Eli Lilly will acquire Centessa Pharmaceuticals in an all-cash transaction valued at $6.3 billion, targeting the company's sleep disorder treatment programs to complement its metabolic therapy lineup. The deal underscores Lilly's commitment to expanding its portfolio beyond diabetes and obesity therapeutics.

Centessa's stock surged 44%, trading as high as $40.26 and closing around $39.90, while options volume soared to 3,467 calls and 2,687 puts—more than 11 times the typical intraday activity. Analysts at Needham and B. Riley downgraded Centessa to hold or neutral, and Piper Sandler trimmed its rating to neutral, signaling a tempered outlook despite the rally.

The acquisition aims to enhance Eli Lilly's growth outlook by adding novel sleep disorder assets that address unmet patient needs and diversify revenue streams. By integrating Centessa's pipeline, Lilly plans to leverage its established commercial capabilities to accelerate development and market access.