[Jiwan Kim, Edaily Reporter] Biotech stocks moved in sharply different directions on Sept. 17 as investors reacted to corporate restructuring and drug development updates.

Orum Therapeutics plunged more than 33% in after-hours trading after Bristol Myers Squibb (BMS) discontinued development of the blood cancer candidate ORM-6151 and returned the rights to the company. In contrast, Oscotec rose 8.59% after forming a special committee to pursue the full acquisition of Genosco, while AriBio gained 5.59% on plans to invest 18 billion KRW in AriBioLab together with AriBio Holdings.

Orum Plummets After BMS Returns ORM-6151

BMS has discontinued development of ORM-6151, a blood cancer candidate licensed from Orum Therapeutics, and returned the rights to the Korean biotech company.

ORM-6151 was Orum Therapeutics’ only clinical-stage asset. BMS had been conducting a Phase 1 study in the United States, Europe, and Canada for acute myeloid leukemia and myelodysplastic syndromes, including monotherapy and combination treatment with azacitidine and venetoclax.

Following the news, Orum Therapeutics traded at 35,500 KRW at 6:02 p.m. in after-hours trading, down 33.52% from its regular-session close of 53,400 KRW.

The termination eliminates approximately $80 million in remaining development milestone payments, although Orum Therapeutics will retain the $100 million upfront payment received under the 2023 licensing agreement.

The termination also leaves Orum Therapeutics without a clinical-stage pipeline. The company plans to advance another DAC candidate, ORM-1153, into clinical development by the end of next year.

Orum Therapeutics had previously halted development of ORM-5029, a HER2-targeting DAC candidate, after serious adverse events—including one death—were reported in a Phase 1 study in 2024.

With both ORM-5029 and ORM-6151 discontinued, future clinical data from candidates such as ORM-1153 will be crucial in demonstrating the potential of the company’s DAC platform.

Oscotec Shares Rise on Genosco Acquisition Plan

Oscotec closed at KRW 37,300, up 8.59%, after announcing the formation of a special committee to pursue the acquisition of Genosco’s remaining shares.

Oscotec currently owns 59.31% of U.S.-based Genosco, which helped develop lazertinib, the original compound behind the FDA-approved lung cancer drug Lazcluze.

The committee will review potential conflicts of interest, select external valuation firms, and assess key issues related to the acquisition. Oscotec is also considering valuations from multiple outside institutions.

Following the valuation process, the company plans to negotiate with Genosco’s minority shareholders and finalize the transaction structure and financing plan. It may also bring in strategic or financial investors to alleviate financial pressure on existing shareholders.

AriBio Shares Rise on KRW 18 Billion Investment

AriBio and AriBio Holdings will invest KRW 15 billion and KRW 3 billion, respectively, in AriBioLab through a third-party share offering.

Following the transaction, AriBio will hold a 15.9% stake and become AriBioLab’s largest shareholder, while AriBio Holdings will own 14.1%. Their combined stake will reach 30%.

AriBio is conducting global Phase 3 trials of AR1001, an oral Alzheimer’s disease treatment candidate, while AriBioLab is developing vaccines and immunotherapies based on its proprietary immune-adjuvant platforms.

AriBioLab’s pipeline includes the Phase 2 shingles vaccine candidate CVI-VZV-001 and the mRNA-LNP-based immuno-oncology candidate CTRNA-001.

The companies have also begun jointly developing an Alzheimer’s vaccine, and the latest investment is expected to strengthen their collaboration across Alzheimer’s therapies, vaccines, and immuno-oncology.