Efficacy and safety of idecabtagene vicleucel in patients with relapsed-refractory multiple myeloma not meeting the KarMMa-1 trial eligibility criteria: A real-world multicentre study

Ide-cel received approval for relapsed-refractory multiple myeloma based on the results of the KarMMa-1 trial. However, patients with significant comorbidities, aggressive disease and prior B-cell maturation antigen-directed therapy (BCMA-DT) were excluded. This retrospective study evaluated real-world outcomes of patients who did not meet the KarMMa-1 eligibility criteria and were treated with standard of care (SOC) ide-cel. A total of 69 patients from three US centres who did not meet the KarMMa-1 criteria underwent ide-cel infusion. The main reasons for trial ineligibility included baseline grade 3-4 cytopenia (39%), prior BCMA-DT (26%), renal impairment (19%) and Eastern Cooperative Oncology Group performance status ≥2 (14.5%). Cytokine-release syndrome occurred in 81% vs. 84%, and immune effector cell-associated neurotoxicity syndrome occurred in 28% vs. 18% of SOC versus KarMMa-1 patients, respectively. Early infection (≤8 weeks post-infusion) and severe infection rates were 42% vs. 49% and 30% vs. 22% for the SOC versus KarMMa-1 cohorts, respectively. Grade 3-4 cytopenias for SOC versus KarMMa-1 cohorts were: neutropenia (87% vs. 89%), anaemia (51% vs. 60%) and thrombocytopenia (65% vs. 52%). Overall response rate was higher for the SOC cohort (93% vs. 73%), as was the complete response or better rate (48% vs. 33%). However, median progression-free survival and overall survival were comparable between the two groups. Our findings support broadening the inclusion criteria of future trials evaluating ide-cel.