RuiYi Inc., a biotech based both in La Jolla and Shanghai, has received $15 million in Series B financing from a group of existing investors.

The privately held company, founded in 2008, has a class of drugs in development called monoclonal antibodies which help treat autoimmune disease. The funding will be primarily for the company’s lead asset, RYI-008, which treats rheumatoid arthritis.

Instead of starting out in the U.S., the company’s aim is to conduct its research, development and market entrance in China, CEO Paul Grayson said.

Investors include 5AM Ventures, Versant Ventures, Apposite Capital, Aravis SA, Merck Serono Ventures and SR One, the health care venture fund of drugmaker GlaxoSmithKline PLC.