BMS Zenbexus Receives FDA Accelerated Approval for Second-Line Multiple Myeloma Treatment
FDA Accelerated Approval Marks First Commercialization for CELMoD Class
Bristol Myers Squibb (BMS) received accelerated approval from the U.S. FDA in August 2026 for Zenbexus (iberdomide) for the treatment of relapsed or refractory multiple myeloma after at least one prior therapy. Zenbexus is an oral cereblon E3 ligase modulator (CELMoD) that binds to the cereblon (CRBN) E3 ubiquitin ligase, inducing the degradation of the transcription factors IKZF1 and IKZF3. The approved regimen is a triple combination with Darzalex Faspro (daratumumab and hyaluronidase-fihj) from Johnson & Johnson (JNJ) and dexamethasone. A key aspect is the introduction of a more potent targeted protein degradation approach at the first relapse stage, compared to existing immunomodulatory agents.
EXCALIBER-RRMM Demonstrates Deep Tumor Reduction
The accelerated approval is based on the EXCALIBER-RRMM (NCT04975997) study, a randomized Phase 3 trial in patients who had received at least one prior therapy. The Zenbexus, Darzalex Faspro, and dexamethasone arm achieved a minimal residual disease (MRD) negativity rate of 41%, compared to 21% in the Darzalex Faspro, Velcade (bortezomib), and dexamethasone arm. MRD negativity indicates a deep response with undetectable levels of myeloma cells within the limits of detection; however, the patient's long-term survival benefit needs to be confirmed through the ongoing assessment of progression-free survival (PFS). Therefore, clinical validation is being conducted concurrently with commercial launch and transition to full approval.
Reshaping Standard of Care and Intensifying Competition
Zenbexus is designed to complement, rather than replace, the anti-CD38 antibody Darzalex, maintaining the combination regimen while targeting the proteasome inhibitor Velcade. The competitive landscape includes Revlimid (lenalidomide), Pomalyst (pomalidomide), Kyprolis (carfilzomib) from Amgen (AMGN), and Sarclisa (isatuximab) from Sanofi (SNY). In later-line therapy, it competes with BCMA-targeted therapies such as Carvykti (ciltacabtagene autoleucel) from JNJ, Abecma (idecabtagene vicleucel) from BMS, and Tecvayli (teclistamab) from JNJ, for patient sequencing. The global multiple myeloma treatment market was estimated at approximately $29.24 billion in 2025, making early entry into the treatment paradigm a significant revenue driver.
A Growth Asset to Offset Revlimid's Patent Cliff
Zenbexus is part of the pipeline acquired by BMS through its $74 billion acquisition of Celgene in 2019, and is priced at approximately $28,000 per month in the U.S. With Revlimid's 2025 revenue expected to be approximately $3 billion, a decrease of $2.8 billion from the previous year, the commercialization of CELMoD is directly linked to defending against the patent cliff. William Blair forecasts that Zenbexus sales will exceed $1 billion in 2031. The FDA accepted the NDA for the follow-on CELMoD, mezigdomide, in July 2026, with a target action date of May 13, 2027, indicating that BMS is focusing on building a sustained myeloma franchise rather than a single product.
Zenbexus's Phase 3 MRD negativity rate of 41% versus 21% and FDA accelerated approval represent a regulatory milestone that enables CELMoD to generate revenue from the second-line setting in the $29.24 billion global multiple myeloma market. In the short term, the $28,000 monthly price and projected sales exceeding $1 billion in 2031 will partially offset the patent cliff of Revlimid, which is expected to decline to approximately $3 billion in 2025. Clinically, it is designed to complement Darzalex while replacing Velcade, intensifying competition with Kyprolis, Sarclisa, and BCMA-targeted therapies such as Carvykti, Abecma, and Tecvayli in terms of treatment sequencing. The medium- to long-term value depends on the confirmation of PFS in the EXCALIBER-RRMM trial, the transition to full approval, and the execution of BMS's CELMoD franchise, including mezigdomide, which is expected to be reviewed by the FDA on May 13, 2027.
Source: BioPharma Dive (rss)