US pharmaceutical giant Eli Lilly has entered into a definitive agreement to acquire London-based clinical-stage company Centessa Pharmaceuticals in a transaction valued at approximately $6.3 billion (€5.8 billion), targeting a pipeline of orexin receptor agonists designed to treat excessive daytime sleepiness and related neurological conditions.

According to Lilly Investors, the deal offers Centessa shareholders $38.00 (€35.15) per share in cash, plus one non-transferable contingent value right worth up to an additional $9.00 (€8.32) per share, tied to the achievement of three US FDA approval milestones, bringing total potential consideration to $47.00 (€43.47) per share. The cash consideration represents a premium of approximately 40.5% to Centessa's 30-day volume-weighted average trading price ended 30 March 2026.

Centessa's lead investigational candidate, cleminorexton, has demonstrated a potential best-in-class profile in Phase 2a clinical studies across narcolepsy type 1, narcolepsy type 2, and idiopathic hypersomnia. The company's broader OX2R agonist portfolio includes additional clinical and preclinical assets with potential utility across neurological, neurodegenerative, and neuropsychiatric conditions.

Carole Ho, executive vice president and president of Lilly Neuroscience, said: "Orexin receptor biology represents one of the most compelling mechanistic opportunities in neuroscience as a direct intervention on the master switch of the sleep-wake cycle. Centessa has assembled a portfolio with the breadth and depth to improve wakefulness across a broad array of indications."

Mario Alberto Accardi, chief executive of Centessa, said the combination would allow both organisations to accelerate advancement of the orexin portfolio across a broad range of neuroscience indications, ultimately benefiting patients who urgently require new therapeutic solutions.

Read the full announcement for complete details on the transaction terms and pipeline assets.