Shares of Inhibrx Biosciences (NASDAQ:INBX) climbed more than 20% after a report said the company has attracted acquisition interest from several drugmakers, including Merck & Co (NYSE:MRK), Germany's Merck KGaA, and Ono Pharmaceutical. The surge followed publication of details indicating multiple parties are considering offers tied to the biotech's experimental oncology assets.
According to people familiar with the matter, the San Diego-based company is weighing a transaction structure that could involve a joint spin-off of its lead candidate, INBRX-106, alongside a second investigational cancer drug. Those two programs together could hold a combined valuation in excess of $9 billion if they clear clinical milestones and prove successful in trials.
Market attention is concentrated on INBRX-106. The drug is undergoing studies both on its own and in combination with Merck's Keytruda. Sources cited in the report estimated the INBRX-106 program alone could be worth more than $8 billion, though they emphasized that any ultimate price would be determined by how patients respond in ongoing and future clinical trials.
Inhibrx has stated its belief that the drug has the potential to enhance the performance of Keytruda. The report noted Keytruda accounted for almost half of Merck's global sales in 2025 and generates more than $30 billion in annual revenue for the company.
People familiar with discussions said talks remain at an early stage and that any deal would likely be several months away. The timeline and valuation are expected to hinge on forthcoming trial results, according to those same sources. Inhibrx declined to comment, while Merck, Germany's Merck and Ono did not immediately respond to requests for comment.
Summary
Inhibrx stock jumped after reports that major pharmaceutical firms have expressed takeover interest in its experimental cancer therapies, with the company exploring a joint spin-off that could have a combined value exceeding $9 billion if clinical trials succeed. INBRX-106 is the primary focus of interest and is being tested alone and with Merck's Keytruda; its standalone value was estimated at more than $8 billion pending trial outcomes.
Key points
- Inhibrx shares rose over 20% on reports of takeover interest from Merck & Co, Merck KGaA, and Ono Pharmaceutical.
- The company is exploring a joint spin-off of INBRX-106 and a second experimental cancer treatment with a potential combined value above $9 billion if trials succeed.
- Interest is concentrated on INBRX-106, which is being evaluated alone and in combination with Merck's Keytruda; that program alone could be valued at more than $8 billion depending on patient responses in trials.
Risks and uncertainties
- Talks are in the early stages and any transaction would likely be several months away - uncertainty affects deal timing and near-term market reaction.
- Valuation is contingent on clinical trial results; the ultimate price depends on how patients respond, introducing clinical development risk.
- Companies involved did not provide comment when contacted, leaving public information limited and subject to change as discussions evolve.