C4 Therapeutics doses first patient in Phase 1b trial combining cemsidomide with elranatamab for multiple myeloma

C4 Therapeutics has dosed the first patient in a Phase 1b trial testing cemsidomide, an oral IKZF1/3 degrader, combined with elranatamab, an FDA-approved bispecific antibody, for relapsed/refractory multiple myeloma. This trial aims to find the optimal dose and assess safety, tolerability, and preliminary efficacy in up to 54 patients. The combination targets both direct anti-myeloma effects and immune system activation, potentially improving treatment outcomes. Results are expected by mid-2027, supporting cemsidomide’s use in earlier therapy lines alongside ongoing Phase 2 studies.