Neurocrine Biosciences agreed to acquire Soleno Therapeutics for $2.9 billion, adding Vykat XR (diazoxide choline) to its rare-disease portfolio and boosting its Prader-Willi syndrome exposure. The cash offer values Soleno at $53 per share, a 34% premium to its prior close. Vykat XR was approved in March 2025 for treating hyperphagia in Prader-Willi patients and generated about $190 million in 2025 revenue, according to deal disclosures. Analysts have flagged ongoing questions around growth trajectory and safety, but the acquisition also gives Neurocrine a commercially validated therapy with little near-term competition. For sector dealmaking, the transaction reinforces how profitable niche medicines continue to attract large pharma and mid-cap acquirers amid product pipeline uncertainty.