By Sabrina Valle
NEW YORK, April 22 (Reuters) – Inhibrx Biosciences has drawn interest from drugmakers including Merck & Co, Germany’s Merck KGaA and Japan’s Ono Pharmaceutical for an experimental cancer treatment that could be valued at more than $8 billion, people familiar with the matter said.
The San Diego-based biotech is exploring the joint spin-off of the drug, INBRX-106, and a second experimental cancer treatment, which could have a combined value of more than $9 billion if clinical trials succeed, the people said.
Interest is concentrated on INBRX-106, which is being tested alone and in combination with Merck’s Keytruda. Inhibrx has said it believes its drug can boost the efficacy of New Jersey-based Merck’s more than $30-billion-a-year immunotherapy, the world’s top-selling prescription medicine.
Keytruda, which is approved to treat a wide variety of cancers, accounted for almost half of Merck’s global sales in 2025.
Talks are in early stages and any deal would likely be several months away, with valuation hinging on upcoming trial results, the people said, speaking on condition of anonymity because the matter is private.
Inhibrx and Merck declined to comment. German Merck and Ono did not respond to requests for comment.
The Inhibrx stock, which closed at $84 on Tuesday, surged as much as 85% to $155 on Wednesday after the Reuters report and a company update on the second drug, ozekibart.
The shares pared some of those gains but were still up more than 39% at $117.27 in afternoon trading, a move some traders said was fueled by short sellers rushing to cover positions.
DERISKING DATA
Stifel brokerage firm doubled its Inhibrx price target to $300 on Wednesday. It also forecast ozekibart sales eventually reaching more than $10 billion a year, following a company update on the drug.
It said it was encouraged by company commentary on the drug’s activity in colorectal cancer regardless of genetic mutations.
People close to the initial deal talks had earlier valued the therapy at about $1 billion.
Ozekibart, designed to promote cancer cell death, has shown positive results against Ewing sarcoma and colorectal cancer and received fast track and orphan drug designations from the U.S. Food and Drug Administration.
The company said it may meet with the FDA in the second half of the year to discuss accelerated approval for refractory Ewing sarcoma and as a fourth-line colon cancer treatment.
INBRX-106 could be worth $8 billion or more if trials confirm its potential to boost Keytruda’s already impressive efficacy. Ultimate valuation will depend on how well patients respond, the people said.
The drug is an antibody that boosts immune response by activating a receptor on T cells, a key component of the immune system.
Preliminary results from more than half of the 60 recruited patients in Phase 2/3 combination trials with Keytruda so far support the potential to improve patient overall response rates to 45%, from 30% with Keytruda alone, one of the people said.
The company is planning to disclose interim results next month, one of the people said.
“We think INBRX-106 is highly investable through targeting the narrow Keytruda-responder base to enhance this $32 billion drug’s cure-like efficacy,” Stifel biotech analyst Dara Azar said in a recent client note.
Clinical trials are being conducted in patients with advanced head and neck cancers, which have limited treatment options.
BUYER APPEAL
INBRX-106 would be of particular strategic interest to Merck, which is looking for new revenue sources as its blockbuster immunotherapy faces the loss of patent protections in 2028.
That strategic fit, however, does not give Merck an advantage as a potential buyer, the people said.
INBRX-106 could equally attract attention from other top-tier drugmakers looking to bolster their immuno-oncology offerings, the people said. Those include Eli Lilly, AstraZeneca, Pfizer and J&J, one of the people said.
The drug is unlikely to reach the market before Merck begins facing competition from less expensive biosimilar versions of Keytruda.
Inhibrx is considering a spinout structure similar to its 2024 deal with Sanofi, one of the people said. In that transaction, Sanofi acquired INBRX-101 for $30 per share in cash, plus a $5 contingent value right tied to regulatory milestones.
(Reporting by Sabrina Valle in New York; Editing by Echo Wang and Bill Berkrot)


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