Kaken Pharmaceutical Co. Ltd. entered an agreement to develop and commercialize Corbus Pharmaceuticals Holdings Inc.'s treatment for two rare and serious autoimmune diseases in Japan.

Tokyo-based Kaken Pharmaceutical make an up front payment of $27 million to Corbus for an exclusive license to commercialize and market lenabasum in Japan for systemic sclerosis and dermatomyositis.

Dermatomyositis, which affects about 9,000 people in Japan, causes a skin rash and weakens muscles over time. Patients with systemic sclerosis suffer from thickening of skin and injuries to small arteries, and the disease affects 28,000 people in Japan.

Norwood, Mass.-based Corbus Pharmaceuticals will also be eligible to receive up to $173 million upon achievement of certain regulatory, development and sales milestones as well as double-digit royalties.

Lenabasum has been granted an orphan drug designation in the U.S. and EU for treating dermatomyositis.