CARTITUDE-2 UPDATE: CILTACABTAGENE AUTOLEUCEL, A B-CELL MATURATION ANTIGEN-DIRECTED CHIMERIC ANTIGEN RECEPTOR T-CELL THERAPY, IN LENALIDOMIDEREFRACTORY PATIENTS WITH PROGRESSIVE MULTIPLE MYELOMA AFTER 1-3 PRIOR LINES OF THERAPY

ABSTRACT

Introduction: Ciltacabtagene autoleucel (cilta-cel) is a chimeric antigen receptor T-cell (CAR-T) therapy expressing two B-cell maturation antigen (BCMA)-targeting, single-domain antibodies. The multicohort, open-label, phase 2 CARTITUDE-2 study (NCT04133636) is assessing cilta-cel in patients (pts) with multiple myeloma (MM) under various clinical settings and evaluating the suitability of outpatient administration. Updated results of CARTITUDE-2 cohort A are presented here. Methods: Cohort A pts had progressive MM after 1-3 prior lines of therapy (LOT;included proteasome inhibitor [PI] and immunomodulatory drug [IMiD]), were lenalidomide-refractory, and had no previous exposure to BCMA-targeting agents. A single cilta-cel infusion at a target dose of 0.75×106 CAR+ viable T cells/kg was given 5-7 d after start of lymphodepletion (cyclophosphamide [300 mg/m2] and fludarabine [30 mg/m2] for 3 d). The primary endpoint was minimal residual disease (MRD) negativity at 10-5 at any time point. Secondary endpoints were overall response rate (ORR), duration of response (DOR), time and duration of MRD negativity, and incidence and severity of adverse events (AEs). Response was assessed per International Myeloma Working Group criteria and AEs were graded by Common Terminology Criteria for Adverse Events version 5.0 (cytokine release syndrome [CRS] and immune effector cell-associated neurotoxicity syndrome [ICANS] by American Society for Transplantation and Cellular Therapy). Results: As of April 15, 2021 (median follow-up of 9.7 mo), 20 pts (65% men;median age 60 y [range 38-75]) received cilta-cel, with 1 pt treated in an outpatient setting. Pts had a median of 2 prior LOT (range 1-3);60% had 1-2 prior LOT and 40% had 3 prior LOT. All pts were exposed to a PI, IMiD, and dexamethasone;95% were exposed to alkylating agents and 65% to daratumumab. 95% of pts were refractory to last LOT;40% were triple-class refractory. ORR was 95% (95% CI 75.1-99.9);85% (95% CI 62.1-96.8) had ≥complete response (CR), and 95% (95% CI 75.1-99.9) had ≥very good partial response (Figure). Median time to first response was 1.0 mo (range 0.7-3.3) and median time to ≥CR was 2.6 mo (range 0.9-7.9). Median DOR was not reached;progression-free survival (PFS) at 6 mo was 90% (95% CI 65.6-97.4). Of 13 MRD-evaluable pts, 92.3% (95% CI 64.0-99.8) were MRD-negative at 10-5. Hematologic AEs (≥20% of pts) were neutropenia (95%;grade [gr] 3/4 95%), thrombocytopenia (80%;gr 3/4 35%), anemia (75%;gr 3/4 45%), lymphopenia (65%;gr 3/4 60%) and leukopenia (55%;gr 3/4 55%). 95% of pts had CRS (gr 3/4 10%);median time to onset was 7 d (range 5-9) and median duration was 4 d (range 2-11). Four pts (20%) had CAR-T neurotoxicity (all gr 1/2). Three pts (15%) had ICANS (all gr 1/2);median time to onset was 8 d (range 7-10) and median duration was 3 d (range 1-3). One pt had facial paralysis (gr 2) with time to onset of 29 d and duration of 51 d. No movement and neurocognitive treatment-emergent adverse events (TEAEs) were reported. One death due to COVID-19 was assessed as treatment-related. Safety was manageable in the pt treated in an outpatient setting. Conclusions: A single cilta-cel infusion led to early and deep responses in pts with MM who had 1-3 prior LOT and were lenalidomide-refractory. No movement and neurocognitive TEAEs occurred, suggesting successful implementation of monitoring and pt management strategies across phase 2/3 studies in the CARTITUDE program.