Onyx Pharmaceuticals Announces 4.4M Share Public Offering of Common Stock

Onyx Pharmaceuticals, Inc.

today announced an underwritten public offering of 4,400,000 shares of its common stock. Onyx has also granted the underwriters a 30-day option to purchase up to an additional 660,000 shares of common stock offered in the public offering to cover overallotments, if any. The offering is expected to close on or about January 22, 2013, subject to customary closing conditions. Onyx intends to use the net proceeds from this offering to fund its clinical development programs, research and development activities, and sales and marketing activities to commercialize Kyprolis around the world, and for general corporate purposes, including working capital. BofA Merrill Lynch and Barclays are acting as joint book-running managers for this offering.