Italy’s Angelini Pharma agreed to buy Catalyst Pharmaceuticals in an all-cash deal valuing the company at about $4.1 billion, paying $31.50 per share—an approximate 21% premium to the prior close. The acquisition marks Angelini’s first major move into the U.S. rare-disease market and adds an already commercialized portfolio of neurological medicines. Catalyst’s marketed assets include Firdapse (amifampridine) for Lambert-Eaton myasthenic syndrome and Agamree (vamorolone) for Duchenne muscular dystrophy, plus Fycompa (perampanel) for certain seizure types. Catalyst reported 2025 revenue of about $589 million, with the company projecting 2026 total revenue of $615 million to $645 million. Angelini said Catalyst will become a wholly owned subsidiary and is expected to close in the third quarter of 2026. The deal is positioned as part of Angelini’s broader “brain health” strategy, combining U.S. commercial infrastructure with rare neurology development plans.