Viatris has completed the acquisition of Aculys Pharma, a clinical stage biopharmaceutical company focused on commercialising innovative treatments for neurological conditions.

As part of the transaction, Viatris has acquired exclusive development and commercialisation rights for pitolisant and Spydia, two assets in the Central Nervous System (CNS) therapy area, in Japan.

Pitolisant, a selective/inverse agonist of the histamine H3 receptor, is already approved in 38 countries, including the US and the EU for the treatment of narcolepsy, and in 29 countries in the EU for the treatment of obstructive sleep apnea syndrome (OSAS).

Based on the strength of recent Phase 3 clinical trial results in Japanese patients and the positive benefit-risk profile established globally, Viatris is on track to file for marketing approval from the Ministry of Health, Labour and Welfare (MHLW) of Japan for the treatment of excessive daytime sleepiness (EDS) or cataplexy in adult patients with narcolepsy and for the treatment of excessive daytime sleepiness associated with OSAS by the end of 2025.

The transaction also includes exclusive rights in Japan and certain other markets in the Asia-Pacific region for Spydia Nasal Spray, which was approved in Japan in June 2025 for the treatment of status epilepticus.

Corinne Le Goff, Chief Commercial Officer, Viatris, said, "The acquisition of Aculys Pharma leverages our deep commercial infrastructure in Japan and longstanding expertise in CNS, positioning us to bring these innovative treatments to more patients in need.”

"The addition of pitolisant and Spydia to our portfolio of innovative products is strategically aligned with our commitment to grow in areas where we can make the greatest impact and is a great example of our business development strategy designed to complement our core strengths in markets across the world,” she added.

This acquisition further expands Viatris' portfolio of innovative products in Japan which includes Effexor for the treatment of generalized anxiety disorder (GAD) which is under regulatory review, selatogrel in Acute MI, Nefecon in IgA nephropathy, and cenerimod in systemic lupus erythematosus (SLE), all of which have pivotal Phase 3 trials currently on going and Tyrvaya in dry eye disease for which a Phase 3 trial is anticipated to start in 2026.

Under the terms of the acquisition agreement, Viatris has made an upfront payment to Aculys Pharma shareholders as consideration for the acquisition, with additional consideration contingent upon the achievement of specified regulatory and commercial milestones, and royalties on net sales.