Results
Overall, 106 patients with RRMM treated with a median of 4 prior lines were included; 25.5% had high‐risk cytogenetics, 63.2% were refractory to proteasome inhibitors and immunomodulatory agents, 26.4% were previously exposed to daratumumab, and 84.0% were refractory to their last treatment line. There were no major changes in the safety or pharmacokinetic profile of isatuximab with the addition of cemiplimab. As assessed by investigators, four patients (11.8%) in the Isa arm, nine patients (25.0%) in the Isa + CemiQ2W arm, and eight patients (22.2%) in the Isa + CemiQ4W arm were responders. Though response rates were numerically higher in cemiplimab‐containing arms, differences were not statistically significant and did not translate to improved progression‐free or overall survival after a median follow‐up of 9.99 months.