Lilly closes $6.3 billion purchase of Centessa and its sleep-wake drug pipeline

Eli Lilly and Company completed its acquisition of Centessa Pharmaceuticals plc on June 24, 2026, closing a transaction the two companies announced on March 31 of the same year ^[1][2]. The purchase adds a group of experimental orexin-2 receptor agonists that Centessa was studying in narcolepsy and other conditions marked by excessive daytime sleepiness ^[1][2].

Lilly agreed to pay $38.00 in cash for each Centessa share, plus one non-transferable contingent value right per share that can pay as much as $9.00 ^[1]. Lilly put the upfront equity value at approximately $6.3 billion and the maximum value of those milestone rights at about $1.5 billion, for total potential consideration of up to $47.00 per share ^[1]. The cash price was a premium of about 40.5% over the 30-day volume-weighted average trading price of Centessa's American Depositary Shares through March 30, 2026 ^[1]. Entities tied to Medicxi Ventures, Index Ventures and General Atlantic signed voting and support agreements covering roughly 24.1% of Centessa's ordinary shares ^[1].

How the extra payments are triggered

The contingent value rights pay nothing on their own. Each has a separate trigger, and each requires the FDA to clear either cleminorexton (previously known as ORX750) or a second candidate, ORX142 ^[1]:

• $2.00 per right if the FDA approves one of the drugs for narcolepsy type 2 within five years of closing.
• $5.00 per right if the FDA approves one of them for idiopathic hypersomnia within five years of closing.
• $2.00 per right for a first FDA approval in any indication before January 1, 2030 ^[1].

Both candidates remain investigational, and the announcement said "there can be no assurance that any payments will be made with respect to the CVR" ^[1].

What Centessa brings

Centessa's medicines are designed to act on orexin receptor 2, part of the brain circuitry that governs when people are awake and asleep ^[1]. Cleminorexton showed what the company described as a potential best-in-class profile in Phase 2a studies spanning narcolepsy type 1, narcolepsy type 2 and idiopathic hypersomnia ^[1]. The portfolio also holds clinical and preclinical-stage assets that Centessa suggested could reach other neurological, neurodegenerative and neuropsychiatric conditions ^[1].

Carole Ho, Lilly's executive vice president and president of Lilly Neuroscience, said when the deal closed that the orexin system governs "wakefulness, alertness, and the stability of sleep in ways that, when disrupted, can be profoundly disabling," adding that Lilly "intends to pursue that potential with urgency" ^[2]. At the announcement she called orexin receptor biology "one of the most compelling mechanistic opportunities in neuroscience" ^[1]. Centessa chief executive Mario Alberto Accardi described the portfolio as having the "depth and breadth that could help redefine what's possible in neuroscience" ^[1].

The purchase was structured as a scheme of arrangement under English law, which required a Centessa shareholder vote, sanction by the High Court of Justice of England and Wales, and other customary conditions including regulatory approvals ^[1].

Why it matters for patients

Nothing in the transaction changes a medicine anyone takes today. Lilly's approved products, including its diabetes and obesity drugs, were not part of the deal, and no label, price or supply changes were announced ^[1][2]. Neither Centessa candidate has been approved by the FDA ^[1].

For people living with narcolepsy type 2 or idiopathic hypersomnia, the immediate effect is ownership: a large company with late-stage development, regulatory and commercial capacity now controls the program ^[1][2]. The payment schedule also gives Lilly a concrete financial reason to reach approvals in those two diagnoses, since $7.00 of the $9.00 maximum per right is tied specifically to them ^[1].

Several things remain unanswered. Lilly has not reported when later-stage trials will start or finish, when it might file for FDA approval, what the drugs would cost if cleared, or when patients could get them ^[1][2]. The deal terms say nothing about which programs Lilly will advance first, including the narcolepsy type 1 work.

What happens next

Two dated deadlines now sit on the calendar. A first approval in any indication must come before January 1, 2030 to release $2.00 per right, and approvals in narcolepsy type 2 and idiopathic hypersomnia must arrive within five years of the June 24, 2026 closing, which falls in June 2031 ^[1][2]. How Centessa's team and pipeline will be folded into Lilly's neuroscience organization has not been disclosed ^[2].