovation program and the National Health and Medical Research Council of Australia. Dr. Schmidt has no relevant conflicts of interest. Dr. Lambertini has financial relationships with various pharmaceutical companies including Roche, Novartis, AstraZeneca, Lilly, Exact Sciences, Pfizer, and others.
A version of this article appeared on Medscape.com.
ASTRO Releases New EBRT Guideline for Symptomatic Bone Mets
The guideline was needed to update previous recommendations and incorporate new high-quality evidence for the management of symptomatic bone metastases, Sara Alcorn, MD, PhD, of the University of Minnesota, Minneapolis, and colleagues wrote in Practical Radiation Oncology.
The focus was on the efficacy of EBRT in reducing pain, improving skeletal function, and enhancing quality of life, they wrote in the clinical practice guideline.
In developing their recommendations, the ASTRO task force reviewed evidence from 53 randomized controlled trials (RCTs) and 31 nonrandomized studies, and considered clinical experience.
Indications for Palliative Radiation
EBRT is strongly recommended for reducing pain from osseous metastasis and improving ambulatory status, sphincter function, and reducing pain in patients with spinal metastases causing compression of the spinal cord or cauda equina.
For patients with symptomatic bone metastases and an anticipated life expectancy of at least 4 weeks, EBRT is conditionally recommended to improve quality of life.
Implementation of other Treatments Alongside Palliative Radiation
Instead of RT alone, surgery with postoperative RT is conditionally recommended for patients with compression of the spinal cord or cauda equina.
Postoperative RT is strongly recommended for patients who have undergone surgery for non-spine bone metastases or spine metastases without involving spinal cord or cauda equina compression.
For patients with spinal bone metastases compressing the spinal cord or cauda equina, combining RT with dexamethasone is strongly recommended over RT alone.
Techniques, Dose-Fractionation, and Dose-Constraints for Initial Palliative Radiation
For patients with symptomatic bone metastases undergoing conventional palliative RT, strongly recommended doses are 800 cGy in 1 fraction, 2000 cGy in 5 fractions, 2400 cGy in 6 fractions, or 3000 cGy in 10 fractions.
For patients with spinal bone metastases causing compression of the spinal cord or cauda equina who are not candidates for initial surgical decompression and are treated with conventional palliative RT, strongly recommended doses are 800 cGy in 1 fraction, 1600 cGy in 2 fractions, 2000 cGy in 5 fractions, or 3000 cGy in 10 fractions.
When selecting dose-fractionation, consider patient and disease factors such as prognosis and radiosensitivity, the authors wrote.
Highly conformal planning and delivery techniques, such as intensity-modulated radiation therapy, are conditionally recommended for patients with spinal bone metastases compressing the spinal cord or cauda equina who are receiving dose-escalated palliative RT.
The strongly recommended stereotactic body radiotherapy (SBRT) doses for patients with symptomatic bone metastases are 1200 to 1600 cGy in 1 fraction for non-spine metastases and 2400 cGy in 2 fractions for spine metastases. Other established SBRT dose and fractionation regimens with similar biologically effective doses may be considered based on patient tumor characteristics, normal tissue factors, and physician experience.
For patients with symptomatic bone metastases who have an ECOG PS of 0-2, are not undergoing surgical intervention, and have no neurological symptoms, SBRT is conditionally recommended over conventional palliative RT. Other factors to consider include life expectancy, tumor radiosensitivity, and metastatic disease burden, the guideline says.
Techniques, Dose-Fractionation, and Dose-Constraints for Palliative Reirradiation
For patients with spinal bone metastases requiring reirradiation to the same site, the strongly recommended conventional palliative RT regimens are 800 cGy in 1 fraction, 2000 cGy in 5 fractions, 2400 cGy in 6 fractions, or 2000 cGy in 8 fractions. When determining the RT dose-fractionation, consider the prior RT dose, time interval, and total spinal cord tolerance, the guideline says.
Treatment with SBRT is conditionally recommended for patients with spinal bone metastases needing reirradiation at the same site. When determining if SBRT is appropriate, consider patient factors such as urgency of treatment, prognosis, and radio-resistance. In addition, consider the prior RT dose, time interval, and total spinal cord tolerance when determining the RT dose-fractionation, the authors say.
The strongly recommended options for patients with symptomatic non-spine bone metastases needing reirradiation at the same site are single-fraction RT (800 cGy in 1 fraction) or multifraction conventional palliative RT (2000 cGy in 5 fractions or 2400 cGy in 6 fractions).
Impact of Techniques and Dose-fractionation on Quality of Life and Toxicity
For patients with bone metastases undergoing palliative radiation, it is strongly recommended to use a shared decision-making approach to determine the dose, fractionation, and supportive measures to optimize quality of life.
“Based on published data, the ASTRO task force’s recommendations inform best clinical practices on palliative RT for symptomatic bone metastases,” the guideline panelists said.
Limitations
While the guideline provides comprehensive recommendations, the panelists underscored the importance of individualized treatment approaches. Future research is needed to address gaps in evidence, particularly regarding advanced RT techniques and reirradiation strategies.
