Italy-based Angelini Pharma has agreed to acquire Catalyst Pharmaceuticals in a deal valued at $4.1 billion, giving the company access to three approved rare disease treatments and enabling its entry into the U.S. market.
Under the agreement, Angelini will pay $31.50 per share for the Florida-based drugmaker. The companies said the transaction is expected to close in the third quarter of the year. The offer represents a premium over Catalyst’s recent trading prices, including a 21% premium compared with its share value on April 22 before reports of a potential sale emerged.
Catalyst, founded in 2002 and listed on Nasdaq in 2006, reported $589 million in sales in 2025, reflecting 20% annual growth. Earlier this year, the company projected revenue between $615 million and $645 million for 2026.
The acquisition gives Angelini control of Catalyst’s marketed portfolio, led by Firdapse, a treatment approved in 2018 for Lambert-Eaton myasthenic syndrome (LEMS), a rare neuromuscular autoimmune disorder. Catalyst said Firdapse generated approximately $358 million in sales in 2025, representing yearly growth of around 18%.
Firdapse had also been involved in patent litigation with Hetero USA after the company sought approval for a generic version before Catalyst’s patents expired. Catalyst announced that the dispute has now been settled, resolving all pending litigation between the companies before the case proceeded further.
Angelini will also obtain Agamree, a Duchenne muscular dystrophy therapy approved by the FDA in 2023 for patients aged two years and older. Catalyst holds U.S. rights to the drug through its partnership with Santhera. Agamree recorded U.S. sales of $117 million last year.
In addition, the acquisition includes Fycompa, an epilepsy treatment for which Catalyst obtained U.S. rights from Eisai in 2022. The company reported $113 million in Fycompa sales last year, though the product began facing generic competition during the fourth quarter of the year.
Angelini said the acquisition would be integrated into its Brain Health division as part of efforts to expand its rare neurological disease business.
“Entering the U.S. market will allow us to acquire the scale and capabilities needed to continue this journey,” Angelini Pharma CEO Sergio Marullo di Condojanni said in a statement.
Catalyst CEO Rich Daly said the combined businesses would create a stronger, scalable and robust rare disease platform and expand access to life-changing therapies worldwide. He also said the transaction provides shareholders with immediate cash value through the agreed premium.
Angelini has expanded its neuroscience and rare disease activities in recent years through partnerships and acquisitions. In February, the company entered a $120 million collaboration with Quiver Bioscience to advance novel therapies for genetic epilepsies. The company also signed a $550 million agreement last year involving a preclinical neurological asset from South Korean biotech Sovargen.
The Catalyst acquisition follows another Italian pharmaceutical transaction announced recently. Last week, Chiesi Group agreed to acquire KalVista Pharmaceuticals for $1.9 billion, gaining the hereditary angioedema treatment Ekterly.
Angelini Pharma has announced a major strategic move to acquire Catalyst Pharmaceuticals in a deal valued at approximately $4.1 billion. The acquisition positions Angelini to significantly expand its rare disease and specialty medicine portfolio while strengthening its global pharmaceutical presence.
Overview of the Angelini Acquisition
The agreement between Angelini and Catalyst Pharmaceuticals marks one of the most significant transactions in the rare disease sector. Through this acquisition, Angelini aims to integrate Catalyst’s commercial products and research pipeline into its growing international operations.
The deal reflects Angelini’s long-term strategy to invest in high-value therapeutic areas with strong unmet medical needs.
