Trius Therapeutics Inc. said it has sold 9.9 million shares of its stock, raising a total of $52 million for clinical trials, research and development, and other general corporate purposes.

The San Diego-based biopharmaceutical company announced on Jan. 26 that it would sell 8.6 million shares to the public at $5.25 each. On Jan. 30, the company said that its underwriters exercised in full their option to purchase an additional 1.3 million shares, also at a price of $5.25 per share.

Trius said it expected gross proceeds of $51.9 million, before deducting underwriting discounts, commissions and other offering expenses.

Citigroup and Piper Jaffray & Co. acted as joint book-running managers for the offering, with Canaccord Genuity Inc. and Ladenburg Thalmann & Co. Inc. acting as co-managers.

Trius is a 70-person company that focuses on developing and commercializing antibiotics for life-threatening infections. The company’s lead investigational drug, tedizolid phosphate, is in phase 3 clinical trials for the treatment of acute bacterial skin and skin structure infections. The drug is a second-generation oxazolidinone, which is a class of compounds often used as antibiotics.

Trius has earned a $5 million milestone payment from its partner Bayer HealthCare for achieving all efficacy and safety objectives from the first Phase 3 trial, which tested the oral dosage form of the drug.

Trius trades on Nasdaq under the symbol TSRX. Shares were at $5.46 on the afternoon of Jan. 31, down 3 percent from the previous day’s close.

— Kelly Quigley