Blackstone ’s private equity funds have signed a definitive agreement to acquire Japan-based anti-rheumatism drugs manufacturer AYUMI Pharmaceutical from Unison Capital and M3.

Ayumi was established in 2015 through the integration of Santen Pharmaceutical’s anti-rheumatic drug business and Showa Yakuhin Kako’s medical business. It also focuses on orthopaedic therapeutic areas.

The announcement comes after Unison Capital said in December that it was exploring a sale of Ayumi and was working with JPMorgan Chase & Co to draw potential buyer interest in the company for a deal that may be worth around $1bn.

Ayumi Pharmaceutical president and CEO Ouchi Hikaru said: “Although we have already established a strong platform of growth in partnership with Unison Capital, from orthopaedic therapeutic areas to RA areas and further through the new introduction of biosimilar products, we will need more investment for future growth.”

“We look forward to working with the company to leverage Blackstone’s global footprint and expertise in this sector to help Ayumi meet the growing need for its RA and orthopaedic products.”

Ayumi’s flagship analgesic product Calonal is used to treat chronic pain in patients across numerous disease areas.

The acquisition of Ayumi represents the first control private equity investment by Blackstone in Japan after it established a local team in 2017 to expand focus beyond property transactions, Reuters reported.

A portfolio of first-in-line treatments is offered by the company through synthetic and biosimilar products prescribed to patients across all stages of RA diagnoses.

Blackstone senior managing director Atsuhiko Sakamoto said: “We look forward to working with the company to leverage Blackstone’s global footprint and expertise in this sector to help Ayumi meet the growing need for its RA and orthopaedic products, invest in new, cutting-edge treatments and products, and continue supporting the company’s mission of improving patient health.”

The transaction is expected to close in the second quarter of this year subject to regulatory approvals and customary closing conditions.