FDA Approves BMS's Zenbexus, First CELMoD Therapy for Multiple Myeloma

The Food and Drug Administration on August 13 granted accelerated approval to Bristol Myers Squibb's iberdomide, sold under the brand name Zenbexus, in combination with Johnson & Johnson's Darzalex and dexamethasone for adults with multiple myeloma who have received at least one prior line of therapy, STAT and Fierce Pharma reported. It is the first approved therapy in the cereblon E3 ligase modulation (CELMoD) class — a historic milestone for targeted protein degradation — and the first new drug cleared by U.S. regulators using minimal residual disease (MRD) as the basis of approval.

A New Surrogate Endpoint

The approval rests on the phase 3 EXCALIBER-RRMM trial, which showed an MRD-negative complete response rate of 41 percent with the iberdomide-led combination versus 21 percent for the standard regimen of Darzalex, Velcade and dexamethasone, at a median follow-up of 16 months. Progression-free survival, the trial's other primary endpoint, is still being evaluated, and BMS must provide confirmatory evidence under the accelerated pathway. William Blair analysts projected Zenbexus U.S. sales could surpass $1 billion in early 2031, and BMS's second CELMoD agent, mezigdomide, is under FDA review with a decision date of May 13, 2027. "Zenbexus marks the arrival of a new treatment class," BMS chief medical officer Cristian Massacesi said.