C4 Therapeutics' Cemsidomide Shows Immune Activation in Multiple…

Event summary

C4 Therapeutics presented biomarker data from Phase 1 trials of cemsidomide with dexamethasone and Phase 1b trials with elranatamab at the 23rd IMS Annual Meeting on September 25, 2026.
Phase 1 trial data showed robust T-cell activation and NK cell reprogramming in relapsed/refractory multiple myeloma patients.
Phase 1b trial data from two patients indicated cemsidomide drives T-cell expansion and prevents T-cell exhaustion when combined with elranatamab.
The 75 µg dose level of cemsidomide in combination with elranatamab was declared safe, advancing the trial to dose escalation and expansion cohorts.
Data from all cohorts in the Phase 1b trial are expected in mid-2027.

The big picture

C4 Therapeutics' data reinforces the potential of cemsidomide as a backbone therapy in multiple myeloma, addressing the critical challenge of T-cell exhaustion in immune-based therapies. The strategic focus on combination therapies aligns with the broader industry trend towards leveraging targeted protein degradation to enhance treatment efficacy. The next critical milestone will be the mid-2027 data release, which could position cemsidomide as a key player in the relapsed/refractory multiple myeloma landscape.

What we're watching

Clinical Efficacy: Whether the observed immune activation translates into meaningful clinical outcomes in the Phase 1b trial.
Dose Optimization: The pace at which C4 Therapeutics can identify the optimal dose of cemsidomide in combination with elranatamab.
Regulatory Pathway: How the mid-2027 data release will shape the regulatory strategy for cemsidomide.