A new analysis from the FUMANBA-1 study indicates that a full lymphodepletion dose prior to infusion of Equecabtagene Autoleucel (Eque-cel, Fucaso™) significantly improves treatment outcomes for patients with relapsed/refractory multiple myeloma (R/R MM). The findings, presented at the 2024 International Myeloma Society (IMS) Annual Meeting, highlight the importance of optimal lymphodepletion in maximizing the efficacy of CAR-T cell therapy without increasing toxicity.
The post-hoc analysis included 91 subjects with R/R MM who had not previously received CAR-T therapy. Patients were divided into two groups: a standard-dose lymphodepletion group (n=58) and a dose-adjusted lymphodepletion group (n=33). Baseline characteristics were similar between the groups, including age range, physical fitness scores, tumor staging, high-risk cytogenetic abnormalities, and previous lines of treatment. The median follow-up period was 18.07 months.
Efficacy Outcomes
The standard-dose group demonstrated superior efficacy outcomes compared to the dose-adjusted group. The overall response rate (ORR) was 100% in the standard-dose group and 97% in the dose-adjusted group. The stringent complete remission rate (sCR) was 82.8% and 78.8%, respectively. Notably, 92.2% of patients in the standard-dose group maintained a duration of response (DOR) exceeding one year, compared to 70.6% in the dose-adjusted group.
Minimal residual disease (MRD) negativity, a key indicator of treatment depth, was also significantly better in the standard-dose group. The median time to achieve MRD negativity was 15 days in the standard-dose group versus 22 days in the dose-adjusted group. The 12-month MRD negativity rate was 90.4% in the standard-dose group, significantly higher than the 63.7% observed in the dose-adjusted group (HR=3.33, P=0.0166).
Progression-free survival (PFS) also favored the standard-dose group. The 12-month PFS rate was 92.2% in the standard-dose group, with a median PFS not yet reached, compared to 73.5% and 30.28 months, respectively, in the dose-adjusted group (HR=3.64, P=0.0032).
Safety Profile
Importantly, the study found no significant differences in the severity and incidence of cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) between the two groups. CRS (grades 1-2) occurred in 94.8% of the standard dose group and 93.9% of the dose-adjusted group, with no severe CRS (≥grade 3) in either group. Only one grade 2 ICANS case was reported in the adjusted group, with no ICANS (≥grade 3) occurring in either group.
Expert Commentary
"The lymphodepletion regimen is crucial for CAR-T cell therapy," stated Professor Lugui Qiu, from the Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, and Professor Chunrui Li, from Tongji Hospital, Tongji Medical College, Huazhong University of Science & Technology. "Data from this study indicate that standardized and sufficient lymphodepletion can lead to a higher quality of remission and more ideal clearance of minimal residual disease without increasing the potential of adverse reactions."
Dr. Yongke Zhang, Chief Scientific Officer of IASO Bio, added, "This study demonstrated the critical role of standard lymphodepletion in enhancing treatment outcomes and prognosis for patients... these findings will contribute significantly to the establishment and optimization of lymphodepletion preconditioning standards in the field of CAR-T cell therapy."
