French healthcare company Sanofi has agreed to buy U.S. biotech firm Inhibrx in a deal valued at up to $2.2 billion, bolstering its drug development portfolio with an experimental treatment for a rare genetic disease.
The companies said the deal will give Sanofi access to Inhibrx’s INBRX-101, currently in the second of three phases of clinical trials, while its other experimental drugs will be spun off into a separate company, with Sanofi retaining an 8% stake.
INBRX-101 is designed to treat Alpha-1 Antitrypsin Deficiency (AATD), an inherited rare disease that causes progressive deterioration of the lung tissue.
Sanofi, which makes most of its revenues from anti-inflammation treatments, last year abandoned 2025 earnings targets to boost the company’s research and development (R&D).
“The addition of INBRX-101 as a high potential asset to our rare disease portfolio reinforces our strategy to commit to differentiated and potential best-in-class products,” said Houman Ashrafian, Sanofi’s head of R&D.
U.S.-listed shares of Inhibrx rose 6.8% to $35.60 in premarket trading on the deal that will give shareholders $30 per share in cash, which represents an equity value of $1.7 billion, as well as 0.25 shares in the spun off company.
Inhibrx shareholders will also receive a “contingent value right” equal to $5, conditioned on the achievement of a regulatory milestone.
The spun-off company will operate under the Inhibrx name and will be led by Inhibrx chief Mark Lappe as CEO.
Sanofi will assume and retire Inhibrx’s outstanding third-party debts, and fund the spun-off company with $200 million in cash.
The global pharmaceuticals sector has seen a wave of takeover deals in recent months.
Last October, Bristol-Myers Squibb said it will acquire cancer drugmaker Mirati Therapeutics for up to $5.8 billion, while in March Sanofi bought Provention Bio for $2.9 billion.