C4 Therapeutics (CCCC) investor relations material

Clinical trial updates and data insights

• Phase II MOMENTUM study of cemsidomide showed a 53% response rate at the recommended 100 mcg dose in late-line patients, with robust safety and low discontinuation due to adverse events.

• Updated EHA presentation will provide longer follow-up and more granular safety and response data, especially for the 100 mcg cohort, but no new patient cohorts or changes in overall response rate.

• Safety profile highlighted low rates of Grade 4 neutropenia and dose reductions, with most adverse events occurring early and resolving, supporting class-leading tolerability.

• MOMENTUM study enrollment is on track to meet the goal by Q1 2027, with global site expansion and regulatory intent for potential accelerated approval.

• Phase I combination study with elranatamab is open and recruiting, with initial safety data expected by 2027 and a focus on establishing combinability and early CRs.

Competitive landscape and differentiation

• Cemsidomide is positioned as a potent degrader with efficacy comparable to MEZI and a safety profile similar to iberdomide, aiming for late-line and combination settings.

• Differentiation strategy focuses on late-line use and BiTE combinations, rather than replacing existing regimens in earlier lines.

• Ongoing and planned studies will establish cemsidomide as a preferred combination partner, with minimal dose-finding needed due to predictable dosing.

• Market opportunity in the fourth-line-plus setting is estimated at $1.5 billion, expected to grow as patients live longer post-CAR-T and BiTE therapies.

Industry developments and forward-looking statements

• Positive phase III data for MEZI in combination regimens is seen as validating for the class, with attention on dose intensity, safety, and supportive care in upcoming ASCO presentations.

• SUCCESSOR-1 trial results, comparing MEZI to pomalidomide, are anticipated to inform future pivotal trial designs and de-risk development strategies.

• Additional combination studies with PI and CD38-based triplets will start in the first half of next year, aiming to quickly identify optimal combination doses.

• Key external data sets being monitored include iberdomide in front-line quad regimens and golcadomide in NHL, reflecting broader opportunities for next-gen degraders.