Aim:To compare the efficacy of idecabtagene vicleucel (ide-cel, bb2121) versus conventional care (CC) in triple-class exposed relapsed and refractory multiple myeloma (RRMM) patients. Patients & methods:A matching-adjusted indirect comparison was conducted using individual patient-level data from the pivotal, phase II, single-arm KarMMa trial (NCT03361748) and aggregate-level data from MAMMOTH, the largest independent observational study of CC in heavily pretreated RRMM patients. Results:Ide-cel improved overall response rate (odds ratio: 5.30; 95% CI: 2.96–9.51), progression-free survival (hazard ratio: 0.50; 95% CI: 0.36–0.70) and overall survival (hazard ratio: 0.37; 95% CI: 0.25–0.56) versus CC. Conclusion:These results suggest ide-cel offers improvements in clinical outcomes relative to CC in this heavily pretreated RRMM population.