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LBCL: CAR T Benefits Both Young and Old
“This real-world study demonstrates that CD19 CAR-T cell therapy is feasible in a population of patients aged 75 years and older,” said senior author Pierre Bories, MD, PhD, of the Institute for Cancer Strasbourg-Europe, in Alsace, France. He presented the findings at the annual meeting of the European Hematology Association, held in Madrid, Spain.
Patients with R/R LBCL are often older, with many aged over 75, yet patients in those age groups are frequently underrepresented in clinical trials of CD19-directed CAR T-cell therapy, which has significantly improved outcomes for patients with R/R LBCL.
To further investigate differences in outcomes between older and younger patients with R/R LBCL treated with CAR-T cell therapy, Dr. Bories and colleagues conducted a retrospective analysis of 1,524 patients in the French DESCAR-T registry who were treated at treated at 31 centers in France and had at least two previous infusions of CAR-T cell therapy between April 2018 and September 2023.
Of the patients, 69.8% (n = 1065) were treated with axicabtagene ciloleucel (axi-cel), while 30.1% (n = 459) were treated with tisagenlecleucel (tisa-cel).
Among those patients, 125 were 75 years old or older, with a median age of 76, and the remaining 1399 were under the age of 75, with a median age of 62.
The two age groups had significant differences in terms of characteristics including gender, LBCL subset, number of prior lines of therapy, performance status, age-adjusted International Prognostic Index (IPI), rate of patients receiving a bridging therapy, response to the bridging therapy, and LDH at time of infusion.
Compared with patients aged 75 or younger, those who were 75 years or older had a higher hematopoietic cell transplantation–specific comorbidity index (HCT-CI) score, (31.2% high HCT-CI versus 16.8%, respectively; P < .001).
Patients over 75 also had fewer prior transplants than those under 75 (4.8% versus 21.8%, respectively; P < .001), and they more commonly received tisa-cel CAR-T cell therapy (43.2% versus 28.9%, respectively; P < .001).
Among 1457 patients with response data available, with a median follow-up of 12.7 months, there were no significant differences in terms of the best overall response rate (ORR) and complete response rates (CRR) between the two age groups, with rates of 74.8% for ORR and 62.6% for CRR among those 75 or older, compared with 78.0% and 60.8%, respectively, in the under 75 group (P = .425 and P = .699, respectively).
Likewise, the estimated median overall survival (OS) was 18.3 months in the 75 and older group and 24.0 months in the under 75 group (P = .12).
There were also no significant difference in terms of the estimated median progression-free survival, of 8.2 months in the 75 and older group versus 6.1 months in the under 75 group (P = .73).
In terms of safety, there were no significant differences in terms of grade 3 or higher cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) among patients 75 and older versus under 75, with 7.3% versus 7.4% developing CRS, respectively (P = .97), and 9.8% versus 12.4% developing ICANS (P = .39).
There were no significant differences between the age groups regarding ICU admissions, which occurred in about 24% of the cohorts, or the need for mechanical ventilation, which was necessary in about 3% of the entire cohort.
Of note, the overall rates of non-relapse mortality were more common in the 75 years and older group, among whom 19.5% of deaths were not related to lymphoma progression or relapse, compared with 8.1% in the under 75 group (P < .0001).
Early mortalities not related to relapse, defined as occurring before day 28 post-infusion, occurred among 3 patients aged 75 and older (2.4% of all patients 75 and older, representing 12.0% of all non-relapse mortality cases) compared with 16 patients under 75 (1.2% of those patients and 13.1% of all non-relapse mortality).
Infection was the main cause of non-relapse mortality in both groups, representing the cause in 57.7% of those under 75 and 54.2% of those aged 75 and older.
Patients 75 and older had a significantly higher risk of non-relapse mortality from infection (P = .0003), CRS (P = .022) or other causes, compared with those under 75 (P = .0004), but not from ICANS (P = .524).
“Our findings show a higher non-relapse mortality in this older population, which mainly relied on late infectious events, occurring after 28 days,” Dr. Bories said.
“There was also a higher rate of non-relapse mortality from infections, CRS or other causes in those 75 or older, but that did not translate to a lower overall survival in our patient sample,” he said.
Asked at the session about the implications of the higher infection risk in elderly patients, Dr. Bories said, “I think this deserves special attention and we have to be more careful with frail patients.
“This should obviously encourage the use of prophylaxis for a longer period of time.”
Dr. Bories noted that he and his team are currently conducting a more detailed propensity-matched comparison between axi-cel and tisa-cel in an older population.
The findings are consistent with those of other studies, among the latest including a 2024 real-world multicenter study of 172 diffuse LBCL (DLBCL) patients treated with CAR-T cell therapy (mostly axi-cel).
That study showed comparable median progression-free and OS rates between those over and under the age of 70, however, in contrast to the current study, that study showed no significant differences in non-relapse mortality.
The ORR in that study also did not differ between age groups, exceeding 75%.
Of note, in that study, tisa‐cel treatment was associated with an approximately 60% higher risk of relapse and/or death compared with axi‐cel treatment, which the authors report was driven primarily by less favorable survival outcomes among tisa‐cel patients younger than age 70 years.
“In this context, some reports showed that axi‐cel may offer enhanced effectiveness compared to tisa‐cel in patients aged 65 and older, despite higher rates of neurotoxicity,” they wrote.
Nevertheless, the study’s overall findings indicate that “CAR T-cell therapy should be not withheld for elderly patients with r/r DLBCL,” the authors concluded.
Low CAR T Utilization in Elderly Patients
Overall, utilization of CAR-T cell therapy among older patients reportedly remains low, as demonstrated in one recent real-world study on the issue, involving 551 older patients with DLBCL.
The study showed that 19% of patients aged 65-69 and 22% of those aged 70-74 years received CAR-T cell therapy, compared with only 13% of those aged 75 and older.
“While CAR T-cell therapy in older patients is associated with favorable event-free survival comparable to outcomes in younger patients, CAR T-cell usage is low in older patients with DLBCL, which suggests an unmet need for more accessible, effective, and tolerable therapy,” reported first author Dia Chihara, MD, PhD, of the Department of Lymphoma and Myeloma, The University of Texas MD Anderson Cancer Center, in Houston, Texas, and colleagues.
Noting that “the use of current CAR-T cell therapy products seemed to be limited to selected patients,” the authors added that “this may change in the future with next-generation CAR T-cell therapy products.”
Dr. Bories disclosed relationships with Kite Gilead, Novartis, BMD-Celgene, Abbvie, Servier, Janssen and the BMS foundation.
“This real-world study demonstrates that CD19 CAR-T cell therapy is feasible in a population of patients aged 75 years and older,” said senior author Pierre Bories, MD, PhD, of the Institute for Cancer Strasbourg-Europe, in Alsace, France. He presented the findings at the annual meeting of the European Hematology Association, held in Madrid, Spain.
Patients with R/R LBCL are often older, with many aged over 75, yet patients in those age groups are frequently underrepresented in clinical trials of CD19-directed CAR T-cell therapy, which has significantly improved outcomes for patients with R/R LBCL.
To further investigate differences in outcomes between older and younger patients with R/R LBCL treated with CAR-T cell therapy, Dr. Bories and colleagues conducted a retrospective analysis of 1,524 patients in the French DESCAR-T registry who were treated at treated at 31 centers in France and had at least two previous infusions of CAR-T cell therapy between April 2018 and September 2023.
Of the patients, 69.8% (n = 1065) were treated with axicabtagene ciloleucel (axi-cel), while 30.1% (n = 459) were treated with tisagenlecleucel (tisa-cel).
Among those patients, 125 were 75 years old or older, with a median age of 76, and the remaining 1399 were under the age of 75, with a median age of 62.
The two age groups had significant differences in terms of characteristics including gender, LBCL subset, number of prior lines of therapy, performance status, age-adjusted International Prognostic Index (IPI), rate of patients receiving a bridging therapy, response to the bridging therapy, and LDH at time of infusion.
Compared with patients aged 75 or younger, those who were 75 years or older had a higher hematopoietic cell transplantation–specific comorbidity index (HCT-CI) score, (31.2% high HCT-CI versus 16.8%, respectively; P < .001).
Patients over 75 also had fewer prior transplants than those under 75 (4.8% versus 21.8%, respectively; P < .001), and they more commonly received tisa-cel CAR-T cell therapy (43.2% versus 28.9%, respectively; P < .001).
Among 1457 patients with response data available, with a median follow-up of 12.7 months, there were no significant differences in terms of the best overall response rate (ORR) and complete response rates (CRR) between the two age groups, with rates of 74.8% for ORR and 62.6% for CRR among those 75 or older, compared with 78.0% and 60.8%, respectively, in the under 75 group (P = .425 and P = .699, respectively).
Likewise, the estimated median overall survival (OS) was 18.3 months in the 75 and older group and 24.0 months in the under 75 group (P = .12).
There were also no significant difference in terms of the estimated median progression-free survival, of 8.2 months in the 75 and older group versus 6.1 months in the under 75 group (P = .73).
In terms of safety, there were no significant differences in terms of grade 3 or higher cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) among patients 75 and older versus under 75, with 7.3% versus 7.4% developing CRS, respectively (P = .97), and 9.8% versus 12.4% developing ICANS (P = .39).
There were no significant differences between the age groups regarding ICU admissions, which occurred in about 24% of the cohorts, or the need for mechanical ventilation, which was necessary in about 3% of the entire cohort.
Of note, the overall rates of non-relapse mortality were more common in the 75 years and older group, among whom 19.5% of deaths were not related to lymphoma progression or relapse, compared with 8.1% in the under 75 group (P < .0001).
