Isatuximab-Based Therapy Shows Sustained Efficacy Across Age Groups in Transplant-Ineligible Multiple Myeloma
核心洞察
Long-term data from the BENEFIT trial demonstrates that isatuximab plus lenalidomide, dexamethasone, and bortezomib (Isa-VRd) achieves significantly higher sustained minimal residual disease negativity rates compared to Isa-Rd in transplant-ineligible newly diagnosed multiple myeloma (搜索) patients.
A pooled analysis of 336 patients from the IMROZ study confirms that Isa-VRd maintains consistent efficacy across age groups, with overall response rates exceeding 92% in both patients under and over 75 years of age.
The treatment regimen shows robust performance in challenging patient populations, including frail patients, though slightly reduced response rates and higher adverse event rates are observed in this subgroup.
New research presented at the 67th American Society of Hematology Annual Meeting demonstrates that isatuximab-based combination therapy maintains robust efficacy across diverse patient populations with newly diagnosed multiple myeloma (搜索) (NDMM) who are ineligible for transplant. Two complementary studies provide compelling evidence for the broad applicability of the isatuximab, lenalidomide, dexamethasone, and bortezomib (Isa-VRd) regimen as a new standard of care.
Sustained Minimal Residual Disease Benefits Confirmed
Long-term follow-up data from the phase 3 BENEFIT trial (NCT04751877) reveals significant improvements in sustained minimal residual disease (sMRD) negativity with Isa-VRd compared to the regimen without bortezomib (Isa-Rd). After a median follow-up of 33.4 months (95% CI, 33.0–34.0), the sMRD negativity rate at the 10-5 threshold was significantly higher in the Isa-VRd arm (OR = 2.26; 95% CI, 1.50–4.80; P = .0007) at 24 months.
"It's becoming increasingly clear that a single MRD assessment is not always sufficient to predict long-term outcomes," said Arthur Bobin, MD, an investigator of the study and hematologist at Poitiers University Hospital in Poitiers, France. The sustained nature of MRD negativity provides stronger prognostic value than single-point assessments, with improved progression-free survival and prognostic granularity for patients maintaining negative status over 6 or 12 months.
Challenging Patient Subgroups Show Consistent Response
The analysis specifically examined patients with the t(11;14) translocation, the most common primary event in multiple myeloma (搜索) that represents a unique subset of disease with higher levels of BCL2 (搜索) and more frequent CD20 (搜索) expression. While MRD negativity rates were consistently lower in this subgroup at all time points up to 24 months, the pattern was similar to observations in the phase 3 MIDAS study.
"This patient may require more prolonged exposure or maybe a stronger treatment to achieve MRD negativity," Bobin explained, noting that patients with t(11;14) translocations can experience delays in improvements and may respond more slowly to treatment.
Efficacy Maintained Across Age and Frailty Groups
A comprehensive pooled analysis of 336 patients from the IMROZ study (NCT03319667) and a phase 1b study (TCD13983) examined Isa-VRd effectiveness across age and frailty subgroups. The median age was 71 years, ranging from 49 to 87 years, with patients stratified by baseline age (<75 years, n=271; and ≥75 years, n=65) and frailty status using the simplified International Myeloma Working Group score.
Median progression-free survival was not reached in the overall population or in either age subgroup, demonstrating consistent efficacy across all analyzed groups. Overall response rates were remarkably high and comparable between age groups: 93% for patients aged 75 years or younger and 92.3% for those older than 75. High rates of complete response or better were achieved in both cohorts (72% and 67.7%, respectively).
Deep Response Rates Demonstrate Treatment Durability
Central laboratory testing revealed MRD negativity rates at the 10-5 sensitivity level that were similar between age cohorts: 53.5% in the 75 years or younger group and 50.8% in the group older than 75 years. The rates of 24-month sustained MRD negativity were 32.8% for the younger cohort and 23.1% for the older cohort.
When examining frailty impact, sustained 24-month MRD-negative rates were 34.9% for nonfrail and 20.5% for frail patients aged 75 or younger. For patients over 75 years, nonfrail individuals demonstrated a 34.8% sustained MRD negativity rate compared to 16.7% for frail patients.
Safety Profile Reflects Patient Population Challenges
The treatment was generally well tolerated, though safety analysis reflected the increased clinical challenges in elderly and frail populations. Rates of grade 3 or higher treatment-emergent adverse events were slightly higher in older patients (95.4% in patients aged >75 years) compared to younger patients (87.8% in patients aged <75 years).
More significant differences were noted in serious adverse events, occurring in 73.8% of patients older than 75 years and 66.8% of patients 75 years or younger. Within the younger group, frail patients experienced serious adverse events at a notably higher rate (81.6%) than nonfrail patients (64.4%). Treatment discontinuation due to adverse events was higher in frail patients: 31.6% for frail patients in the younger group and 28.6% for frail patients in the older cohort.
Clinical Implications for Standard of Care
At the new follow-up point, 78 patients (29%) had discontinued treatment, mainly due to progressive disease. Importantly, no new safety signals were observed in either treatment arm, including in high-risk patients. The safety profile remained positive with no increase in treatment-emergent adverse events compared with Isa-Rd.
"The data provide an important treatment option for frontline disease control and reinforce Isa-VRd as a new standard of care for TI NDMM," Bobin concluded. "sMRD is a powerful longitudinal marker for disease control."
The comprehensive evidence supports the use of Isa-VRd as a new standard of care for patients with transplant-ineligible NDMM, particularly those at older age or with high-risk disease, providing clinicians with a robust treatment option that maintains efficacy across diverse patient populations.