Simpson Thacher is representing Blackstone in connection with the sale of Ayumi Pharmaceutical Corporation (“Ayumi”) to GNI Group Ltd. (“GNI”). The transaction was announced on June 5, 2026. The Firm also represented Blackstone on its acquisition of Ayumi in 2019 from Unison Capital, an independent private equity firm based in Japan, and M3, Inc., a medical information site business.
Ayumi is a specialty pharmaceutical company in Japan focused on rheumatology, orthopedics, pain management and contract manufacturing services. GNI is a global biopharmaceutical company headquartered in Japan with operations spanning Japan, China, the United States, and Australia, engaged in pharmaceutical development and commercialization, drug discovery, and medical technology businesses.
The Simpson Thacher team includes Anthony King, Sonya Ho, Min Park and Xuechun Wen (M&A); Makiko Harunari, Atsushi Usui and Chenyu Cui (Banking & Credit); Vanessa Burrows, Alison Peters, Rebecca L. Rose and Jacob Madden (Healthcare); Étienne Renaudeau, Kelly Karapetyan, Nathaniel Bronstein and Nabi Can Acar (Antitrust); and Boli Chen and Kaiyan Qi (M&A – Beijing).