Rodriguez-Otero, Paula

Abstract Idecabtagene vicleucel (ide-cel) is a chimeric antigen receptor (CAR) T-cell therapy approved for relapsed and refractory multiple myeloma (RRMM). Out-of-specification (OOS) CAR T cells not meeting criteria for commercial release are considered an investigational product; the expanded access protocol (EAP) allows release of OOS product for administration. The manufacturing analysis of capability, reliability, and timely delivery of ide-cel in the United States over >3 years since its approval included patients with RRMM who underwent leukapheresis for ide-cel treatment after ≥2 prior lines of therapy between 23 February 2021 and 1 November 2024. Additionally, the BB2121-EAP-001 study evaluated safety and efficacy of OOS ide-cel and included patients who had undergone leukapheresis for commercial ide-cel treatment not meeting commercial release specifications, most commonly due to high CD137 activation or low-infused dose. Primary end point was safety. Secondary end points were overall response rate (ORR) and complete response rate (CRR). At data cutoff (1 November 2024), the manufacturing success rate of ide-cel improved from 95.3% in 2021 to 96.8% in 2024. Turnaround time also improved from 31 days in 2021 to 24 days in 2024. In BB2121-EAP-001, 68 (72.3%) patients experienced ≥1 cytokine release syndrome event (mostly grade 1/2) and 15 (16.0%) had neurological toxicities (2 grade 3, 13 grade 1/2). ORR was 75.4% (95% confidence interval [CI], 63.1-85.2), and CRR was 35.4% (95% CI, 23.9-48.2). The manufacturing success of ide-cel is reliable and consistently high, and when OOS ide-cel products emerged, they demonstrated consistent clinical efficacy and safety. The BB2121-EAP-001 study was registered at www.clinicaltrials.gov as NCT04771078.

PURPOSE This analysis aimed to contextualize the symptoms of peripheral neuropathy (PN) experienced by patients with triple-class refractory (TCR) multiple myeloma (MM) treated with elranatamab in the MagnetisMM-3 clinical trial with those experienced by patients with TCR MM receiving a new line of physician's choice of therapy in the real-world MagnetisMM-14 study. METHODS MagnetisMM-3 included 123 patients and MagnetisMM-14 included 35 who had TCR MM and were enrolled under the same eligibility criteria. Patient-reported symptoms of PN were collected monthly using the Chemotherapy-Induced Peripheral Neuropathy-20 item (CIPN20) questionnaire and compared for clinically meaningful differences across sensory, motor, and autonomic domains. Higher scores indicated worse patient-reported PN symptoms. RESULTS Baseline demographics and clinical characteristics for patients in MagnetisMM-3 and MagnetisMM-14 were generally similar. Patients in MagnetisMM-3 had a median of five ( v four in MagnetisMM-14) prior lines of therapy. In MagnetisMM-14, common index therapies included elotuzumab + pomalidomide (23%), carfilzomib + pomalidomide (19%), or carfilzomib + cyclophosphamide (19%), all with corticosteroids. Mean scores for sensory (15.8 v 14.8) and motor (14.4 v 12.2) domains of the CIPN20 were similar between MagnetisMM-3 and MagnetisMM-14 at baseline. Mean scores for the autonomic domain were 14.0 versus 21.3 at baseline, respectively. No clinically meaningful differences for any domain were found between month 6 scores or changes in scores from baseline to month 6 between MagnetisMM-3 and MagnetisMM-14 populations. CONCLUSION These findings suggest that elranatamab treatment was not associated with a worsening of patient-reported PN symptoms across the sensory, motor, and autonomic domains of the CIPN20. Moreover, PN symptoms reported with elranatamab treatment were similar to those reported with other common therapies used in real-world clinical practice for the management of MM. MagnetisMM-3 ClinicalTrials.gov identifier: NCT04649359 .

Abstract Outcomes are poor in triple-class–exposed (TCE) relapsed and refractory multiple myeloma (R/RMM). In the phase 3 KarMMa-3 trial, patients with TCE R/RMM and 2 to 4 prior regimens were randomized 2:1 to idecabtagene vicleucel (ide-cel) or standard regimens (SRs). An interim analysis (IA) demonstrated significantly longer median progression-free survival (PFS; primary end point; 13.3 vs 4.4 months; P < .0001) and higher overall response rate (ORR) with ide-cel vs SRs. At final PFS analysis (median follow-up, 30.9 months), ide-cel further improved median PFS vs SRs (13.8 vs 4.4 months; hazard ratio [HR], 0.49; 95% confidence interval [CI], 0.38-0.63). PFS benefit with ide-cel vs SRs was observed regardless of number of prior lines of therapy, with greatest benefit after 2 prior lines (16.2 vs 4.8 months, respectively). ORR benefit was maintained with ide-cel vs SRs (71% vs 42%; complete response, 44% vs 5%). Patient-centric design allowed crossover from SRs (56%) to ide-cel upon progressive disease, confounding overall survival (OS) interpretation. At IA of OS, median was 41.4 (95% CI, 30.9 to not reached [NR]) vs 37.9 (95% CI, 23.4 to NR) months with ide-cel and SRs, respectively (HR, 1.01; 95% CI, 0.73-1.40); median OS in both arms was longer than historical data (9-22 months). Two prespecified analyses adjusting for crossover showed OS favoring ide-cel. This trial highlighted the importance of individualized bridging therapy to ensure adequate disease control during ide-cel manufacturing. Ide-cel improved patient-reported outcomes vs SRs. No new safety signals were reported. These results demonstrate the continued favorable benefit-risk profile of ide-cel in early-line and TCE R/RMM. This trial was registered at www.ClinicalTrials.gov as #NCT03651128.