C4 Therapeutics (CCCC) investor relations material

Lead program and clinical development

• Lead asset cemsidomide is a cereblon modulating degrader targeting IKZF1/3, advancing in multiple myeloma across late and earlier lines, with ongoing phase II (MOMENTUM) and phase I-B combo studies.

• Recent data updates show deepening responses, robust efficacy at multiple doses, and excellent tolerability, supporting its potential as a backbone therapy.

• MRD negativity is now an FDA-accepted surrogate endpoint, streamlining future development and regulatory pathways.

• T-cell engagers are moving into earlier lines, and cemsidomide is being studied in combination with elranatamab to enhance depth and durability of remission.

• The MOMENTUM phase II trial is on track, with enrollment completion expected by end of Q1, targeting a 40% response rate over a 20% background.

Efficacy, safety, and market opportunity

• At 100 micrograms, cemsidomide achieved a 53% ORR and durable responses, with a median DOR of 7.9 months and no discontinuations due to safety.

• Neutropenia is manageable, mostly occurring in the first two cycles, and physicians are experienced in handling it.

• The late-line multiple myeloma market is expected to grow as more effective therapies move earlier, with an estimated $1 billion opportunity.

• An all-oral regimen is seen as advantageous for community-based patients.

• Response rates were consistent across prior lines of therapy and BCMA exposure.

Combination strategies and future plans

• Ongoing phase I-B study combines cemsidomide with elranatamab, focusing on safety and establishing a tolerable dose, with mid-2027 efficacy data expected.

• Additional phase I-B studies will evaluate combinations with daratumumab and carfilzomib, aiming to establish broad combinability.

• Interest in exploring combinations with CAR-T and trispecific TCEs, with some studies likely to be investigator-sponsored.

• Future updates will focus on safety results and dose optimization, with MRD negativity and CR rates as key efficacy benchmarks.

• Decision points on commercialization and potential partnerships are expected after key readouts, with a base case of independent execution.