Eli Lilly agreed to acquire Centessa Pharmaceuticals in a deal valued at about $6.3 billion upfront, with additional contingent value rights that could add $1.5 billion tied to approvals in narcolepsy-related indications. The acquisition gives Lilly a late-stage portfolio centered on orexin receptor 2 (OXR2) agonism, led by cleminorexton (ORX750). Centessa’s mid-stage program includes Phase 2a data in narcolepsy type 1, narcolepsy type 2, and idiopathic hypersomnia, which Centessa described as dose-dependent and potentially best-in-class. Lilly positioned the deal as a way to expand its neuroscience franchise beyond weight management-related revenue into a sleep-wake market it described as multi-billion-dollar. Investor attention is likely to focus on whether cleminorexton can outperform or differentiate from other OXR2 approaches already in development, and on execution of pivotal trial timelines after the transaction closes. For Centessa shareholders, the price and CVR structure—tied to specific regulatory outcomes—creates a direct pathway from development milestones to economics. The transaction also highlights continued pharma willingness to spend from metabolic cash flows to build exposure in adjacent CNS categories with clear differentiated mechanisms.