Angelini Pharma agreed to acquire Catalyst Pharmaceuticals for about $4.1 billion in cash, adding three FDA-approved rare disease medicines to its portfolio and creating a direct entry into the U.S. market. The deal brings Catalyst’s marketed franchise into Angelini’s neurology strategy, with expected closing in the third quarter of 2026. Catalyst’s product lineup includes Firdapse for Lambert-Eaton myasthenic syndrome, Agamree for Duchenne muscular dystrophy, and Fycompa for certain seizure types. Catalyst reported 2025 revenue of about $589 million, a 19.8% increase over 2024, driven by growth in its rare neuromuscular assets. Angelini said the acquisition strengthens its global commercial infrastructure while supporting continued development of neurology-focused programs, including epilepsy candidates in active clinical trials.