Eli Lilly announced on Mar. 31 the acquisition of Centessa Pharmaceuticals for $6.3 billion, aiming to broaden its portfolio in sleep disorder treatments and enter direct competition with other major pharmaceutical companies.
The deal is structured at $38 per share with an additional contingent value right offering stockholders up to $9 more per share if certain milestones are achieved, such as obtaining one of two Food and Drug Administration approvals within a specified timeframe. This could potentially increase the total buyout value by another $1.5 billion. Both companies' boards have approved the agreement, which is expected to close in the third quarter of 2026.
At the center of this transaction is Centessa’s lead drug candidate, cleminorexton, an oral orexin receptor 2 agonist currently being tested for narcolepsy type 1, narcolepsy type 2, and idiopathic hypersomnia. Orexin plays a key role in regulating the sleep-wake cycle and promoting wakefulness; drugs targeting this pathway may help address excessive daytime sleepiness as well as improve attention and cognition.
Centessa released Phase 1 data in April 2025 showing that a five-milligram dose of cleminorexton delayed sleep by an average of nearly 38 minutes compared to about 15 minutes for placebo recipients—a statistically significant effect according to the company at that time. Analysts from Leerink wrote on April 7, "This readout reinforces ORX750 as a potentially best-in-class OX2R agonist relative to competitors." BMO Capital Markets analysts also described Centessa’s orexin receptor agonist as having “best-in-class” potential for narcolepsy.
With this acquisition, Lilly will be positioned against Takeda, whose late-stage oveporexton—also an OX2R agonist—has shown positive results in two Phase III studies and has been submitted for FDA approval with a decision expected later this year. Alkermes is another competitor developing alixorexton for narcolepsy type 2 following successful Phase II results presented last November.
In addition to cleminorexton, Lilly will acquire Centessa’s broader pipeline of OX2R agonists including preclinical assets aimed at treating neurological, neurodegenerative, and neuropsychiatric conditions.