Guideline development was funded by ASTRO, with the systematic evidence review funded by the Patient-Centered Outcomes Research Institute. The panelists disclosed relationships with AstraZeneca, Elekta, Teladoc, and others.
The guideline was needed to update previous recommendations and incorporate new high-quality evidence for the management of symptomatic bone metastases, Sara Alcorn, MD, PhD, of the University of Minnesota, Minneapolis, and colleagues wrote in Practical Radiation Oncology.
The focus was on the efficacy of EBRT in reducing pain, improving skeletal function, and enhancing quality of life, they wrote in the clinical practice guideline.
In developing their recommendations, the ASTRO task force reviewed evidence from 53 randomized controlled trials (RCTs) and 31 nonrandomized studies, and considered clinical experience.
Indications for Palliative Radiation
EBRT is strongly recommended for reducing pain from osseous metastasis and improving ambulatory status, sphincter function, and reducing pain in patients with spinal metastases causing compression of the spinal cord or cauda equina.
For patients with symptomatic bone metastases and an anticipated life expectancy of at least 4 weeks, EBRT is conditionally recommended to improve quality of life.
Implementation of other Treatments Alongside Palliative Radiation
Instead of RT alone, surgery with postoperative RT is conditionally recommended for patients with compression of the spinal cord or cauda equina.
Postoperative RT is strongly recommended for patients who have undergone surgery for non-spine bone metastases or spine metastases without involving spinal cord or cauda equina compression.
For patients with spinal bone metastases compressing the spinal cord or cauda equina, combining RT with dexamethasone is strongly recommended over RT alone.
Techniques, Dose-Fractionation, and Dose-Constraints for Initial Palliative Radiation
For patients with symptomatic bone metastases undergoing conventional palliative RT, strongly recommended doses are 800 cGy in 1 fraction, 2000 cGy in 5 fractions, 2400 cGy in 6 fractions, or 3000 cGy in 10 fractions.
For patients with spinal bone metastases causing compression of the spinal cord or cauda equina who are not candidates for initial surgical decompression and are treated with conventional palliative RT, strongly recommended doses are 800 cGy in 1 fraction, 1600 cGy in 2 fractions, 2000 cGy in 5 fractions, or 3000 cGy in 10 fractions.
When selecting dose-fractionation, consider patient and disease factors such as prognosis and radiosensitivity, the authors wrote.
Highly conformal planning and delivery techniques, such as intensity-modulated radiation therapy, are conditionally recommended for patients with spinal bone metastases compressing the spinal cord or cauda equina who are receiving dose-escalated palliative RT.
The strongly recommended stereotactic body radiotherapy (SBRT) doses for patients with symptomatic bone metastases are 1200 to 1600 cGy in 1 fraction for non-spine metastases and 2400 cGy in 2 fractions for spine metastases. Other established SBRT dose and fractionation regimens with similar biologically effective doses may be considered based on patient tumor characteristics, normal tissue factors, and physician experience.
For patients with symptomatic bone metastases who have an ECOG PS of 0-2, are not undergoing surgical intervention, and have no neurological symptoms, SBRT is conditionally recommended over conventional palliative RT. Other factors to consider include life expectancy, tumor radiosensitivity, and metastatic disease burden, the guideline says.
Techniques, Dose-Fractionation, and Dose-Constraints for Palliative Reirradiation
For patients with spinal bone metastases requiring reirradiation to the same site, the strongly recommended conventional palliative RT regimens are 800 cGy in 1 fraction, 2000 cGy in 5 fractions, 2400 cGy in 6 fractions, or 2000 cGy in 8 fractions. When determining the RT dose-fractionation, consider the prior RT dose, time interval, and total spinal cord tolerance, the guideline says.
Treatment with SBRT is conditionally recommended for patients with spinal bone metastases needing reirradiation at the same site. When determining if SBRT is appropriate, consider patient factors such as urgency of treatment, prognosis, and radio-resistance. In addition, consider the prior RT dose, time interval, and total spinal cord tolerance when determining the RT dose-fractionation, the authors say.
The strongly recommended options for patients with symptomatic non-spine bone metastases needing reirradiation at the same site are single-fraction RT (800 cGy in 1 fraction) or multifraction conventional palliative RT (2000 cGy in 5 fractions or 2400 cGy in 6 fractions).
Impact of Techniques and Dose-fractionation on Quality of Life and Toxicity
For patients with bone metastases undergoing palliative radiation, it is strongly recommended to use a shared decision-making approach to determine the dose, fractionation, and supportive measures to optimize quality of life.
“Based on published data, the ASTRO task force’s recommendations inform best clinical practices on palliative RT for symptomatic bone metastases,” the guideline panelists said.
Limitations
While the guideline provides comprehensive recommendations, the panelists underscored the importance of individualized treatment approaches. Future research is needed to address gaps in evidence, particularly regarding advanced RT techniques and reirradiation strategies.
Guideline development was funded by ASTRO, with the systematic evidence review funded by the Patient-Centered Outcomes Research Institute. The panelists disclosed relationships with AstraZeneca, Elekta, Teladoc, and others.
