‘Truly Transformational:’ Sosei Heptares Acquires Idorsia’s Pharmaceuticals Business in Japan and APAC (ex-China)

2 minute read | July.20.2023

Sosei Heptares has announced its acquisition for U.S.$466 million (JPY 65 billion) of Idorsia’s pharmaceuticals business in Japan and APAC (ex-China).

Orrick advised Sosei Heptares.

“This fully funded transaction is truly transformational and achieves one of our key strategic objectives, establishing Sosei Heptares as a fully integrated Japan-focused biopharmaceutical business, with growing commercial sales and an expected new product launch next year,” said Chris Cargill, President and CEO of Sosei Heptares.


Sosei Heptares is a fully integrated biopharmaceutical company focused on bringing life-changing medicines based on world-class science to patients globally. Its vision is to become one of Japan’s global biopharmaceutical champions.

Sosei Heptares has a leading development capability and a profitable and growing commercial operation in Japan, which it intends to expand into additional selected markets in the Asia-Pacific region.

Sosei Heptares is advancing a broad and deep pipeline of novel medicines created using its world-leading GPCR-targeted StaR® technology and structure-based drug design platform across multiple therapeutic areas, including neurology, immunology, gastroenterology and inflammatory diseases.

In addition, Sosei Heptares leveraged its unique discovery and development capabilities in multiple value-generating partnerships with world-leading biopharmaceutical companies, including Genentech (Roche), a British Multinational Pharmaceutical and Biotechnology Company, Lilly, Neurocrine Biosciences, Novartis, Pfizer, Sanofi and Takeda.

Sosei Heptares is headquartered in Tokyo, with corporate and R&D facilities in London and Cambridge, UK.


Headquartered in Switzerland, Idorsia is a biopharmaceutical company specializing in the discovery, development and commercialization of innovative small molecules, with the aim of transforming the horizon of therapeutic options.


This strategic transaction includes the rights in Japan and APAC (ex-China) to an exciting pipeline of medicines including Pivlaz® (clazosentan) which is commercially available in Japan for cerebral vasospasm, and daridorexant, for which filing in Japan is expected in 2023 for insomnia. The Japanese pharmaceutical market is the second-largest developed single market in the world, valued at U.S.$85 billion.

“The Japan pharmaceutical market, given its size, large ageing population and attractive high quality clinical development and regulatory environment is the key next step for Sosei Heptares' growth ambitions,” Cargill said. “We are confident that this transaction, which will be cash-flow positive in year one, will allow us to deliver significant value and benefits to all our key stakeholders.”

Following this transaction, Sosei Heptares has the breadth and depth of scale to accelerate its growth plans delivering important medicines to patients across key markets starting with Japan, and eventually, across other parts of APAC (ex-China). The newly enlarged group now employs over 370 people across all locations.


Orrick’s Ed Dyson, David Schulman, Hiroki Sugita, and Kayla Z. X. Southworth led a team advising Sosei Heptares that also included Tiffany Chiu Leung, Yuan Tian, Sakon Kuramoto, Yumiko Ohta, Anri Nakamoto, Kazuya Takeda, Masao Fujino, Miho Yamada, Sushila Nayak, Scott Morrison, Shinsuke Yakura, Charles Sheldon and Gargi Talukder.



Sosei Heptares news release

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