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

Summary 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.