Early mortalities not related to relapse, defined as occurring before day 28 post-infusion, occurred among 3 patients aged 75 and older (2.4% of all patients 75 and older, representing 12.0% of all non-relapse mortality cases) compared with 16 patients under 75 (1.2% of those patients and 13.1% of all non-relapse mortality).
Infection was the main cause of non-relapse mortality in both groups, representing the cause in 57.7% of those under 75 and 54.2% of those aged 75 and older.
Patients 75 and older had a significantly higher risk of non-relapse mortality from infection (P = .0003), CRS (P = .022) or other causes, compared with those under 75 (P = .0004), but not from ICANS (P = .524).
“Our findings show a higher non-relapse mortality in this older population, which mainly relied on late infectious events, occurring after 28 days,” Dr. Bories said.
“There was also a higher rate of non-relapse mortality from infections, CRS or other causes in those 75 or older, but that did not translate to a lower overall survival in our patient sample,” he said.
Asked at the session about the implications of the higher infection risk in elderly patients, Dr. Bories said, “I think this deserves special attention and we have to be more careful with frail patients.
“This should obviously encourage the use of prophylaxis for a longer period of time.”
Dr. Bories noted that he and his team are currently conducting a more detailed propensity-matched comparison between axi-cel and tisa-cel in an older population.
The findings are consistent with those of other studies, among the latest including a 2024 real-world multicenter study of 172 diffuse LBCL (DLBCL) patients treated with CAR-T cell therapy (mostly axi-cel).
That study showed comparable median progression-free and OS rates between those over and under the age of 70, however, in contrast to the current study, that study showed no significant differences in non-relapse mortality.
The ORR in that study also did not differ between age groups, exceeding 75%.
Of note, in that study, tisa‐cel treatment was associated with an approximately 60% higher risk of relapse and/or death compared with axi‐cel treatment, which the authors report was driven primarily by less favorable survival outcomes among tisa‐cel patients younger than age 70 years.
“In this context, some reports showed that axi‐cel may offer enhanced effectiveness compared to tisa‐cel in patients aged 65 and older, despite higher rates of neurotoxicity,” they wrote.
Nevertheless, the study’s overall findings indicate that “CAR T-cell therapy should be not withheld for elderly patients with r/r DLBCL,” the authors concluded.
Low CAR T Utilization in Elderly Patients
Overall, utilization of CAR-T cell therapy among older patients reportedly remains low, as demonstrated in one recent real-world study on the issue, involving 551 older patients with DLBCL.
The study showed that 19% of patients aged 65-69 and 22% of those aged 70-74 years received CAR-T cell therapy, compared with only 13% of those aged 75 and older.
“While CAR T-cell therapy in older patients is associated with favorable event-free survival comparable to outcomes in younger patients, CAR T-cell usage is low in older patients with DLBCL, which suggests an unmet need for more accessible, effective, and tolerable therapy,” reported first author Dia Chihara, MD, PhD, of the Department of Lymphoma and Myeloma, The University of Texas MD Anderson Cancer Center, in Houston, Texas, and colleagues.
Noting that “the use of current CAR-T cell therapy products seemed to be limited to selected patients,” the authors added that “this may change in the future with next-generation CAR T-cell therapy products.”
Dr. Bories disclosed relationships with Kite Gilead, Novartis, BMD-Celgene, Abbvie, Servier, Janssen and the BMS foundation.
“This real-world study demonstrates that CD19 CAR-T cell therapy is feasible in a population of patients aged 75 years and older,” said senior author Pierre Bories, MD, PhD, of the Institute for Cancer Strasbourg-Europe, in Alsace, France. He presented the findings at the annual meeting of the European Hematology Association, held in Madrid, Spain.
Patients with R/R LBCL are often older, with many aged over 75, yet patients in those age groups are frequently underrepresented in clinical trials of CD19-directed CAR T-cell therapy, which has significantly improved outcomes for patients with R/R LBCL.
To further investigate differences in outcomes between older and younger patients with R/R LBCL treated with CAR-T cell therapy, Dr. Bories and colleagues conducted a retrospective analysis of 1,524 patients in the French DESCAR-T registry who were treated at treated at 31 centers in France and had at least two previous infusions of CAR-T cell therapy between April 2018 and September 2023.
Of the patients, 69.8% (n = 1065) were treated with axicabtagene ciloleucel (axi-cel), while 30.1% (n = 459) were treated with tisagenlecleucel (tisa-cel).
Among those patients, 125 were 75 years old or older, with a median age of 76, and the remaining 1399 were under the age of 75, with a median age of 62.
The two age groups had significant differences in terms of characteristics including gender, LBCL subset, number of prior lines of therapy, performance status, age-adjusted International Prognostic Index (IPI), rate of patients receiving a bridging therapy, response to the bridging therapy, and LDH at time of infusion.
Compared with patients aged 75 or younger, those who were 75 years or older had a higher hematopoietic cell transplantation–specific comorbidity index (HCT-CI) score, (31.2% high HCT-CI versus 16.8%, respectively; P < .001).
Patients over 75 also had fewer prior transplants than those under 75 (4.8% versus 21.8%, respectively; P < .001), and they more commonly received tisa-cel CAR-T cell therapy (43.2% versus 28.9%, respectively; P < .001).
Among 1457 patients with response data available, with a median follow-up of 12.7 months, there were no significant differences in terms of the best overall response rate (ORR) and complete response rates (CRR) between the two age groups, with rates of 74.8% for ORR and 62.6% for CRR among those 75 or older, compared with 78.0% and 60.8%, respectively, in the under 75 group (P = .425 and P = .699, respectively).
Likewise, the estimated median overall survival (OS) was 18.3 months in the 75 and older group and 24.0 months in the under 75 group (P = .12).
There were also no significant difference in terms of the estimated median progression-free survival, of 8.2 months in the 75 and older group versus 6.1 months in the under 75 group (P = .73).
In terms of safety, there were no significant differences in terms of grade 3 or higher cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) among patients 75 and older versus under 75, with 7.3% versus 7.4% developing CRS, respectively (P = .97), and 9.8% versus 12.4% developing ICANS (P = .39).
There were no significant differences between the age groups regarding ICU admissions, which occurred in about 24% of the cohorts, or the need for mechanical ventilation, which was necessary in about 3% of the entire cohort.
Of note, the overall rates of non-relapse mortality were more common in the 75 years and older group, among whom 19.5% of deaths were not related to lymphoma progression or relapse, compared with 8.1% in the under 75 group (P < .0001).
Early mortalities not related to relapse, defined as occurring before day 28 post-infusion, occurred among 3 patients aged 75 and older (2.4% of all patients 75 and older, representing 12.0% of all non-relapse mortality cases) compared with 16 patients under 75 (1.2% of those patients and 13.1% of all non-relapse mortality).
Infection was the main cause of non-relapse mortality in both groups, representing the cause in 57.7% of those under 75 and 54.2% of those aged 75 and older.
Patients 75 and older had a significantly higher risk of non-relapse mortality from infection (P = .0003), CRS (P = .022) or other causes, compared with those under 75 (P = .0004), but not from ICANS (P = .524).
“Our findings show a higher non-relapse mortality in this older population, which mainly relied on late infectious events, occurring after 28 days,” Dr. Bories said.
“There was also a higher rate of non-relapse mortality from infections, CRS or other causes in those 75 or older, but that did not translate to a lower overall survival in our patient sample,” he said.
Asked at the session about the implications of the higher infection risk in elderly patients, Dr. Bories said, “I think this deserves special attention and we have to be more careful with frail patients.
“This should obviously encourage the use of prophylaxis for a longer period of time.”
Dr. Bories noted that he and his team are currently conducting a more detailed propensity-matched comparison between axi-cel and tisa-cel in an older population.
The findings are consistent with those of other studies, among the latest including a 2024 real-world multicenter study of 172 diffuse LBCL (DLBCL) patients treated with CAR-T cell therapy (mostly axi-cel).
That study showed comparable median progression-free and OS rates between those over and under the age of 70, however, in contrast to the current study, that study showed no significant differences in non-relapse mortality.
The ORR in that study also did not differ between age groups, exceeding 75%.
Of note, in that study, tisa‐cel treatment was associated with an approximately 60% higher risk of relapse and/or death compared with axi‐cel treatment, which the authors report was driven primarily by less favorable survival outcomes among tisa‐cel patients younger than age 70 years.
“In this context, some reports showed that axi‐cel may offer enhanced effectiveness compared to tisa‐cel in patients aged 65 and older, despite higher rates of neurotoxicity,” they wrote.
Nevertheless, the study’s overall findings indicate that “CAR T-cell therapy should be not withheld for elderly patients with r/r DLBCL,” the authors concluded.
Low CAR T Utilization in Elderly Patients
Overall, utilization of CAR-T cell therapy among older patients reportedly remains low, as demonstrated in one recent real-world study on the issue, involving 551 older patients with DLBCL.
The study showed that 19% of patients aged 65-69 and 22% of those aged 70-74 years received CAR-T cell therapy, compared with only 13% of those aged 75 and older.
“While CAR T-cell therapy in older patients is associated with favorable event-free survival comparable to outcomes in younger patients, CAR T-cell usage is low in older patients with DLBCL, which suggests an unmet need for more accessible, effective, and tolerable therapy,” reported first author Dia Chihara, MD, PhD, of the Department of Lymphoma and Myeloma, The University of Texas MD Anderson Cancer Center, in Houston, Texas, and colleagues.
Noting that “the use of current CAR-T cell therapy products seemed to be limited to selected patients,” the authors added that “this may change in the future with next-generation CAR T-cell therapy products.”
Dr. Bories disclosed relationships with Kite Gilead, Novartis, BMD-Celgene, Abbvie, Servier, Janssen and the BMS foundation.
