Cemsidomide Shows Immune Activation In C4 Therapeutics’ Myeloma Study

(RTTNews) – C4 Therapeutics Inc. (CCCC), a clinical-stage biopharmaceutical company focused on targeted protein degradation, presented new biomarker data from its Phase 1 trial of cemsidomide with dexamethasone and its Phase 1b trial of cemsidomide with elranatamab (ELREXFIO) in patients with relapsed/refractory multiple myeloma at the 23rd International Myeloma Society Annual Meeting.

In the Phase 1 trial, data from 62 heavily pre-treated patients showed coordinated activation of T cells, including CD8+ T cells, along with functional changes in natural killer cells.

Enhanced immune cell activity was observed at the highest cemsidomide doses evaluated, 75 µg and 100 µg.

Biomarker findings from the first two patients in the Phase 1b trial showed that cemsidomide promoted expansion and activation of CD8+ effector memory T cells, as measured by increased HLA-DR expression.

The initial data also indicated reduced markers associated with T-cell exhaustion, including PD-1, TIM-3 and LAG3, when cemsidomide was combined with elranatamab.

The findings provide early biomarker evidence supporting the potential use of cemsidomide as a combination partner for immune-based therapies in multiple myeloma.

Elranatamab is a BCMA-directed T-cell engager approved for the treatment of certain patients with relapsed or refractory multiple myeloma.

Following review of safety data from the first six patients in the Phase 1b study, the safety data review committee declared the 75 µg cemsidomide dose level in combination with elranatamab safe.

The Phase 1b trial is now advancing to a dose-escalation safety cohort evaluating 100 µg of cemsidomide and an expansion cohort evaluating the 75 µg dose.

The study is designed to assess safety, tolerability and preliminary efficacy of the combination.

Cemsidomide is an investigational oral cereblon-modulating protein degrader targeting IKZF1 and IKZF3, transcription factors involved in multiple myeloma biology.

C4 Therapeutics is evaluating the candidate as a potential combination therapy to enhance immune responses against myeloma cells.

Upcoming Milestones

C4 Therapeutics expects to evaluate data from all cohorts in the Phase 1b cemsidomide and elranatamab trial in mid-2027.

The company will continue advancing cemsidomide through clinical development in multiple myeloma, including dose escalation and expansion cohorts designed to further assess its safety, biomarker effects and potential anti-myeloma activity.

CCCC has traded between $1.69 and $5.17 over the past year. The stock is currently trading at $2.94, down 2.48%.