Immunomodulatory Effects of Cemsidomide with Dexamethasone from Phase 1 Trial Demonstrated Robust T-cell Activation, a Key Component of Cemsidomide’s Dual Mechanism of Action

Biomarker Data from First Two Patients in Phase 1b Trial of Cemsidomide with Elranatamab Reinforce Cemsidomide’s Ability to Drive T-cell Expansion and Activation, and Prevent T-cell Exhaustion When Combined with Immune-based Therapies

First Cemsidomide Dose Level (75 µg) in Phase 1b Trial with Elranatamab Declared Safe by Safety Data Review Committee; Advancing Trial to Dose Expansion and Escalation Cohorts with Data from All Cohorts Evaluated Expected in Mid-2027

WATERTOWN, Mass., Sept. 25, 2026 (GLOBE NEWSWIRE) -- C4 Therapeutics, Inc. (C4T) (NASDAQ:CCCC), a clinical-stage biopharmaceutical company dedicated to advancing targeted protein degradation (TPD) science, presented new biomarker data today from its Phase 1 clinical trial of cemsidomide in combination with dexamethasone in patients with relapsed/refractory multiple myeloma (RRMM) in a poster presentation at the 23rd IMS Annual Meeting. In addition, the poster included preliminary biomarker data from the first two patients in the ongoing Phase 1b trial of cemsidomide in combination with elranatamab (ELREXFIO®). These data further build upon the body of evidence supporting cemsidomide's immunomodulatory activity and potential as a combination partner.