[Edaily Reporter NA EUN-KYUNG ] #Orum Therapeutics, Inc. has halted clinical development of ORM-6151, a candidate drug for acute myeloid leukemia that it sold to Bristol-Myers Squibb (BMS). While the company is not required to return the $100 million (approximately 130 billion won at the exchange rate at the time) in upfront payments it had already received, it will not be able to receive the additional milestone payments of up to $80 million (approximately 111 billion won at the current exchange rate) that were scheduled to be paid.

Orum Therapeutics, Inc. announced on the 17th that BMS decided to halt development after reviewing clinical data for ORM-6151, which BMS had been developing under the new name BMS-986497. Consequently, the asset transfer agreement signed by the two companies in 2023 has been terminated, and BMS’s obligation to pay additional milestone payments has been eliminated.

BMS had been conducting Phase 1 clinical trials of ORM-6151 in the U.S., Europe, and Canada in patients with relapsed or refractory acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). The trials tested not only ORM-6151 as a monotherapy but also in dual and triple combination regimens with azacitidine and venetoclax.

The partnership between Orum Therapeutics, Inc. and BMS dates back to October 2023. At that time, Orum Therapeutics, Inc. sold ORM-6151 to BMS for a total of $180 million (approximately 234 billion won at the time). The deal featured exceptional terms, with Orum Therapeutics, Inc. receiving an upfront payment of $100 million—equivalent to 55.6% of the total contract value. Although ORM-6151 was still in the early stages of clinical development, the fact that the upfront payment exceeded half the total deal value drew attention as an unprecedented transaction in the domestic biotech industry.

ORM-6151 is an antibody-drug conjugate (DAC) that combines an antibody targeting CD33 on the surface of cancer cells with a GSPT1 protease. While conventional antibody-drug conjugates (ADCs) deliver cytotoxic drugs to cancer cells, DACs deliver drugs that eliminate proteins essential for cancer cell survival.

However, following the deal, safety concerns arose regarding ORM-5029—another DAC candidate that Orum Therapeutics, Inc. had been developing in-house—leading to worries that these issues might spill over to ORM-6151 as well. Unlike ORM-6151, ORM-5029 targeted HER2 and was being developed as a treatment for HER2-positive metastatic breast cancer and other HER2-expressing solid tumors; however, in 2024, one patient died of liver failure during a Phase 1 clinical trial, and clinical development was ultimately discontinued in April 2025.

Although the two candidate compounds target different cancer cells and antibodies, they use payloads with the same mechanism of action. Consequently, market attention focused on whether the toxicity observed with ORM-5029 was an issue specific to that individual candidate or a broader problem with GSPT1 inhibitors or the DAC platform as a whole.

Subsequently, BMS tripled the enrollment for the ORM-6151 clinical trial from 35 to 105 patients and added a combination arm with azacitidine and venetoclax in addition to monotherapy, which seemed to somewhat alleviate these concerns. While expanding a clinical trial does not in itself guarantee a candidate’s success, it was interpreted as a sign that BMS remains committed to its development. Since the start of this year, the company has also expanded the clinical trial regions and institutions to include Europe and Canada.

However, when BMS ultimately decided to halt development based on clinical data, Orum Therapeutics, Inc. lost the opportunity to receive the remaining $80 million in milestone payments. The $100 million upfront payment already received, however, will not be returned. Since BMS did not disclose specific clinical data or the reasons for the termination, it remains unconfirmed whether this decision was due to toxicity issues similar to those observed with ORM-5029.

Orum Therapeutics, Inc. stated, “We plan to focus our R&D capabilities on our own pipeline utilizing the DAC platform.”