Comparative efficacy of ciltacabtagene autoleucel versus idecabtagene vicleucel in the treatment of patients with relapsed or refractory multiple myeloma previously treated with 2-4 prior lines of therapy: a matching-adjusted indirect comparison

Objective: To estimate the comparative efficacy of ciltacabtagene autoleucel (cilta-cel) versus idecabtagene vicleucel (ide-cel) in patients with relapsed/refractory multiple myeloma (RRMM) treated with 2-4 prior lines of therapy. Methods: Matching adjusted indirect comparison (MAICs) were performed using individual patient-level data (IPD) for cilta-cel from CARTITUDE-1 and CARTITUDE-4 and published aggregated data for ide-cel from KarMMa-3. Cilta-cel patients who met inclusion criteria from KarMMa-3 were selected, and outcomes were compared against data for ide-cel using simulated IPD derived from aggregate-level data from KarMMa-3. Patient characteristics were adjusted by reweighting cilta-cel IPD to match the distribution of prognostic factors in KarMMa-3. Comparative efficacy was estimated for response outcomes using a weighted logistic regression analysis and for progression-free survival using a weighted Cox proportional hazards model. Results: Patients treated with cilta-cel were 1.2 times more likely to achieve overall response (relative response ratio [RR]: 1.18 [95% confidence interval: 1.03-1.34]; p = 0.04), 1.3 times more likely to achieve very good partial response or better (RR: 1.34 [1.15-1.57]; p = 0.003), and 1.9 times more likely to achieve complete response or better (RR: 1.91 [1.54-2.37]; p < 0.0001) versus ide-cel patients from KarMMa-3. Cilta-cel was associated with a significant 49% reduction in risk of disease progression or death versus ide-cel (hazard ratio: 0.51 [95% confidence interval: 0.31, 0.84]; p = 0.0078). Conclusion: For patients with triple-class exposed RRMM treated with 2-4 prior lines of treatment, cilta-cel was found to provide superior clinical benefit over ide-cel in terms of response and progression-free survival.