VLST Corp., a Seattle biotech developing therapeutics for the treatment of autoimmune and inflammatory diseases, has raised an additional $5 million in venture capital financing, according to a SEC filing today. The company could raise another $10 million in the round, according to the filing.

Backers of the company — incubated at the Accelerator Corp. — include OVP Venture Partners, Arch Venture Partners, WRF Capital and others.  Xconomy’s Luke Timmerman notes that the company has raised about $50 million to date, with the new funds to be used to push ahead R&D efforts.

VLST is led by Marty Simonetti, the former CFO at Dendreon Corporation and ex-vice president of operations at at Amgen Inc.

With more than $100 million invested in domain name registrar Donuts; $30 million invested in medical device maker Kona Medical and $18 million invested in SEOMoz in recent weeks, the second quarter is shaping up to be a big one in the venture capital circles in Washington state.