FROM EHA 2024
Hemophilia: Marstacimab Sustains Long-Term Bleeding Reduction
“In the long-term extension study treatment with marstacimab demonstrates sustained or improved efficacy for treated and total annualized bleeding rates (ABR) in adults and adolescents with hemophilia A or hemophilia B in this data set of patients without inhibitors,” first author Shamsah Kazani, MD, of Pfizer, Cambridge, Massachusetts, said in presenting the findings at the 2024 annual meeting of the European Hematology Association (EHA) in Madrid.
“The majority of the patients from the pivotal study chose to transition into the long-term extension, and we are finding that these patients are highly compliant with their weekly marstacimab dose, with more than 98% compliance,” Dr. Kazani said.
Marstacimab targets the tissue factor pathway inhibitor, a natural anticoagulation protein that prevents the formation of blood clots, and is administered as a once-weekly subcutaneous injection.
The therapy has been granted fast-track and orphan drug status in the United States, in addition to orphan drug status in the European Union for the prevention of hemophilia bleeding episodes.
If approved, the therapy would become the first once-weekly subcutaneous therapy for either hemophilia A or B. Emicizumab, which also is administered subcutaneously, is only approved to prevent or reduce bleeding in hemophilia A.
The latest findings are from an interim analysis of a long-term extension study involving 107 of 116 patients who were in the non-inhibitor cohort in the pivotal BASIS trial. Data from that trial, involving patients aged 12-75 previously showed favorable outcomes in the non-inhibitor cohort receiving marstacimab, and a cohort of patients with inhibitors is ongoing.
Participants entering the extension study were continuing on 150-mg subcutaneous doses of marstacimab, which had been administered in the BASIS study for 12 months after a loading dose of 300 mg.
Of the patients, 89 (83%) were adult and 18 (17%) were adolescents. Overall, they had a mean age of 29 years; 83 (76%) patients had hemophilia A, while 24 (22.4%) had hemophilia B.
Prior to switching to marstacimab treatment, 32 patients had been treated with factor replacement therapy on demand, while 75 received the therapy as routine prophylaxis.
With a mean additional duration of follow-up of 12.5 months in the extension study (range, 1-23.1 months), the overall rate of compliance was very high, at 98.9%.
In the pivotal and extension studies combined, 21% of patients had their marstacimab dose increased from 150 mg to 300 mg weekly, which was an option if patients had 2 or more spontaneous bleeds in a major joint while on the 150-mg dose.
In the hemophilia A and B groups combined, those previously treated with on-demand factor replacement therapy (n = 33) had substantial reductions in estimated ABR for treated bleeds from the baseline of 38.0 prior to initiating marstacimab, to 3.2 after 12 months of the treatment in the trial (P < .001).That reduction was sustained at an ABR of 3.7 after the mean additional 12.5 months in the extension study.
The corresponding estimated ABR rates in the routine prophylaxis group (n = 83) were 7.9 at baseline, 5.1 at the end of the trial, and 2.8 in the extension study analysis interim cutoff.
The authors then further stratified the results based on hemophilia A or B groups: Among patients with hemophilia A (n = 26), the on-demand subgroup had a baseline ABR of 40.6, which dropped substantially to just 3.6 after 12 months on marstacimab in the pivotal trial and was sustained at 5.3 in the extension study.
Similar trends were observed in the hemophilia A group who received routine prophylaxis (n = 65), with an ABR of 9.2 at baseline; 5.3 after the trial, and 3.1 at the extension study interim.
The trends were similar among those with hemophilia B, albeit with lower numbers of patients, consistent with hemophilia B being more rare.
The mean ABR at baseline in the on-demand group of those patients (n = 7) was 28.7, which was reduced to just 1.7 after the 12-months of active marstacimab treatment and sustained at 1.8 by the interim analysis of the extension study.
Of hemophilia B patients previously on routine prophylaxis (n = 18), the mean ABR at baseline was 3.3 and was at 4.7 at the end of the trial. The rate declined to 2.3 in the extension phase.
“We see that these trends of improvement with marstacimab are sustained into the long-term extension study, both in the on-demand group and in the routine prophylaxis groups,” Dr. Kazani said.
Importantly, she noted that marstacimab continued to be well tolerated and safe in the long-term extension study, with no reports of thromboembolic events, which had been a concern with the drug.
Commenting on the study, Margaret Ragni, MD, MPH, a professor of medicine and clinical and translational research in the Division of Hematology/Oncology at the University of Pittsburgh, Pittsburgh, Pennsylvania, noted that marstacimab could represent an important addition in the prevention of bleeds in hemophilia. “[If marstacimab is approved], hemophilia B patients [will] have a drug that can be given subcutaneously weekly to rebalance hemostasis, reducing bleeds, just as hemophilia A patients have with emicizumab.”
Dr. Ragni underscored, however, that caveats include the important point that “neither [marstacimab nor emicizumab] treats bleeds. For that, standard factor replacement therapy or bypass for inhibitors, would be required.”
Also, “a limitation with marstacimab is the lack of weight-dependent dosing. All use one dose [however, in the studies they did use 150 mg or 300 mg]. ... Furthermore, emicizumab can be given weekly, biweekly, or monthly, while that [variation in dosing] is not yet studied with marstacimab.”
And while no thromboembolic events occurred during the trial, Dr. Ragni underscored that “longer-term follow-up is needed.”
The marstacimab long-term extension study is designed to extend to 7 years of follow-up.
The study was sponsored by Pfizer, and Dr. Kazani is an employee of Pfizer. Dr. Ragni reported no disclosures.
“In the long-term extension study treatment with marstacimab demonstrates sustained or improved efficacy for treated and total annualized bleeding rates (ABR) in adults and adolescents with hemophilia A or hemophilia B in this data set of patients without inhibitors,” first author Shamsah Kazani, MD, of Pfizer, Cambridge, Massachusetts, said in presenting the findings at the 2024 annual meeting of the European Hematology Association (EHA) in Madrid.
“The majority of the patients from the pivotal study chose to transition into the long-term extension, and we are finding that these patients are highly compliant with their weekly marstacimab dose, with more than 98% compliance,” Dr. Kazani said.
Marstacimab targets the tissue factor pathway inhibitor, a natural anticoagulation protein that prevents the formation of blood clots, and is administered as a once-weekly subcutaneous injection.
The therapy has been granted fast-track and orphan drug status in the United States, in addition to orphan drug status in the European Union for the prevention of hemophilia bleeding episodes.
If approved, the therapy would become the first once-weekly subcutaneous therapy for either hemophilia A or B. Emicizumab, which also is administered subcutaneously, is only approved to prevent or reduce bleeding in hemophilia A.
The latest findings are from an interim analysis of a long-term extension study involving 107 of 116 patients who were in the non-inhibitor cohort in the pivotal BASIS trial. Data from that trial, involving patients aged 12-75 previously showed favorable outcomes in the non-inhibitor cohort receiving marstacimab, and a cohort of patients with inhibitors is ongoing.
Participants entering the extension study were continuing on 150-mg subcutaneous doses of marstacimab, which had been administered in the BASIS study for 12 months after a loading dose of 300 mg.
Of the patients, 89 (83%) were adult and 18 (17%) were adolescents. Overall, they had a mean age of 29 years; 83 (76%) patients had hemophilia A, while 24 (22.4%) had hemophilia B.
Prior to switching to marstacimab treatment, 32 patients had been treated with factor replacement therapy on demand, while 75 received the therapy as routine prophylaxis.
With a mean additional duration of follow-up of 12.5 months in the extension study (range, 1-23.1 months), the overall rate of compliance was very high, at 98.9%.
In the pivotal and extension studies combined, 21% of patients had their marstacimab dose increased from 150 mg to 300 mg weekly, which was an option if patients had 2 or more spontaneous bleeds in a major joint while on the 150-mg dose.
In the hemophilia A and B groups combined, those previously treated with on-demand factor replacement therapy (n = 33) had substantial reductions in estimated ABR for treated bleeds from the baseline of 38.0 prior to initiating marstacimab, to 3.2 after 12 months of the treatment in the trial (P < .001).That reduction was sustained at an ABR of 3.7 after the mean additional 12.5 months in the extension study.
The corresponding estimated ABR rates in the routine prophylaxis group (n = 83) were 7.9 at baseline, 5.1 at the end of the trial, and 2.8 in the extension study analysis interim cutoff.
The authors then further stratified the results based on hemophilia A or B groups: Among patients with hemophilia A (n = 26), the on-demand subgroup had a baseline ABR of 40.6, which dropped substantially to just 3.6 after 12 months on marstacimab in the pivotal trial and was sustained at 5.3 in the extension study.
Similar trends were observed in the hemophilia A group who received routine prophylaxis (n = 65), with an ABR of 9.2 at baseline; 5.3 after the trial, and 3.1 at the extension study interim.
The trends were similar among those with hemophilia B, albeit with lower numbers of patients, consistent with hemophilia B being more rare.
The mean ABR at baseline in the on-demand group of those patients (n = 7) was 28.7, which was reduced to just 1.7 after the 12-months of active marstacimab treatment and sustained at 1.8 by the interim analysis of the extension study.
Of hemophilia B patients previously on routine prophylaxis (n = 18), the mean ABR at baseline was 3.3 and was at 4.7 at the end of the trial. The rate declined to 2.3 in the extension phase.
“We see that these trends of improvement with marstacimab are sustained into the long-term extension study, both in the on-demand group and in the routine prophylaxis groups,” Dr. Kazani said.
Importantly, she noted that marstacimab continued to be well tolerated and safe in the long-term extension study, with no reports of thromboembolic events, which had been a concern with the drug.
