Eli Lilly and Co. plans to buy Centessa Pharmaceuticals plc for $6.3 billion in up-front cash and another potential $1.5 billion through contingent value rights, gaining access to a pipeline of orexin receptor 2 agonists for sleep disorders. The Indianapolis-based pharma is re-entering a field that has multibillion-dollar potential and one that could emulate the success seen with its obesity program. Centessa, of Boston and London, has a lead candidate, cleminorexton (formerly ORX-750), with positive phase IIa data in narcolepsy types 1 and 2 and idiopathic hypersomnia.

Centessa Pharmaceuticals plc’s unremarkable third-quarter 2025 earnings report was greatly overshadowed by an early readout from its orexin receptor 2 (OX2R) agonist program in narcolepsy, particularly promising phase IIa data demonstrating ORX-750’s efficacy across a group of sleep disorders, though investors seek further data to differentiate Centessa’s program from potential competitors such as Takeda Pharmaceutical Co. Ltd.’s oveporexton and Alkermes plc’s alixorexton.

Takeda Pharmaceutical Co. Ltd.’s dual phase III victories in narcolepsy type 1 (NT1) with oral orexin receptor 2 (OX2R)-selective agonist oveporexton (also known as TAK-861) had Wall Street mulling what the outcome might mean for others trying the mechanism of action, and questions linger about side effects on eyesight.

Takeda Pharmaceutical Co. Ltd.’s dual phase III victories in narcolepsy type 1 (NT1) with oral orexin receptor 2 (OX2R)-selective agonist oveporexton (also known as TAK-861) had Wall Street mulling what the outcome might mean for others trying the mechanism of action, and questions linger about side effects on eyesight.