Viatris Acquires Aculys Pharma, Gains Rights to CNS Therapies Pitolisant and Spydia in Japan
Key Insights
Viatris completed the acquisition of Aculys Pharma (search), securing exclusive rights to pitolisant for narcolepsy (search) and obstructive sleep apnea treatment in Japan, with regulatory filing planned by end of 2025.
The deal includes rights to Spydia (search) nasal spray, Japan's first intranasal anti-seizure medication approved for status epilepticus (search) in patients aged 2 years and older.
Phase 3 trials in Japanese patients demonstrated statistically significant improvements in excessive daytime sleepiness (search) for both narcolepsy (search) and OSAS indications.
Viatris Inc. has completed its acquisition of Aculys Pharma (search), Inc., a clinical-stage biopharmaceutical company, gaining exclusive development and commercialization rights to two central nervous system therapies in Japan and select Asia-Pacific markets. The transaction positions Viatris to address significant unmet medical needs in neurological conditions while leveraging its established commercial infrastructure in Japan.
Strategic Expansion in CNS Therapeutics
The acquisition brings two innovative assets to Viatris' portfolio: pitolisant, a selective histamine H3 receptor (search) antagonist/inverse agonist for sleep disorders, and Spydia (search) nasal spray for status epilepticus (search). According to Corinne Le Goff, Chief Commercial Officer at Viatris, "The acquisition of Aculys Pharma (search) leverages our deep commercial infrastructure in Japan and longstanding expertise in CNS, positioning us to bring these innovative treatments to more patients in need."
Pitolisant represents a significant opportunity in the Japanese market, where Viatris plans to file for marketing approval with the Ministry of Health, Labour and Welfare by the end of 2025. The drug targets excessive daytime sleepiness (search) and cataplexy (search) in adult patients with narcolepsy (search), as well as excessive daytime sleepiness associated with obstructive sleep apnea syndrome (search).
Positive Phase 3 Results Drive Regulatory Strategy
Recent Phase 3 clinical trials in Japanese patients demonstrated the efficacy of pitolisant across both indications. In the narcolepsy (search) trial, the primary endpoint of improvement in excessive daytime sleepiness (search) compared to placebo using the Epworth Sleepiness Scale was met, with statistically significant differences observed between treatment groups. The key secondary endpoint measuring cataplexy (search) attack frequency showed suppression effects comparable to prior global Phase 3 trials, with no serious adverse events noted.
The obstructive sleep apnea syndrome (search) trial evaluated pitolisant in Japanese patients experiencing residual excessive daytime sleepiness (search) despite CPAP therapy. After 12 weeks of treatment, patients receiving pitolisant scored significantly lower on the Epworth Sleepiness Scale compared to placebo (p=0.007). Safety and tolerability profiles remained consistent with global clinical studies across both indications.
First-in-Class Epilepsy Treatment
Spydia (search) nasal spray represents a breakthrough in Japanese epilepsy care, having received marketing approval in June 2025 as the first intranasal anti-seizure medication for status epilepticus (search) treatment. The formulation is available in 5 mg, 7.5 mg, and 10 mg strengths for patients aged 2 years and older, marking the first rescue medication approved for adult out-of-hospital use in Japan.
Originally developed by Neurelis (search), Inc., the diazepam-based therapy addresses a critical gap in emergency seizure management. While diazepam has been used in Japan for approximately 60 years primarily in injectable form, the intranasal formulation offers improved accessibility for acute seizure episodes.
Global Regulatory Footprint
Pitolisant has established a substantial international presence, with regulatory approval in 38 countries including the United States and European Union for narcolepsy (search) treatment as of end-2023. The European Medicines Agency approved the drug for narcolepsy with or without cataplexy (search) in 2016, expanding the indication to include excessive daytime sleepiness (search) associated with OSAS in 2021. The FDA approved pitolisant under the brand name Wakix for narcolepsy-related indications in 2019 and 2020.
Transaction Structure and Portfolio Integration
Under the acquisition agreement, Viatris made an upfront payment to Aculys Pharma (search) shareholders, with additional consideration contingent upon regulatory and commercial milestones, plus royalties on net sales. The deal expands Viatris' innovative product portfolio in Japan, which includes Effexor for generalized anxiety disorder (search) under regulatory review, and ongoing Phase 3 programs for selatogrel in acute myocardial infarction, Nefecon (search) in IgA nephropathy (search), and cenerimod in systemic lupus erythematosus (search).
The acquisition aligns with Viatris' strategy to target accretive regional business development opportunities that complement its core strengths across global markets. Aculys Pharma (search), founded on the philosophy of serving as a "Catalyst to Access," focuses on eliminating drug lag and drug loss in Japan while addressing social issues related to neurological and psychiatric diseases.