Commenting on the study, Margaret Ragni, MD, MPH, a professor of medicine and clinical and translational research in the Division of Hematology/Oncology at the University of Pittsburgh, Pittsburgh, Pennsylvania, noted that marstacimab could represent an important addition in the prevention of bleeds in hemophilia. “[If marstacimab is approved], hemophilia B patients [will] have a drug that can be given subcutaneously weekly to rebalance hemostasis, reducing bleeds, just as hemophilia A patients have with emicizumab.”
Dr. Ragni underscored, however, that caveats include the important point that “neither [marstacimab nor emicizumab] treats bleeds. For that, standard factor replacement therapy or bypass for inhibitors, would be required.”
Also, “a limitation with marstacimab is the lack of weight-dependent dosing. All use one dose [however, in the studies they did use 150 mg or 300 mg]. ... Furthermore, emicizumab can be given weekly, biweekly, or monthly, while that [variation in dosing] is not yet studied with marstacimab.”
And while no thromboembolic events occurred during the trial, Dr. Ragni underscored that “longer-term follow-up is needed.”
The marstacimab long-term extension study is designed to extend to 7 years of follow-up.
The study was sponsored by Pfizer, and Dr. Kazani is an employee of Pfizer. Dr. Ragni reported no disclosures.
“In the long-term extension study treatment with marstacimab demonstrates sustained or improved efficacy for treated and total annualized bleeding rates (ABR) in adults and adolescents with hemophilia A or hemophilia B in this data set of patients without inhibitors,” first author Shamsah Kazani, MD, of Pfizer, Cambridge, Massachusetts, said in presenting the findings at the 2024 annual meeting of the European Hematology Association (EHA) in Madrid.
“The majority of the patients from the pivotal study chose to transition into the long-term extension, and we are finding that these patients are highly compliant with their weekly marstacimab dose, with more than 98% compliance,” Dr. Kazani said.
Marstacimab targets the tissue factor pathway inhibitor, a natural anticoagulation protein that prevents the formation of blood clots, and is administered as a once-weekly subcutaneous injection.
The therapy has been granted fast-track and orphan drug status in the United States, in addition to orphan drug status in the European Union for the prevention of hemophilia bleeding episodes.
If approved, the therapy would become the first once-weekly subcutaneous therapy for either hemophilia A or B. Emicizumab, which also is administered subcutaneously, is only approved to prevent or reduce bleeding in hemophilia A.
The latest findings are from an interim analysis of a long-term extension study involving 107 of 116 patients who were in the non-inhibitor cohort in the pivotal BASIS trial. Data from that trial, involving patients aged 12-75 previously showed favorable outcomes in the non-inhibitor cohort receiving marstacimab, and a cohort of patients with inhibitors is ongoing.
Participants entering the extension study were continuing on 150-mg subcutaneous doses of marstacimab, which had been administered in the BASIS study for 12 months after a loading dose of 300 mg.
Of the patients, 89 (83%) were adult and 18 (17%) were adolescents. Overall, they had a mean age of 29 years; 83 (76%) patients had hemophilia A, while 24 (22.4%) had hemophilia B.
Prior to switching to marstacimab treatment, 32 patients had been treated with factor replacement therapy on demand, while 75 received the therapy as routine prophylaxis.
With a mean additional duration of follow-up of 12.5 months in the extension study (range, 1-23.1 months), the overall rate of compliance was very high, at 98.9%.
In the pivotal and extension studies combined, 21% of patients had their marstacimab dose increased from 150 mg to 300 mg weekly, which was an option if patients had 2 or more spontaneous bleeds in a major joint while on the 150-mg dose.
In the hemophilia A and B groups combined, those previously treated with on-demand factor replacement therapy (n = 33) had substantial reductions in estimated ABR for treated bleeds from the baseline of 38.0 prior to initiating marstacimab, to 3.2 after 12 months of the treatment in the trial (P < .001).That reduction was sustained at an ABR of 3.7 after the mean additional 12.5 months in the extension study.
The corresponding estimated ABR rates in the routine prophylaxis group (n = 83) were 7.9 at baseline, 5.1 at the end of the trial, and 2.8 in the extension study analysis interim cutoff.
The authors then further stratified the results based on hemophilia A or B groups: Among patients with hemophilia A (n = 26), the on-demand subgroup had a baseline ABR of 40.6, which dropped substantially to just 3.6 after 12 months on marstacimab in the pivotal trial and was sustained at 5.3 in the extension study.
Similar trends were observed in the hemophilia A group who received routine prophylaxis (n = 65), with an ABR of 9.2 at baseline; 5.3 after the trial, and 3.1 at the extension study interim.
The trends were similar among those with hemophilia B, albeit with lower numbers of patients, consistent with hemophilia B being more rare.
The mean ABR at baseline in the on-demand group of those patients (n = 7) was 28.7, which was reduced to just 1.7 after the 12-months of active marstacimab treatment and sustained at 1.8 by the interim analysis of the extension study.
Of hemophilia B patients previously on routine prophylaxis (n = 18), the mean ABR at baseline was 3.3 and was at 4.7 at the end of the trial. The rate declined to 2.3 in the extension phase.
“We see that these trends of improvement with marstacimab are sustained into the long-term extension study, both in the on-demand group and in the routine prophylaxis groups,” Dr. Kazani said.
Importantly, she noted that marstacimab continued to be well tolerated and safe in the long-term extension study, with no reports of thromboembolic events, which had been a concern with the drug.
Commenting on the study, Margaret Ragni, MD, MPH, a professor of medicine and clinical and translational research in the Division of Hematology/Oncology at the University of Pittsburgh, Pittsburgh, Pennsylvania, noted that marstacimab could represent an important addition in the prevention of bleeds in hemophilia. “[If marstacimab is approved], hemophilia B patients [will] have a drug that can be given subcutaneously weekly to rebalance hemostasis, reducing bleeds, just as hemophilia A patients have with emicizumab.”
Dr. Ragni underscored, however, that caveats include the important point that “neither [marstacimab nor emicizumab] treats bleeds. For that, standard factor replacement therapy or bypass for inhibitors, would be required.”
Also, “a limitation with marstacimab is the lack of weight-dependent dosing. All use one dose [however, in the studies they did use 150 mg or 300 mg]. ... Furthermore, emicizumab can be given weekly, biweekly, or monthly, while that [variation in dosing] is not yet studied with marstacimab.”
And while no thromboembolic events occurred during the trial, Dr. Ragni underscored that “longer-term follow-up is needed.”
The marstacimab long-term extension study is designed to extend to 7 years of follow-up.
The study was sponsored by Pfizer, and Dr. Kazani is an employee of Pfizer. Dr. Ragni reported no disclosures.
FROM EHA 2024
DLBCL: Glofitamab Plus Chemo Boosts Survival
“Glofitamab is the first CD20xCD3 bispecific antibody to demonstrate an overall survival benefit in DLBCL in a randomized phase 3 trial,” said first author Jeremy Abramson, MD, of the Massachusetts General Hospital Cancer Center, Boston, Massachusetts, in a press briefing at the annual meeting of the European Hematology Association (EHA) in Madrid.
“These results support the use of glofitamab GemOx as new, off-the-shelf treatment for relapsed/refractory DLBCL in patients who are transplant ineligible in the second-line or later setting,” he said.
The findings are from the phase 3 STARGLO study involving 274 patients with R/R DLBCL who had previously been treated either with at least two prior lines of therapy, or—if only one prior line of therapy—were determined to be ineligible for autologous stem cell transplant (ASCT).
At a median follow-up of 21 months, those treated with glofitamab combined with GemOx had a significantly higher median overall survival of 25.5 months, compared with those treated with the standard of care of rituximab and GemOx (12.9 months; hazard ratio [HR], 0.62; P = .006).
“The results show a 38% lower risk of death with the glofitamab plus GemOx, compared with [the rituximab regimen],” Dr. Abramson said.
Secondary endpoints showed consistent benefits with the glofitamab regimen, with significant improvements in progression-free survival and complete remission.
Unmet Need for Accessible Therapies
Relapsed/refractory DLBCL, the most common form of non-Hodgkin lymphoma (NHL) in the United States, is an aggressive blood cancer. The standard second-line therapy is high-dose chemotherapy followed by ASCT. However, factors including older age or coexisting medical conditions can compromise response, and those who relapse or are refractory to subsequent therapies have poor outcomes.
“Relapsed DLBCL in the second-line setting or later continues to represent an area of medical need,” Dr. Abramson said.
While several CD20xCD3 bispecific antibody drugs are under development to address the need, glofitamab was the first off-the-shelf, fixed-duration bispecific antibody to receive accelerated approval from the US Food and Drug Administration (FDA) for the treatment of R/R DLBCL, specifically as monotherapy after two or more lines of systemic therapy.
That approval was based on results from a pivotal phase 1/2 study, which showed high rates of deep and durable complete remission with the monotherapy.
To further evaluate glofitamab in combination with GemOx, the authors conducted the multicenter, open-label STARGLO trial, which extended enrollment to patients with just one prior therapy if they were determined to be stem cell transplant ineligible. Patients were also required to have an Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2.
Patients were randomized 2:1 either to treatment with glofitamab combined with GemOx, involving 8 cycles, in addition to 4 cycles of glofitamab monotherapy (n = 183), or to the rituximab plus GemOx regimen in 8 cycles (n = 91).
Overall, 153 (55.8%) of patients had primary refractory disease and 166 (60.6%) were refractory to their last therapy. The median age was 68, and 37% had two or more lines of therapy, including some who had received chimeric antigen receptor T-cell (CAR T) therapy (8.8% in the glofitamab group and 7.1% in the rituximab group).
In addition to the significant overall survival benefit, the glofitamab regimen also showed significantly improved progression-free survival at a median follow-up of 16.1 months, as observed by IRC-assessed PFS, with a median progression-free survival rate of 13.8 months vs 3.6 months (HR, 0.40; P < .0001).
