Anti-BCMA CAR T-cell therapy bb21217 with bb007 showed 69.4% response in relapsed multiple myeloma.

This Phase I study assessed the safety and preliminary efficacy of anti-B-cell maturation antigen (BCMA) CAR T-cell therapy bb21217 manufactured in the presence of the phosphoinositide 3-kinase inhibitor bb007. The intervention involved administering bb21217 to patients with relapsed or refractory multiple myeloma. No comparator group was reported for this early-phase investigation.

Primary and secondary outcomes included duration of response (DOR), objective response rate, expansion, and depth of response. The objective response rate was 69.4%. The median DOR was 23.8 months, with a 95% confidence interval of 16.8 to 34.8 months. An association was established between early memory phenotype and robust expansion and depth of response. Additionally, tumor burden and prior therapies were found to influence DOR.

Safety analysis noted three cases each of grade ≥3 cytokine release syndrome and grade ≥3 neurotoxicity. No new safety concerns were raised with bb21217 therapy. Discontinuations were not reported. The study design limits the ability to draw definitive conclusions regarding long-term survival or comparative effectiveness.

Key limitations include the small sample size typical of Phase I trials and the lack of a control group. The association between early memory phenotype and expansion was established through analysis of the drug product. Further research is needed to confirm these results in larger, randomized populations.