Japan’s Ministry of Health, Labour and Welfare has approved Viatris’ Wakix (pitolisant) for excessive daytime sleepiness (EDS) related to obstructive sleep apnoea syndrome (OSAS) and for narcolepsy types 1 and 2.

The approval covers patients with OSAS who continue to experience EDS while receiving treatment for airway obstruction.

It also applies to narcolepsy with and without cataplexy, a condition involving sudden muscle weakness.

Wakix is said to be the first histamine H3 receptor antagonist/inverse agonist to be authorised in Japan for these indications.

Viatris chief research and development (R&D) officer Philippe Martin said: “As Japan's first approved histamine H3 receptor antagonist/inverse agonist for these conditions, Wakix offers a much-needed novel treatment option for patients.

“This milestone marks an important advancement for sleep medicine in Japan and brings forward a treatment option that is not classified as a controlled substance.

“We continue to strengthen Viatris' innovative medicines portfolio in this strategically important market by investing in differentiated therapies for patients.”

The approval in Japan is based on encouraging domestic Phase III studies and supporting evidence from international clinical research.

Wakix is an orally administered therapy that modulates the brain’s sleep–wake pathways and is not classified as a controlled substance.

In Japan, pitolisant is licensed exclusively to Viatris by Bioprojet (Paris, France), the company that discovered the drug.

Wakix has previously received regulatory authorisation for narcolepsy in over 38 countries, including the US and countries in Europe, as well as for OSAS-related EDS in more than 29 European countries.

In Japan, the therapy received orphan drug designation for narcolepsy.

In December 2025, Viatris signed definitive agreements for the sale of its equity stake in Biocon Biologics to Biocon for $815m.