The complete remission rate was doubled with glofitamab-GemOx, with a rate of 58.5% vs 25.3%, respectively; P < .0001.
Similar results were observed in subgroups, including relapsed vs refractory patients and those treated as a second or third line of care.
The median number of cycles received was higher among those receiving glofitamab (11 vs four cycles).
Adverse event (AE) rates were higher with glofitamab vs rituximab, including grade 3-4 AEs (69.4 vs 36.4%), grade 5 AEs (8.3 vs 4.5%; primarily driven by an imbalance of COVID-19 AEs), and serious AEs (54.4 vs 17.0%; primarily cytokine release syndrome [CRS]).
CRS was the most frequently reported AE in the glofitamab group (grade 1: 31.4%; grade 2: 10.5%; and grade 3: 2.3%), and events consistent with immune effector cell–associated neurotoxicity syndrome were reported in four patients (2.3%), all of which were concurrent with CRS.
Other AEs were consistent with the known risks associated with the therapy regimens.
“We found that with glofitamab GemOx, the toxicities were manageable, and the most common toxicity of CRS was predominantly low-grade and occurred with step-up dosing in cycle one and was completely reversible,” Dr. Abramson said.
He noted that the higher rate of grade 5 AEs with glofitamab GemOx “was far outweighed by the survival benefit for disease control.”
Overall, “these findings represent the best outcomes observed in a phase 3 trial for relapsed/refractory diffuse large B-cell lymphoma patients who are considered transplant ineligible,” Dr. Abramson said in an interview.
Improved Accessibility Vs CAR-T Therapy
Among key developments in the treatment of R/R DLBCL has been the advent and approval of potentially highly effective CAR T-cell therapy, with the anti-CD19 CAR T cell isiocabtagene maraleucel also FDA approved in the non–transplant eligible DLBCL second-line setting.
Asked in the press briefing about the role of glofitamab GemOx in relation to CAR T cell’s significant benefits, Dr. Abramson underscored the important limitations in CAR T-cell accessibility.
“What I would say is a rising tide lifts all boats,” he responded. “It’s great to have multiple effective immunotherapy strategies.”
However, “CAR T cells of course are not available to most people in the US or worldwide,” he explained.
“They are more difficult to access, they require lymphodepleting chemotherapy, and so ultimately, the majority of patients who could potentially benefit from a CAR T cell probably don’t have access to them in the first place.”
He noted that “the appeal of a regimen like [glofitamab] is that it is an off-the-shelf, targeted immunotherapy combined with a well-tolerated chemotherapy backbone and should be more broadly accessible outside of just tertiary care centers in major cities.”
Long-Term Durability?
Looking ahead, Dr. Abramson noted that a key issue of focus is how long the encouraging results actually last.
“The major ongoing question with this trial is the long-term durability of remissions,” he said.
“Thus far, with a median of 21 months of follow-up for overall survival, the results are encouraging but longer follow-up is needed,” he added.
“Further trials are needed in a broader large B-cell lymphoma population as this trial was limited to DLBCL not otherwise specified, so did not include patients with transformed lymphoma, primary mediastinal B-cell lymphoma, high grade B-cell lymphoma, etc.”
Is Chemo Necessary?
Commenting on the findings, Jonathan W. Friedberg, MD, director of the Wilmot Cancer Institute, University of Rochester School of Medicine, in Rochester, New York, underscored that, “given the overall survival benefit, these findings are clearly clinically significant.”
Noting that “these results add to evidence of high activity of bispecific antibodies in this disease,” Dr. Friedberg speculated on the role of chemotherapy with the therapy.
“Indeed, an important question in this study is whether the addition of chemotherapy to glofitamab is necessary, as high response rates with durable responses in patients who achieve complete remission have been demonstrated with single agent bispecific antibody therapy,” he said.
With the durability of CAR T therapy shown in long-term follow-up of trials to exceed 5 years, Dr. Friedberg added that “it is not known how bispecific antibody therapy, with or without chemotherapy, compares to CAR T-cell therapy and how to sequence CAR T and bispecific antibody therapy.”
Dr. Friedberg agreed that longer-term results are needed get a clearer, fuller picture of the therapy’s effects.
“I have no doubt that the overall survival benefit will endure, but in DLBCL our goal should be cure, and whether glofitamab cures as many patients as CAR T-cell therapy is not currently known and will require further follow-up of this and other trials.”
The study was sponsored by F. Hoffman-La Roche Ltd. Dr. Abramson reported ties with AbbVie, ADC Therapeutics, AstraZeneca, BeiGene, BMS, Cellectar, Caribou Biosciences, Celgene, Genentech, Gilead, Incyte, Interius, Janssen, Lilly, Novartis, F. Hoffmann-La Roche Ltd, Seagen, and Takeda. Dr. Friedberg had no disclosures.
“Glofitamab is the first CD20xCD3 bispecific antibody to demonstrate an overall survival benefit in DLBCL in a randomized phase 3 trial,” said first author Jeremy Abramson, MD, of the Massachusetts General Hospital Cancer Center, Boston, Massachusetts, in a press briefing at the annual meeting of the European Hematology Association (EHA) in Madrid.
“These results support the use of glofitamab GemOx as new, off-the-shelf treatment for relapsed/refractory DLBCL in patients who are transplant ineligible in the second-line or later setting,” he said.
The findings are from the phase 3 STARGLO study involving 274 patients with R/R DLBCL who had previously been treated either with at least two prior lines of therapy, or—if only one prior line of therapy—were determined to be ineligible for autologous stem cell transplant (ASCT).
At a median follow-up of 21 months, those treated with glofitamab combined with GemOx had a significantly higher median overall survival of 25.5 months, compared with those treated with the standard of care of rituximab and GemOx (12.9 months; hazard ratio [HR], 0.62; P = .006).
“The results show a 38% lower risk of death with the glofitamab plus GemOx, compared with [the rituximab regimen],” Dr. Abramson said.
Secondary endpoints showed consistent benefits with the glofitamab regimen, with significant improvements in progression-free survival and complete remission.
Unmet Need for Accessible Therapies
Relapsed/refractory DLBCL, the most common form of non-Hodgkin lymphoma (NHL) in the United States, is an aggressive blood cancer. The standard second-line therapy is high-dose chemotherapy followed by ASCT. However, factors including older age or coexisting medical conditions can compromise response, and those who relapse or are refractory to subsequent therapies have poor outcomes.
“Relapsed DLBCL in the second-line setting or later continues to represent an area of medical need,” Dr. Abramson said.
While several CD20xCD3 bispecific antibody drugs are under development to address the need, glofitamab was the first off-the-shelf, fixed-duration bispecific antibody to receive accelerated approval from the US Food and Drug Administration (FDA) for the treatment of R/R DLBCL, specifically as monotherapy after two or more lines of systemic therapy.
That approval was based on results from a pivotal phase 1/2 study, which showed high rates of deep and durable complete remission with the monotherapy.
To further evaluate glofitamab in combination with GemOx, the authors conducted the multicenter, open-label STARGLO trial, which extended enrollment to patients with just one prior therapy if they were determined to be stem cell transplant ineligible. Patients were also required to have an Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2.
Patients were randomized 2:1 either to treatment with glofitamab combined with GemOx, involving 8 cycles, in addition to 4 cycles of glofitamab monotherapy (n = 183), or to the rituximab plus GemOx regimen in 8 cycles (n = 91).
Overall, 153 (55.8%) of patients had primary refractory disease and 166 (60.6%) were refractory to their last therapy. The median age was 68, and 37% had two or more lines of therapy, including some who had received chimeric antigen receptor T-cell (CAR T) therapy (8.8% in the glofitamab group and 7.1% in the rituximab group).
In addition to the significant overall survival benefit, the glofitamab regimen also showed significantly improved progression-free survival at a median follow-up of 16.1 months, as observed by IRC-assessed PFS, with a median progression-free survival rate of 13.8 months vs 3.6 months (HR, 0.40; P < .0001).
The complete remission rate was doubled with glofitamab-GemOx, with a rate of 58.5% vs 25.3%, respectively; P < .0001.
Similar results were observed in subgroups, including relapsed vs refractory patients and those treated as a second or third line of care.
The median number of cycles received was higher among those receiving glofitamab (11 vs four cycles).
Adverse event (AE) rates were higher with glofitamab vs rituximab, including grade 3-4 AEs (69.4 vs 36.4%), grade 5 AEs (8.3 vs 4.5%; primarily driven by an imbalance of COVID-19 AEs), and serious AEs (54.4 vs 17.0%; primarily cytokine release syndrome [CRS]).
CRS was the most frequently reported AE in the glofitamab group (grade 1: 31.4%; grade 2: 10.5%; and grade 3: 2.3%), and events consistent with immune effector cell–associated neurotoxicity syndrome were reported in four patients (2.3%), all of which were concurrent with CRS.
Other AEs were consistent with the known risks associated with the therapy regimens.
“We found that with glofitamab GemOx, the toxicities were manageable, and the most common toxicity of CRS was predominantly low-grade and occurred with step-up dosing in cycle one and was completely reversible,” Dr. Abramson said.
He noted that the higher rate of grade 5 AEs with glofitamab GemOx “was far outweighed by the survival benefit for disease control.”
Overall, “these findings represent the best outcomes observed in a phase 3 trial for relapsed/refractory diffuse large B-cell lymphoma patients who are considered transplant ineligible,” Dr. Abramson said in an interview.
Improved Accessibility Vs CAR-T Therapy
Among key developments in the treatment of R/R DLBCL has been the advent and approval of potentially highly effective CAR T-cell therapy, with the anti-CD19 CAR T cell isiocabtagene maraleucel also FDA approved in the non–transplant eligible DLBCL second-line setting.
