Bristol Myers wins ‘milestone’ FDA approval of myeloma drug acquired from Celgene

Dive Brief:

The Food and Drug Administration granted an accelerated approval Thursday to Bristol Myers Squibb’s Zenbexus, a decision that could help the drugmaker sustain a multiple myeloma franchise in decline due to generic competition.
The approval is a “milestone” for medicines like Zenbexus, which are called “CELMoDs” and harness the body’s waste disposal system to trash diseased cells, wrote William Blair analyst Matt Phipps wrote in a note to clients. Bristol Myers has multiple CELMoDs in development, including a second myeloma treatment nearing approval. Inherited through an acquisition of Celgene, that portfolio is “underappreciated by investors,” wrote RBC Capital Markets analyst Trung Huynh.
The clearance makes Zenbexus available for second-line use alongside Johnson & Johnson’s Darzalex and the steroid dexamethasone. Huynh speculated that the Zenbexus combination might start “displacing” other second-line, Darzalex-based regimens, such as pairings with Bristol Myers’ Revlimid and Pomalyst or Amgen’s Kyprolis.

Dive Insight:

Bristol Myers won its latest approval based on Phase 3 data showing the Zenbexus combination was superior to a regimen involving Velcade at helping people become “minimal residual disease-negative,” meaning they had a very low number of malignant cells in the bone marrow following treatment.

The clearance also provided investors a glimpse of the magnitude of Zenbexus’ impact, with 41% of recipients achieving MRD-negative status compared with 21% of those who got Velcade. It’s not yet clear whether the drug helped extend survival.

The trial is also measuring Zenbexus’ potential to delay disease progression. Bristol Myers expects to report results in the next few months, and a positive finding could support a case for full approval. Bristol Myers is additionally testing Zenbexus in a “maintenance” study involving people who’ve received a bone marrow transplant. Success there is “seen as driver of broader physician engagement over time,” RBC’s Huynh wrote.

A substantial number of people with multiple myeloma could be eligible for treatment as a result of Thursday’s approval alone, Huynh added. Roughly 50% to 70% of those in the second-line setting have never been exposed to Darzalex, or have only been lightly treated with it, he wrote.

Zenbexus’ monthly price tag of $28,000 came in higher than Phipps was expecting, leading his team at William Blair to hike sales forecasts past $1 billion in 2031. Bristol Myers’ longtime multiple myeloma blockbuster Revlimid, by comparison, recorded sales of nearly $3 billion in 2025, while Pomalyst pulled in $2.7 billion. Revenue totals for both are shrinking, with sales for Revlimid alone plunging by $2.8 billion last year and expected to fall even more in 2026.

Bristol Myers is close to obtaining an approval for a second CELMoD drug in multiple myeloma. Called mezigdomide, the drug succeeded in late-stage testing earlier this year. An FDA decision is expected by May 13.