As reported on drugs.com, Bristol Myers Squibb (BMS) has announced encouraging interim results from the Phase 3 portion of the SUCCESSOR-2 clinical trial evaluating oral mezigdomide in patients with relapsed or refractory multiple myeloma (RRMM). The study met its primary endpoint, demonstrating a statistically significant and clinically meaningful improvement in progression-free survival when mezigdomide was added to carfilzomib and dexamethasone, compared with carfilzomib and dexamethasone alone.
The findings represent a key milestone for mezigdomide, marking its first positive Phase 3 trial and the second successful Phase 3 study within BMS’s cereblon E3 ligase modulator (CELMoD) development program. Patients enrolled in the trial will continue to be followed for long-term survival outcomes and safety.
Addressing Persistent Unmet Needs in Multiple Myeloma
Multiple myeloma remains an incurable hematologic malignancy, and despite substantial therapeutic progress, most patients ultimately experience disease relapse or treatment resistance. The population enrolled in SUCCESSOR-2 reflects this challenge, consisting of patients with RRMM who have previously received established therapies, including anti-CD38 antibodies and lenalidomide.
According to investigators, the results highlight the potential role of MeziKd—an all-oral regimen combining mezigdomide, carfilzomib, and dexamethasone—in extending disease control in earlier relapse settings. Experts involved in the study emphasized that durable responses and convenient oral options remain high priorities for patients whose disease has become difficult to manage with existing treatments.
Trial Design and Key Endpoints
SUCCESSOR-2 (ClinicalTrials.gov identifier: NCT05552976) is a seamless Phase 2/3, multicenter, randomized, open-label study comparing the efficacy and safety of MeziKd versus carfilzomib plus dexamethasone (Kd) alone in RRMM. The primary endpoint for the Phase 3 portion is progression-free survival.
Secondary objectives include overall survival, overall response rate, duration of response, time to disease progression, time to next therapy, minimal residual disease negativity, and patient-reported health-related quality of life. Safety outcomes observed to date align with the established profiles of mezigdomide and the combination regimen, with no unexpected findings reported.
Mezigdomide and the CELMoD Platform
Mezigdomide is part of BMS’s next-generation CELMoD class, designed to enhance both direct tumor cell killing and immune activation beyond what has been achieved with earlier immunomodulatory drugs (IMiDs). CELMoD agents leverage targeted protein degradation, a therapeutic strategy that directs the cell’s own machinery to selectively eliminate disease-driving proteins.
BMS has played a central role in advancing protein degrader therapies in multiple myeloma, building on the clinical success of IMiDs that have become foundational to current standards of care. The company is expanding this approach through a broader targeted protein degradation portfolio that includes CELMoDs, ligand-directed degraders, and degrader antibody conjugates, with applications extending beyond hematologic malignancies.
Next Steps
BMS plans to present detailed data from SUCCESSOR-2 at an upcoming scientific meeting and will engage with global health authorities to discuss the regulatory implications of the findings. If confirmed with longer follow-up, the results may support a new oral treatment option for patients with relapsed or refractory multiple myeloma who have limited therapeutic alternatives.