Asked in the press briefing about the role of glofitamab GemOx in relation to CAR T cell’s significant benefits, Dr. Abramson underscored the important limitations in CAR T-cell accessibility.
“What I would say is a rising tide lifts all boats,” he responded. “It’s great to have multiple effective immunotherapy strategies.”
However, “CAR T cells of course are not available to most people in the US or worldwide,” he explained.
“They are more difficult to access, they require lymphodepleting chemotherapy, and so ultimately, the majority of patients who could potentially benefit from a CAR T cell probably don’t have access to them in the first place.”
He noted that “the appeal of a regimen like [glofitamab] is that it is an off-the-shelf, targeted immunotherapy combined with a well-tolerated chemotherapy backbone and should be more broadly accessible outside of just tertiary care centers in major cities.”
Long-Term Durability?
Looking ahead, Dr. Abramson noted that a key issue of focus is how long the encouraging results actually last.
“The major ongoing question with this trial is the long-term durability of remissions,” he said.
“Thus far, with a median of 21 months of follow-up for overall survival, the results are encouraging but longer follow-up is needed,” he added.
“Further trials are needed in a broader large B-cell lymphoma population as this trial was limited to DLBCL not otherwise specified, so did not include patients with transformed lymphoma, primary mediastinal B-cell lymphoma, high grade B-cell lymphoma, etc.”
Is Chemo Necessary?
Commenting on the findings, Jonathan W. Friedberg, MD, director of the Wilmot Cancer Institute, University of Rochester School of Medicine, in Rochester, New York, underscored that, “given the overall survival benefit, these findings are clearly clinically significant.”
Noting that “these results add to evidence of high activity of bispecific antibodies in this disease,” Dr. Friedberg speculated on the role of chemotherapy with the therapy.
“Indeed, an important question in this study is whether the addition of chemotherapy to glofitamab is necessary, as high response rates with durable responses in patients who achieve complete remission have been demonstrated with single agent bispecific antibody therapy,” he said.
With the durability of CAR T therapy shown in long-term follow-up of trials to exceed 5 years, Dr. Friedberg added that “it is not known how bispecific antibody therapy, with or without chemotherapy, compares to CAR T-cell therapy and how to sequence CAR T and bispecific antibody therapy.”
Dr. Friedberg agreed that longer-term results are needed get a clearer, fuller picture of the therapy’s effects.
“I have no doubt that the overall survival benefit will endure, but in DLBCL our goal should be cure, and whether glofitamab cures as many patients as CAR T-cell therapy is not currently known and will require further follow-up of this and other trials.”
The study was sponsored by F. Hoffman-La Roche Ltd. Dr. Abramson reported ties with AbbVie, ADC Therapeutics, AstraZeneca, BeiGene, BMS, Cellectar, Caribou Biosciences, Celgene, Genentech, Gilead, Incyte, Interius, Janssen, Lilly, Novartis, F. Hoffmann-La Roche Ltd, Seagen, and Takeda. Dr. Friedberg had no disclosures.
“Glofitamab is the first CD20xCD3 bispecific antibody to demonstrate an overall survival benefit in DLBCL in a randomized phase 3 trial,” said first author Jeremy Abramson, MD, of the Massachusetts General Hospital Cancer Center, Boston, Massachusetts, in a press briefing at the annual meeting of the European Hematology Association (EHA) in Madrid.
“These results support the use of glofitamab GemOx as new, off-the-shelf treatment for relapsed/refractory DLBCL in patients who are transplant ineligible in the second-line or later setting,” he said.
The findings are from the phase 3 STARGLO study involving 274 patients with R/R DLBCL who had previously been treated either with at least two prior lines of therapy, or—if only one prior line of therapy—were determined to be ineligible for autologous stem cell transplant (ASCT).
At a median follow-up of 21 months, those treated with glofitamab combined with GemOx had a significantly higher median overall survival of 25.5 months, compared with those treated with the standard of care of rituximab and GemOx (12.9 months; hazard ratio [HR], 0.62; P = .006).
“The results show a 38% lower risk of death with the glofitamab plus GemOx, compared with [the rituximab regimen],” Dr. Abramson said.
Secondary endpoints showed consistent benefits with the glofitamab regimen, with significant improvements in progression-free survival and complete remission.
Unmet Need for Accessible Therapies
Relapsed/refractory DLBCL, the most common form of non-Hodgkin lymphoma (NHL) in the United States, is an aggressive blood cancer. The standard second-line therapy is high-dose chemotherapy followed by ASCT. However, factors including older age or coexisting medical conditions can compromise response, and those who relapse or are refractory to subsequent therapies have poor outcomes.
“Relapsed DLBCL in the second-line setting or later continues to represent an area of medical need,” Dr. Abramson said.
While several CD20xCD3 bispecific antibody drugs are under development to address the need, glofitamab was the first off-the-shelf, fixed-duration bispecific antibody to receive accelerated approval from the US Food and Drug Administration (FDA) for the treatment of R/R DLBCL, specifically as monotherapy after two or more lines of systemic therapy.
That approval was based on results from a pivotal phase 1/2 study, which showed high rates of deep and durable complete remission with the monotherapy.
To further evaluate glofitamab in combination with GemOx, the authors conducted the multicenter, open-label STARGLO trial, which extended enrollment to patients with just one prior therapy if they were determined to be stem cell transplant ineligible. Patients were also required to have an Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2.
Patients were randomized 2:1 either to treatment with glofitamab combined with GemOx, involving 8 cycles, in addition to 4 cycles of glofitamab monotherapy (n = 183), or to the rituximab plus GemOx regimen in 8 cycles (n = 91).
Overall, 153 (55.8%) of patients had primary refractory disease and 166 (60.6%) were refractory to their last therapy. The median age was 68, and 37% had two or more lines of therapy, including some who had received chimeric antigen receptor T-cell (CAR T) therapy (8.8% in the glofitamab group and 7.1% in the rituximab group).
In addition to the significant overall survival benefit, the glofitamab regimen also showed significantly improved progression-free survival at a median follow-up of 16.1 months, as observed by IRC-assessed PFS, with a median progression-free survival rate of 13.8 months vs 3.6 months (HR, 0.40; P < .0001).
The complete remission rate was doubled with glofitamab-GemOx, with a rate of 58.5% vs 25.3%, respectively; P < .0001.
Similar results were observed in subgroups, including relapsed vs refractory patients and those treated as a second or third line of care.
The median number of cycles received was higher among those receiving glofitamab (11 vs four cycles).
Adverse event (AE) rates were higher with glofitamab vs rituximab, including grade 3-4 AEs (69.4 vs 36.4%), grade 5 AEs (8.3 vs 4.5%; primarily driven by an imbalance of COVID-19 AEs), and serious AEs (54.4 vs 17.0%; primarily cytokine release syndrome [CRS]).
CRS was the most frequently reported AE in the glofitamab group (grade 1: 31.4%; grade 2: 10.5%; and grade 3: 2.3%), and events consistent with immune effector cell–associated neurotoxicity syndrome were reported in four patients (2.3%), all of which were concurrent with CRS.
Other AEs were consistent with the known risks associated with the therapy regimens.
“We found that with glofitamab GemOx, the toxicities were manageable, and the most common toxicity of CRS was predominantly low-grade and occurred with step-up dosing in cycle one and was completely reversible,” Dr. Abramson said.
He noted that the higher rate of grade 5 AEs with glofitamab GemOx “was far outweighed by the survival benefit for disease control.”
Overall, “these findings represent the best outcomes observed in a phase 3 trial for relapsed/refractory diffuse large B-cell lymphoma patients who are considered transplant ineligible,” Dr. Abramson said in an interview.
Improved Accessibility Vs CAR-T Therapy
Among key developments in the treatment of R/R DLBCL has been the advent and approval of potentially highly effective CAR T-cell therapy, with the anti-CD19 CAR T cell isiocabtagene maraleucel also FDA approved in the non–transplant eligible DLBCL second-line setting.
Asked in the press briefing about the role of glofitamab GemOx in relation to CAR T cell’s significant benefits, Dr. Abramson underscored the important limitations in CAR T-cell accessibility.
“What I would say is a rising tide lifts all boats,” he responded. “It’s great to have multiple effective immunotherapy strategies.”
However, “CAR T cells of course are not available to most people in the US or worldwide,” he explained.
“They are more difficult to access, they require lymphodepleting chemotherapy, and so ultimately, the majority of patients who could potentially benefit from a CAR T cell probably don’t have access to them in the first place.”
He noted that “the appeal of a regimen like [glofitamab] is that it is an off-the-shelf, targeted immunotherapy combined with a well-tolerated chemotherapy backbone and should be more broadly accessible outside of just tertiary care centers in major cities.”
Long-Term Durability?
Looking ahead, Dr. Abramson noted that a key issue of focus is how long the encouraging results actually last.
“The major ongoing question with this trial is the long-term durability of remissions,” he said.
“Thus far, with a median of 21 months of follow-up for overall survival, the results are encouraging but longer follow-up is needed,” he added.
“Further trials are needed in a broader large B-cell lymphoma population as this trial was limited to DLBCL not otherwise specified, so did not include patients with transformed lymphoma, primary mediastinal B-cell lymphoma, high grade B-cell lymphoma, etc.”
Is Chemo Necessary?
Commenting on the findings, Jonathan W. Friedberg, MD, director of the Wilmot Cancer Institute, University of Rochester School of Medicine, in Rochester, New York, underscored that, “given the overall survival benefit, these findings are clearly clinically significant.”
Noting that “these results add to evidence of high activity of bispecific antibodies in this disease,” Dr. Friedberg speculated on the role of chemotherapy with the therapy.
“Indeed, an important question in this study is whether the addition of chemotherapy to glofitamab is necessary, as high response rates with durable responses in patients who achieve complete remission have been demonstrated with single agent bispecific antibody therapy,” he said.
