Optimer prices underwritten public offering of common stock

Optimer Pharmaceuticals, Inc. (Nasdaq: OPTR) today announced the pricing of a previously announced underwritten public offering of 6,000,000 shares of its common stock, offered at a price to the public of $11.25 per share. The gross proceeds to Optimer from this offering are expected to be $67.5 million, before deducting the underwriting discounts and commissions and other estimated offering expenses payable by Optimer.  The offering is expected to close on or about February 16, 2011, subject to customary closing conditions. Optimer has also granted the underwriters a 30-day option to purchase at the public offering price up to an additional 900,000 shares of its common stock to cover overallotments, if any.

Jefferies & Company, Inc. is acting as the sole book-running manager for the offering. Baird, Canaccord Genuity Inc., JMP Securities, Needham & Company, LLC, and ThinkEquity LLC are acting as co-managers for the offering.  

Optimer anticipates using the net proceeds from the offering to prepare for the potential commercial launch of fidaxomicin in the United States, if approved, as well as for research and development activities, potential in-licenses or acquisitions, working capital and other general corporate purposes.