Achaogen Inc. priced an underwritten public offering of 6.5 million common shares at a per-share price of $13.50 for $87.8 million in gross proceeds.

The company has granted the underwriters an option to buy up to an additional 975,000 shares.

Achaogen intends to use the net proceeds to fund the ongoing development and preparation for potential commercialization of plazomicin. The remaining net proceeds will be used for working capital and general corporate purposes, including research and development of additional product candidates.

The offering is expected to close Dec. 19, subject to satisfaction of customary closing conditions.

Leerink Partners LLC, Stifel and Guggenheim Securities LLC are acting as joint book-running managers for the offering. SunTrust Robinson Humphrey Inc. is acting as lead manager for the offering.