With the durability of CAR T therapy shown in long-term follow-up of trials to exceed 5 years, Dr. Friedberg added that “it is not known how bispecific antibody therapy, with or without chemotherapy, compares to CAR T-cell therapy and how to sequence CAR T and bispecific antibody therapy.”
Dr. Friedberg agreed that longer-term results are needed get a clearer, fuller picture of the therapy’s effects.
“I have no doubt that the overall survival benefit will endure, but in DLBCL our goal should be cure, and whether glofitamab cures as many patients as CAR T-cell therapy is not currently known and will require further follow-up of this and other trials.”
The study was sponsored by F. Hoffman-La Roche Ltd. Dr. Abramson reported ties with AbbVie, ADC Therapeutics, AstraZeneca, BeiGene, BMS, Cellectar, Caribou Biosciences, Celgene, Genentech, Gilead, Incyte, Interius, Janssen, Lilly, Novartis, F. Hoffmann-La Roche Ltd, Seagen, and Takeda. Dr. Friedberg had no disclosures.
FROM EHA 2024
APL: Should Chemo-Free Regimen Become New Standard?
“First-line therapy with ATRA-ATO with two initial doses of idarubicin results in superior event-free survival, compared to conventional ATRA-chemotherapy in patients with high-risk APL,” said first author Uwe Platzbecker, MD, of the University Hospital Leipzig, department for hematology, cellular therapy, hemostaseology, and infectious diseases, in Leipzig, Germany, at the annual meeting of the European Hematology Association (EHA) in Madrid, Spain.
“We believe that the trial may support the implementation of this regimen as a new standard of care in all patients with high-risk APL,” he said.
In the treatment of low and intermediate risk APL, a subtype of acute myeloid leukemia (AML), the combination of ATRA and ATO has become standard since being shown in a pivotal 2013 study to be superior versus ATRA and chemotherapy. The approach is approved by the Food and Drug Administration in the treatment of adults with newly diagnosed low-risk APL.
Importantly, the improved survival with ATRA/ATO approach may result from “reduced severe hematologic toxicity together with similar antileukemic efficacy,” compared with the regimen that include chemotherapy, the authors of the 2013 study speculated.
However, the treatment regimen has not been evaluated in randomized trials in patients with high-risk APL, defined as having a white blood cell count of more than 10,000 cells per μL.
For those patients, the conventional treatment remains ATRA with a chemotherapy backbone, Dr. Platzbecker explained.
To evaluate if the improvements extend to high-risk APL patients without compromising safety, Dr. Platzbecker and colleagues conducted the open-label, prospective APOLLO trial, involving newly diagnosed high-risk APL who were enrolled between 2016 and 2022 at 143 sites in six European countries.
The patients were randomized into one of two groups: ATRA/ATO, involving treatment consisting of two doses of idarubicin (12 mg/m2) on days 1 and 3 at the time of induction therapy, in addition to ATO 0.15 mg/kg and ATRA 45 mg/m2, daily until complete remission, or the ATRA-chemotherapy arm, involving standard ATRA also with idarubicin induction, followed by three cycles of chemotherapy-based consolidation as well as 2 years of maintenance treatment.
While the study was prematurely discontinued in August 2022 because of COVID-19–related recruitment delays and expiration of the study drug, the maintenance and observational periods are ongoing.
Of 131 patients with high-risk APL who were evaluable for the outcome analysis, 68 were in the ATRA/ATO group and 63 in the ATRA-chemotherapy arm.
Overall, participants had a mean age of 46, 50% were female, their median Eastern Cooperative Oncology Group score was 1. Their median white blood cell count was 36 × 109/L, with 39% having a white blood cell count greater than 50 × 109/L.
Molecular resistance occurred in 1.7% in the ATRA/ATO arm vs 5.5% in the ATRA chemotherapy arm, which was not statistically significant (P = .268); however, the incidence of molecular relapse was much lower without chemotherapy, at 1.6% with ATRA/ATO vs 14% with ATRA and chemotherapy.
For the primary endpoint, with a median follow-up of 31 months, the 2-year rate of event-free survival those in the ATRA/ATO arm was 88% vs 70% in the ATRA plus chemotherapy regimen (P = .02). The 5-year event-free survival continued to favor ATRA-ATO (87% vs 55%; P = .0034).
The estimated 5-year overall survival was 93% vs 82% for ATRA/ATO vs ATRA-chemotherapy, respectively, which was not significantly different (P = .17).
There were no significant differences between the arms in complete response (93% with ATRA/ATO vs 91% with ATRA-chemotherapy; P = .65), and rates of early death (within the first 30 days) were also similar across arms, at 7% vs 10%, respectively.
Death while in complete remission occurred in zero patients in the ATRA/ATO arm and three in the ATRA chemotherapy arm.
In terms of toxicities, the ATRA/ATO group had significantly lower rates of hematologic toxicity versus ATRA-chemotherapy, including rates of thrombocytopenia grade 1-4 and neutropenia grade 3-4 (P < .001), while there were no significant differences between the groups in hepatic toxicities (11.8% and 14.3%, respectively; P = .08) or differentiation syndrome (1.5% vs 4.8%; P = .27).
QTc prolongation grade 3-4 occurred in 4.4 patients receiving ATRA/ATO, compared with 0 in the ATRA-chemotherapy group; however, Dr. Platzbecker said the cases had no clinical implications.
Asked to elaborate on the regimens’ toxicities in the press briefing, Dr. Platzbecker noted that “what is very important especially for patients, is [lower rates] of issues such as hair loss and constipation that are much less common with the ATRO/ATO regimen.”
“In addition, we know from the early experiences with this that younger patients are being cured by this regimen,” hence improving pregnancy prospects for women.
A take-home message from the overall results is that the ATRO/ATO regimen for high-risk APL patients should represent “a new treatment paradigm” that will “hopefully soon” be reflected in guideline recommendations, Dr. Platzbecker said in an interview.
Concerns Included Relapse, Differentiation Syndrome
Commenting on the research, Mikkael A. Sekeres, MD, explained that, while the “less is more” non-chemotherapy approach was adopted in widespread utilization in low-risk APL because of superior outcomes, a variety of concerns surrounded its use in high-risk patients.
“In high-risk patients, there were concerns that a durable response would be lower and that relapse would be higher for patients receiving ATRA and ATO than those receiving standard chemotherapy,” Dr. Sekeres, who is chief of the division of hematology, department of medicine, Sylvester Comprehensive Cancer Center, University of Miami, Miami, Florida, said in an interview.
“In addition, it was theoretically possible that patients receiving the differentiating agents ATRA and ATO could suffer higher rates of differentiation syndrome, which could contribute to early death,” he explained. “These fears were simply not realized in the trial.”
Caveats of the trial “include the relatively small sample size and that the trial was stopped prematurely due to low enrollment during the COVID pandemic,” he noted.
Another limitation was the median follow-up of about 2.5 years.
However, Dr. Sekeres said he agreed that, “with further follow-up and continued superiority of the idarubicin, ATRA, and ATO combination, this could become a new standard of care for high-risk patients with APL.”
Dr. Platzbecker’s disclosures include ties with Teva, BMS, Curis, Janssen, AbbVie, and Takeda. Dr. Sekeres had no disclosures.
“First-line therapy with ATRA-ATO with two initial doses of idarubicin results in superior event-free survival, compared to conventional ATRA-chemotherapy in patients with high-risk APL,” said first author Uwe Platzbecker, MD, of the University Hospital Leipzig, department for hematology, cellular therapy, hemostaseology, and infectious diseases, in Leipzig, Germany, at the annual meeting of the European Hematology Association (EHA) in Madrid, Spain.
“We believe that the trial may support the implementation of this regimen as a new standard of care in all patients with high-risk APL,” he said.
In the treatment of low and intermediate risk APL, a subtype of acute myeloid leukemia (AML), the combination of ATRA and ATO has become standard since being shown in a pivotal 2013 study to be superior versus ATRA and chemotherapy. The approach is approved by the Food and Drug Administration in the treatment of adults with newly diagnosed low-risk APL.
Importantly, the improved survival with ATRA/ATO approach may result from “reduced severe hematologic toxicity together with similar antileukemic efficacy,” compared with the regimen that include chemotherapy, the authors of the 2013 study speculated.
However, the treatment regimen has not been evaluated in randomized trials in patients with high-risk APL, defined as having a white blood cell count of more than 10,000 cells per μL.
For those patients, the conventional treatment remains ATRA with a chemotherapy backbone, Dr. Platzbecker explained.
To evaluate if the improvements extend to high-risk APL patients without compromising safety, Dr. Platzbecker and colleagues conducted the open-label, prospective APOLLO trial, involving newly diagnosed high-risk APL who were enrolled between 2016 and 2022 at 143 sites in six European countries.
The patients were randomized into one of two groups: ATRA/ATO, involving treatment consisting of two doses of idarubicin (12 mg/m2) on days 1 and 3 at the time of induction therapy, in addition to ATO 0.15 mg/kg and ATRA 45 mg/m2, daily until complete remission, or the ATRA-chemotherapy arm, involving standard ATRA also with idarubicin induction, followed by three cycles of chemotherapy-based consolidation as well as 2 years of maintenance treatment.
While the study was prematurely discontinued in August 2022 because of COVID-19–related recruitment delays and expiration of the study drug, the maintenance and observational periods are ongoing.
Of 131 patients with high-risk APL who were evaluable for the outcome analysis, 68 were in the ATRA/ATO group and 63 in the ATRA-chemotherapy arm.
Overall, participants had a mean age of 46, 50% were female, their median Eastern Cooperative Oncology Group score was 1. Their median white blood cell count was 36 × 109/L, with 39% having a white blood cell count greater than 50 × 109/L.
