Astellas Pharma is selling patents relating to type 2 diabetes drugs to a fund that acquires royalty interests, in a move that will bring in $609 million for the Japanese drugmaker.

The fund, called Royalty Pharma, will own patents and have the royalty rights relating to the use of dipeptidyl peptidase IV (DPP-4) inhibitors. The patents belong to Prosidion, a UK unit of OSI Pharmaceuticals, which Astellas bought last year for $3.54 billion.

In July 2004, Prosidion acquired a portfolio of medical use patents related to the use of DPP-4 inhibitors and a number of non-exclusive licenses to these patents have been granted to big pharmaceutical companies. The leading DDP-4 inhibitors are Merck & Co’s Januvia (sitagliptin), Novartis’s Galvus (vildagliptin) and Bristol-Myers Squibb/AstraZeneca’s Onglyza (saxagliptin).

"The sale of this large, passive, non-core financial asset will free up capital for reinvestment in strategic initiatives," Astellas chief executive Yoshihiko Hatanaka said. The Tokyo-headquartered group noted that Prosidion's assets include two drug candidates for diabetes and obesity and certain R&D capabilities. It will "continue to review strategic alternatives for these assets".

Royalty has got interests in several biopharma products, including Abbott Laboratories' Humira (adalimumab), bought from AstraZeneca for $700 million, and Johnson & Johnson/Merck & Co's Remicade (infliximab), acquired from New York University for $650 million.