OncoMed Pharmaceuticals, Inc. Announces Pricing of

REDWOOD CITY, Calif., July 17, 2013 (GLOBE NEWSWIRE) -- OncoMed Pharmaceuticals, Inc. (Nasdaq: OMED ), today announced the pricing of its initial public offering of 4,800,000 shares of its common stock at a price to the public of $17.00 per share. The shares are expected to begin trading on The NASDAQ Global Select Market on Thursday, July 18, 2013 under the ticker symbol "OMED." All of the shares of common stock are being offered by OncoMed. In addition, OncoMed has granted the underwriters a 30-day option to purchase up to an additional 720,000 shares of common stock.

Jefferies LLC and Leerink Swann are acting as joint book-running managers for the offering. Piper Jaffray and BMO Capital Markets are acting as co-managers.

This offering is being made solely by means of a prospectus, copies of which may be obtained from Jefferies LLC, Equity Syndicate Prospectus Department, 520 Madison Avenue, 12th Floor, New York, NY 10022, or by calling 877-547-6340, or by e-mailing Prospectus_Department@Jefferies.com; or Leerink Swann LLC, Attention: Syndicate Department, One Federal Street, 37th Floor, Boston, MA 02110, by telephone at 1-800-808-7525 or by email at Syndicate@Leerink.com.

A registration statement relating to these securities was declared effective by the Securities and Exchange Commission on July 17, 2013. This press release shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of these securities in any state or jurisdiction in which such an offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction.

About OncoMed Pharmaceuticals, Inc.

OncoMed Pharmaceuticals is a clinical-stage company focused on discovering and developing novel therapeutics targeting cancer stem cells, or CSCs, which are the subpopulation of cells in a tumor responsible for driving growth and metastasis of the tumor. OncoMed has five anti-CSC product candidates in clinical development, including demcizumab (OMP-21M18, anti-DLL4), OMP-59R5 (anti-Notch2/3), OMP-52M51 (anti-Notch1), vantictumab (OMP-18R5, anti-Fzd7), and OMP-54F28 (Fzd8-Fc), which target key cancer stem cell signaling pathways including Notch and Wnt. OncoMed has two other antibodies in preclinical development with Investigational New Drug filings planned for as early as 2014. OncoMed is also pursuing discovery of additional novel anti-CSC product candidates. OncoMed has formed strategic alliances with Bayer Pharma AG and GlaxoSmithKline.

Investor Contacts: OncoMed Pharmaceuticals Shari Annes Investor Relations (650) 888-0902 Media Inquiries: BCC Partners Karen L. Bergman or Michelle Corral (650) 575-1509 or (415) 794-8662 or