Molecular resistance occurred in 1.7% in the ATRA/ATO arm vs 5.5% in the ATRA chemotherapy arm, which was not statistically significant (P = .268); however, the incidence of molecular relapse was much lower without chemotherapy, at 1.6% with ATRA/ATO vs 14% with ATRA and chemotherapy.
For the primary endpoint, with a median follow-up of 31 months, the 2-year rate of event-free survival those in the ATRA/ATO arm was 88% vs 70% in the ATRA plus chemotherapy regimen (P = .02). The 5-year event-free survival continued to favor ATRA-ATO (87% vs 55%; P = .0034).
The estimated 5-year overall survival was 93% vs 82% for ATRA/ATO vs ATRA-chemotherapy, respectively, which was not significantly different (P = .17).
There were no significant differences between the arms in complete response (93% with ATRA/ATO vs 91% with ATRA-chemotherapy; P = .65), and rates of early death (within the first 30 days) were also similar across arms, at 7% vs 10%, respectively.
Death while in complete remission occurred in zero patients in the ATRA/ATO arm and three in the ATRA chemotherapy arm.
In terms of toxicities, the ATRA/ATO group had significantly lower rates of hematologic toxicity versus ATRA-chemotherapy, including rates of thrombocytopenia grade 1-4 and neutropenia grade 3-4 (P < .001), while there were no significant differences between the groups in hepatic toxicities (11.8% and 14.3%, respectively; P = .08) or differentiation syndrome (1.5% vs 4.8%; P = .27).
QTc prolongation grade 3-4 occurred in 4.4 patients receiving ATRA/ATO, compared with 0 in the ATRA-chemotherapy group; however, Dr. Platzbecker said the cases had no clinical implications.
Asked to elaborate on the regimens’ toxicities in the press briefing, Dr. Platzbecker noted that “what is very important especially for patients, is [lower rates] of issues such as hair loss and constipation that are much less common with the ATRO/ATO regimen.”
“In addition, we know from the early experiences with this that younger patients are being cured by this regimen,” hence improving pregnancy prospects for women.
A take-home message from the overall results is that the ATRO/ATO regimen for high-risk APL patients should represent “a new treatment paradigm” that will “hopefully soon” be reflected in guideline recommendations, Dr. Platzbecker said in an interview.
Concerns Included Relapse, Differentiation Syndrome
Commenting on the research, Mikkael A. Sekeres, MD, explained that, while the “less is more” non-chemotherapy approach was adopted in widespread utilization in low-risk APL because of superior outcomes, a variety of concerns surrounded its use in high-risk patients.
“In high-risk patients, there were concerns that a durable response would be lower and that relapse would be higher for patients receiving ATRA and ATO than those receiving standard chemotherapy,” Dr. Sekeres, who is chief of the division of hematology, department of medicine, Sylvester Comprehensive Cancer Center, University of Miami, Miami, Florida, said in an interview.
“In addition, it was theoretically possible that patients receiving the differentiating agents ATRA and ATO could suffer higher rates of differentiation syndrome, which could contribute to early death,” he explained. “These fears were simply not realized in the trial.”
Caveats of the trial “include the relatively small sample size and that the trial was stopped prematurely due to low enrollment during the COVID pandemic,” he noted.
Another limitation was the median follow-up of about 2.5 years.
However, Dr. Sekeres said he agreed that, “with further follow-up and continued superiority of the idarubicin, ATRA, and ATO combination, this could become a new standard of care for high-risk patients with APL.”
Dr. Platzbecker’s disclosures include ties with Teva, BMS, Curis, Janssen, AbbVie, and Takeda. Dr. Sekeres had no disclosures.
“First-line therapy with ATRA-ATO with two initial doses of idarubicin results in superior event-free survival, compared to conventional ATRA-chemotherapy in patients with high-risk APL,” said first author Uwe Platzbecker, MD, of the University Hospital Leipzig, department for hematology, cellular therapy, hemostaseology, and infectious diseases, in Leipzig, Germany, at the annual meeting of the European Hematology Association (EHA) in Madrid, Spain.
“We believe that the trial may support the implementation of this regimen as a new standard of care in all patients with high-risk APL,” he said.
In the treatment of low and intermediate risk APL, a subtype of acute myeloid leukemia (AML), the combination of ATRA and ATO has become standard since being shown in a pivotal 2013 study to be superior versus ATRA and chemotherapy. The approach is approved by the Food and Drug Administration in the treatment of adults with newly diagnosed low-risk APL.
Importantly, the improved survival with ATRA/ATO approach may result from “reduced severe hematologic toxicity together with similar antileukemic efficacy,” compared with the regimen that include chemotherapy, the authors of the 2013 study speculated.
However, the treatment regimen has not been evaluated in randomized trials in patients with high-risk APL, defined as having a white blood cell count of more than 10,000 cells per μL.
For those patients, the conventional treatment remains ATRA with a chemotherapy backbone, Dr. Platzbecker explained.
To evaluate if the improvements extend to high-risk APL patients without compromising safety, Dr. Platzbecker and colleagues conducted the open-label, prospective APOLLO trial, involving newly diagnosed high-risk APL who were enrolled between 2016 and 2022 at 143 sites in six European countries.
The patients were randomized into one of two groups: ATRA/ATO, involving treatment consisting of two doses of idarubicin (12 mg/m2) on days 1 and 3 at the time of induction therapy, in addition to ATO 0.15 mg/kg and ATRA 45 mg/m2, daily until complete remission, or the ATRA-chemotherapy arm, involving standard ATRA also with idarubicin induction, followed by three cycles of chemotherapy-based consolidation as well as 2 years of maintenance treatment.
While the study was prematurely discontinued in August 2022 because of COVID-19–related recruitment delays and expiration of the study drug, the maintenance and observational periods are ongoing.
Of 131 patients with high-risk APL who were evaluable for the outcome analysis, 68 were in the ATRA/ATO group and 63 in the ATRA-chemotherapy arm.
Overall, participants had a mean age of 46, 50% were female, their median Eastern Cooperative Oncology Group score was 1. Their median white blood cell count was 36 × 109/L, with 39% having a white blood cell count greater than 50 × 109/L.
Molecular resistance occurred in 1.7% in the ATRA/ATO arm vs 5.5% in the ATRA chemotherapy arm, which was not statistically significant (P = .268); however, the incidence of molecular relapse was much lower without chemotherapy, at 1.6% with ATRA/ATO vs 14% with ATRA and chemotherapy.
For the primary endpoint, with a median follow-up of 31 months, the 2-year rate of event-free survival those in the ATRA/ATO arm was 88% vs 70% in the ATRA plus chemotherapy regimen (P = .02). The 5-year event-free survival continued to favor ATRA-ATO (87% vs 55%; P = .0034).
The estimated 5-year overall survival was 93% vs 82% for ATRA/ATO vs ATRA-chemotherapy, respectively, which was not significantly different (P = .17).
There were no significant differences between the arms in complete response (93% with ATRA/ATO vs 91% with ATRA-chemotherapy; P = .65), and rates of early death (within the first 30 days) were also similar across arms, at 7% vs 10%, respectively.
Death while in complete remission occurred in zero patients in the ATRA/ATO arm and three in the ATRA chemotherapy arm.
In terms of toxicities, the ATRA/ATO group had significantly lower rates of hematologic toxicity versus ATRA-chemotherapy, including rates of thrombocytopenia grade 1-4 and neutropenia grade 3-4 (P < .001), while there were no significant differences between the groups in hepatic toxicities (11.8% and 14.3%, respectively; P = .08) or differentiation syndrome (1.5% vs 4.8%; P = .27).
QTc prolongation grade 3-4 occurred in 4.4 patients receiving ATRA/ATO, compared with 0 in the ATRA-chemotherapy group; however, Dr. Platzbecker said the cases had no clinical implications.
Asked to elaborate on the regimens’ toxicities in the press briefing, Dr. Platzbecker noted that “what is very important especially for patients, is [lower rates] of issues such as hair loss and constipation that are much less common with the ATRO/ATO regimen.”
“In addition, we know from the early experiences with this that younger patients are being cured by this regimen,” hence improving pregnancy prospects for women.
A take-home message from the overall results is that the ATRO/ATO regimen for high-risk APL patients should represent “a new treatment paradigm” that will “hopefully soon” be reflected in guideline recommendations, Dr. Platzbecker said in an interview.
Concerns Included Relapse, Differentiation Syndrome
Commenting on the research, Mikkael A. Sekeres, MD, explained that, while the “less is more” non-chemotherapy approach was adopted in widespread utilization in low-risk APL because of superior outcomes, a variety of concerns surrounded its use in high-risk patients.
“In high-risk patients, there were concerns that a durable response would be lower and that relapse would be higher for patients receiving ATRA and ATO than those receiving standard chemotherapy,” Dr. Sekeres, who is chief of the division of hematology, department of medicine, Sylvester Comprehensive Cancer Center, University of Miami, Miami, Florida, said in an interview.
“In addition, it was theoretically possible that patients receiving the differentiating agents ATRA and ATO could suffer higher rates of differentiation syndrome, which could contribute to early death,” he explained. “These fears were simply not realized in the trial.”
Caveats of the trial “include the relatively small sample size and that the trial was stopped prematurely due to low enrollment during the COVID pandemic,” he noted.
Another limitation was the median follow-up of about 2.5 years.
However, Dr. Sekeres said he agreed that, “with further follow-up and continued superiority of the idarubicin, ATRA, and ATO combination, this could become a new standard of care for high-risk patients with APL.”
Dr. Platzbecker’s disclosures include ties with Teva, BMS, Curis, Janssen, AbbVie, and Takeda. Dr. Sekeres had no disclosures.
FROM EHA 2024