Eli Lilly agreed to acquire Centessa Pharmaceuticals for about $6.3 billion upfront, aiming to expand its neuroscience pipeline with orexin receptor 2 (OX2R) agonists. The deal follows positive phase 2a data for Centessa’s lead program, cleminorexton (ORX-750), across narcolepsy type 1, narcolepsy type 2, and idiopathic hypersomnia. Lilly will pay $38 per Centessa share and also offers contingent value rights that could add roughly $1.5 billion tied to FDA approvals for cleminorexton and ORX142. Centessa also has earlier-stage OX2R programs (ORX142 in clinical development and ORX489 in preclinical research), expanding the potential addressable market beyond narcolepsy. The purchase intensifies competition in the sleep-disorders drug class, where multiple companies are pursuing orexin or sleep-wake–pathway interventions. The transaction highlights Lilly’s strategy to redeploy cash generated in other therapeutic areas into high-innovation, multi-asset CNS franchises. For biotech, the Centessa acquisition is another example of how clinical-stage programs with clear mechanistic differentiation can trigger premium buyouts—especially when they target large, underserved markets such as excessive daytime sleepiness and wakefulness disorders.