Shares of Omeros Corp. (OMER) - Get Report were down 7.6% to $19.22 in premarket trading on Tuesday, Aug. 22, after the Seattle firm on Monday said it wrapped up an underwritten public offering of 3 million shares priced on Aug. 14 at $22.75 apiece. The company received net proceeds of about $63.6 million after subtracting underwriting fees and discounts and other expenses.

Omeros has given Cantor Fitzgerald & Co. a 30-day option to purchase up to 450,000 additional shares.

Omeros said it plans to use the net proceeds for general corporate purposes, including funding research and development for its OMS721 programs and clinical trials, pre-clinical studies, manufacturing and other costs in connection with with advancing its product candidates toward Biologic License Application and New Drug Application submissions. The proceeds could also be used for debt repayment and acquisitions, among others.

Among the other biotech movers were Juno Therapeutics Inc. (JUNO) , down 2.8% to $26.07, and Vertex Pharmaceuticals Inc. (VRTX) - Get Report , up nearly 1% to $150.45.

More of What's Trending on TheStreet: