Third Opinion Trial Synopsis
This study is about testing a new treatment called bb2121 for people with a type of cancer called multiple myeloma. They will test it on three different groups of people who have either had previous treatments or are newly diagnosed. Around 235 people will be enrolled in the study. They will test to see if the treatment is effective and safe for the different groups.

Trial Summary
This study is a multi-cohort, open-label, multicenter Phase 2 study to evaluate the efficacy and safety of bb2121 in participants with relapsed and refractory multiple myeloma (RRMM) (Cohort 1), in participants with RRMM who receive bridging therapy with talquetamab (Cohort 1b), in participants with multiple myeloma (MM) having progressed within 18 months of initial treatment with autologous stem cell transplantation (ASCT) (Cohort 2a) and without ASCT (Cohort 2b) or, in participants with inadequate response post ASCT during initial treatment (Cohort 2c) and the efficacy and safety of bb2121 used in combination with lenalidomide maintenance in participants with suboptimal response post ASCT (Cohort 3). Approximately 264 participants will be enrolled into one of three cohorts. Cohort 1 (including cohort 1b) will enroll approximately 126 RRMM subjects with ≥ 3 prior anti-myeloma treatment regimens. Cohort 2a will enroll approximately 39 MM subjects, with 1 prior anti-myeloma therapy including ASCT and with early relapse. Cohort 2b will enroll approximately 39 MM subjects with 1 prior anti-myeloma therapy not including ASCT and with early relapse. Cohort 2c will enroll approximately 30 MM subjects with inadequate response to ASCT during their initial anti-myeloma therapy. The cohorts will start in parallel and independently. Cohort 3 will enroll approximately 30 newly diagnosed multiple myeloma (NDMM) participants with suboptimal response to ASCT.