Cemsidomide (CFT7455) in Combination With ELREXFIO (Elranatamab)

September 25, 2026: C4 Therapeutics (NASDAQ: CCCC) reported IMS Annual Meeting biomarker data and a trial update for cemsidomide in relapsed/refractory multiple myeloma.

Cemsidomide + dexamethasone (Phase 1): In 62 heavily pre-treated RRMM patients across once-daily dose levels, cemsidomide showed coordinated T-cell activation, including CD8+ T cells, and functional reprogramming of NK cells. Enhanced immune cell function was observed at the highest tested doses (75 µg and 100 µg), which the company said also achieved compelling overall response rates in the Phase 1 trial.

Cemsidomide + elranatamab (Phase 1b): Preliminary biomarker data from the first two patients showed expansion and activation of CD8+ effector memory T cells, with elevated HLA-DR, and reduced markers of T-cell exhaustion measured by PD-1, TIM-3, and LAG3 expression. After the first safety cohort of six patients, the safety review committee declared the 75 µg cemsidomide dose level with elranatamab safe. The study is moving into a 100 µg dose-escalation safety cohort and a 75 µg expansion cohort. Data from all evaluated Phase 1b cohorts are expected in mid-2027.