Multiple myeloma is a malignant plasma cell disorder characterized by osteolytic lesions, increased susceptibility to infections, hypercalcemia, and renal failure. Talquetamab is a humanized immunoglobulin G4 proline, alanine, alanine (IgG4PAA) bispecific antibody designed to target G protein-coupled receptor family C group 5-member D (GPRC5D) and the CD3 molecule found on T lymphocytes (T cell). This study consists 3 periods: screening phase (up to 28 days), treatment phase (start of study drug administration and continues until the completion of the end of treatment [EOT (30 days (+ 7 days)] visit); and a post-treatment follow-up phase (until the end of study unless the participant has died, is lost to follow up or has withdrawn consent). Total duration of study is up to 2 years (after the last participant receives their first dose). Safety, pharmacokinetics (PK), laboratory tests, and questionnaire will be assessed at specified time points during this study. Participants safety and study conduct will be monitored throughout the study. The corresponding study (NCT03399799) is the Phase 1 part of the study and TALMMY1001- Part 3 is the Phase 2 part of the study.
The purpose of this study is to evaluate the efficacy of talquetamab in participants with relapsed or refractory multiple myeloma at the recommended Phase 2 dose(s) (RP2Ds) (Part 3).