Tokyo-based Astellas Pharma is buying Cambridge, Mass.-based Mitobridge for a total of $390 million.

Astellas is pulling the trigger on an acquisition option from a partnership deal the two companies formed in 2013. Under that deal, the two companies collaborated on discovering and developing drugs that target mitochondrial function. The most advanced program from the collaboration is MA-0211, which is presently in Phase I clinical trials for Duchenne muscular dystrophy (DMD).

Astellas is an equity investor in Mitobridge already, and is paying $165.5 million in cash in addition to the $60 million in equity it already owns. There is also an additional $225 million in potential milestone payments.

John Carroll, with Endpoints News, writes, “For years now, Salk’s Ron Evans—a celebrated serial entrepreneur in scientific circles—has been concentrating on the potential of a new pathway for turning your average couch potato rodent into Mighty Mouse—without exercise…. A couple of years ago the biotech in-licensed preclinical tech developed by Evans on PPARd, a pathway he feels could trigger the health benefits of a rigorous exercise regime, without the actual exercise. Evans recently completed his preclinical work, saying he had perfected the approach in mice.”

The drug Evans identified was GW1516, which in a different version was being used by some athletes as an illicit performance enhancer. GlaxoSmithKline had rights to the drug, but dropped it over 10 years ago because of serious side effects, including cancer.

DMD is a rare muscle-wasting disease caused by mutations in the dystrophin gene. Dystrophin is a protein directly involved in muscle development. The disease mostly affects boys and is usually fatal at a young age, often in the 20s. Sarepta Therapeutics' Exondys 51 is the most well-known treatment for the disease, although it is only appropriate for about 13 percent of patients with a specific mutation, and its efficacy is controversial.

“Astellas has increased the involvement in mitochondrial drug discovery through its partnership with Mitobridge and the network of key scientists that the company has assembled,” said Yoshihiko Hatanaka, Astellas’ president and chief executive officer, in a statement. “The achievements resulting from the collaboration have exceeded our expectations including the rapid advancement of multiple programs. Through the acquisition of Mitobridge, Astellas accelerates our investment in diseases caused by mitochondria dysfunctions in order to deliver innovative new treatment options to patients.”

Although a specific timeline was not mentioned, closing is expected in the next several weeks. Other major shareholders of Mitobridge include MPM Capital and Longwood Funders Fund.

Mitobridge has 27 employees. It was formerly known as Mitokyne. It was founded with seed funding from MPM Capital in 2011, and in October 2013, closed a Series A round from MPM Capital, Longwood Fund, and Astellas Pharma.

“We at Mitobridge are delighted to become part of Astellas’ major initiative to develop new therapies for serious diseases,” said Kazumi Shiosaki, Mitobridge’s co-founder, president and chief executive officer, in a statement. “We are grateful for the tremendous support and guidance from Astellas, MPM Capital, and Longwood Fund that enabled Mitobridge to rapidly build an exciting pipeline. Mitobridge—as a subsidiary of Astellas—will now have additional resources to continue to advance and expand on its achievements to date.”