Bristol Myers Squibb Drops Orum’s ORM-6151 After Phase 1 Review, Cutting Off Up To $80 Million In Milestones

Bristol Myers Squibb has ended development of ORM-6151, the degrader-antibody conjugate it bought from Orum Therapeutics for $100 million in 2023, after reviewing phase 1 clinical data. Orum disclosed the decision in a financial filing.

The stop is notable both for what it says about this specific program and for what it suggests about the current bar for degrader-antibody conjugates. Bristol Myers had advanced the asset into the clinic, but the company has now chosen not to carry it forward, cutting off Orum’s chance to receive up to $80 million in clinical development milestones.

The Program Bristol Myers Walked Away From

ORM-6151, which Bristol Myers called BMS-986497, was designed to deliver a GSPT1 degrader to cells expressing CD33. The rationale was straightforward: degrading the housekeeping protein GSPT1 can lead to cell death, and acute myeloid leukemia and myelodysplastic syndrome cells often express CD33, creating a potential route to selective targeting in those blood cancers.

Bristol Myers began testing that concept in 2024 in a phase 1 trial that evaluated ORM-6151 as a monotherapy and in double and triple combinations with azacitidine and venetoclax. According to the federal trials register cited by Fierce Biotech, the study had been due to wrap up in February 2027. Instead, the program has been halted early after the company’s look at clinical data.

The source does not describe the specific efficacy or safety findings behind the decision, so the clearest interpretation is strategic rather than mechanistic: the data were not strong enough for Bristol Myers to justify continued investment.

What It Means For Orum And The DAC Field

For Orum, the financial impact is immediate. Beyond losing a large pharma partner on this asset, the company no longer has access to the up to $80 million tied to future development milestones.

For the broader field, the decision adds another setback for degrader-antibody conjugates. Fierce Biotech noted that AbbVie started a phase 1 trial in 2023 of ABBV-787, another CD33-directed DAC, this one with a BET degrader payload, but terminated that study last year for strategic considerations. Two separate discontinuations do not settle the fate of the modality, but they do suggest that translating DAC theory into a viable clinical product is proving harder than early dealmaking implied.

The repeated focus on CD33 also echoes an older playbook from antibody-drug conjugates. Orum based the antibody in ORM-6151 on the targeting molecule in Mylotarg, gemtuzumab, with modifications intended to support manufacturing and improve safety. That may have reduced some target-risk uncertainty, but it was not enough to keep the program alive once human evidence came into view.

Bristol Myers’ decision also fits a broader pattern under CEO Christopher Boerner, Ph.D., who took over in 2023. Fierce Biotech described ORM-6151 as one of many projects the company has jettisoned since then, including internal and partnered programs associated with the prior leadership period. In that sense, the termination is not just a read on one oncology asset. It is another example of large drugmakers becoming less patient with external innovation bets when early clinical data do not clearly support the next tranche of spending.