The guideline was needed to update previous recommendations and incorporate new high-quality evidence for the management of symptomatic bone metastases, Sara Alcorn, MD, PhD, of the University of Minnesota, Minneapolis, and colleagues wrote in Practical Radiation Oncology.
The focus was on the efficacy of EBRT in reducing pain, improving skeletal function, and enhancing quality of life, they wrote in the clinical practice guideline.
In developing their recommendations, the ASTRO task force reviewed evidence from 53 randomized controlled trials (RCTs) and 31 nonrandomized studies, and considered clinical experience.
Indications for Palliative Radiation
EBRT is strongly recommended for reducing pain from osseous metastasis and improving ambulatory status, sphincter function, and reducing pain in patients with spinal metastases causing compression of the spinal cord or cauda equina.
For patients with symptomatic bone metastases and an anticipated life expectancy of at least 4 weeks, EBRT is conditionally recommended to improve quality of life.
Implementation of other Treatments Alongside Palliative Radiation
Instead of RT alone, surgery with postoperative RT is conditionally recommended for patients with compression of the spinal cord or cauda equina.
Postoperative RT is strongly recommended for patients who have undergone surgery for non-spine bone metastases or spine metastases without involving spinal cord or cauda equina compression.
For patients with spinal bone metastases compressing the spinal cord or cauda equina, combining RT with dexamethasone is strongly recommended over RT alone.
Techniques, Dose-Fractionation, and Dose-Constraints for Initial Palliative Radiation
For patients with symptomatic bone metastases undergoing conventional palliative RT, strongly recommended doses are 800 cGy in 1 fraction, 2000 cGy in 5 fractions, 2400 cGy in 6 fractions, or 3000 cGy in 10 fractions.
For patients with spinal bone metastases causing compression of the spinal cord or cauda equina who are not candidates for initial surgical decompression and are treated with conventional palliative RT, strongly recommended doses are 800 cGy in 1 fraction, 1600 cGy in 2 fractions, 2000 cGy in 5 fractions, or 3000 cGy in 10 fractions.
When selecting dose-fractionation, consider patient and disease factors such as prognosis and radiosensitivity, the authors wrote.
Highly conformal planning and delivery techniques, such as intensity-modulated radiation therapy, are conditionally recommended for patients with spinal bone metastases compressing the spinal cord or cauda equina who are receiving dose-escalated palliative RT.
The strongly recommended stereotactic body radiotherapy (SBRT) doses for patients with symptomatic bone metastases are 1200 to 1600 cGy in 1 fraction for non-spine metastases and 2400 cGy in 2 fractions for spine metastases. Other established SBRT dose and fractionation regimens with similar biologically effective doses may be considered based on patient tumor characteristics, normal tissue factors, and physician experience.
For patients with symptomatic bone metastases who have an ECOG PS of 0-2, are not undergoing surgical intervention, and have no neurological symptoms, SBRT is conditionally recommended over conventional palliative RT. Other factors to consider include life expectancy, tumor radiosensitivity, and metastatic disease burden, the guideline says.
Techniques, Dose-Fractionation, and Dose-Constraints for Palliative Reirradiation
For patients with spinal bone metastases requiring reirradiation to the same site, the strongly recommended conventional palliative RT regimens are 800 cGy in 1 fraction, 2000 cGy in 5 fractions, 2400 cGy in 6 fractions, or 2000 cGy in 8 fractions. When determining the RT dose-fractionation, consider the prior RT dose, time interval, and total spinal cord tolerance, the guideline says.
Treatment with SBRT is conditionally recommended for patients with spinal bone metastases needing reirradiation at the same site. When determining if SBRT is appropriate, consider patient factors such as urgency of treatment, prognosis, and radio-resistance. In addition, consider the prior RT dose, time interval, and total spinal cord tolerance when determining the RT dose-fractionation, the authors say.
The strongly recommended options for patients with symptomatic non-spine bone metastases needing reirradiation at the same site are single-fraction RT (800 cGy in 1 fraction) or multifraction conventional palliative RT (2000 cGy in 5 fractions or 2400 cGy in 6 fractions).
Impact of Techniques and Dose-fractionation on Quality of Life and Toxicity
For patients with bone metastases undergoing palliative radiation, it is strongly recommended to use a shared decision-making approach to determine the dose, fractionation, and supportive measures to optimize quality of life.
“Based on published data, the ASTRO task force’s recommendations inform best clinical practices on palliative RT for symptomatic bone metastases,” the guideline panelists said.
Limitations
While the guideline provides comprehensive recommendations, the panelists underscored the importance of individualized treatment approaches. Future research is needed to address gaps in evidence, particularly regarding advanced RT techniques and reirradiation strategies.
Guideline development was funded by ASTRO, with the systematic evidence review funded by the Patient-Centered Outcomes Research Institute. The panelists disclosed relationships with AstraZeneca, Elekta, Teladoc, and others.
FROM PRACTICAL RADIATION ONCOLOGY