Arena Pharmaceuticals Inc. priced an underwritten public offering of 8.5 million common shares at $41.50 each.

The company expects to raise gross proceeds of about $352.8 million through the offering, which is expected to close March 26, subject to customary closing conditions.

The underwriters have a 30-day option to buy up to an additional 1,275,000 shares at the offering price.

Arena Pharmaceuticals plans to use net proceeds to develop its clinical candidates and for general corporate purposes.

Citigroup, Leerink Partners, Cantor Fitzgerald, Credit Suisse and RBC Capital Markets are acting as joint book-running managers for the offering, with Guggenheim Securities and JMP Securities as co-managers.

San Diego-based Arena Pharmaceuticals develops small molecule drugs for various therapeutic areas in the U.S. and Switzerland.