OncoMed Pharmaceuticals, Inc. Announces Closing of

REDWOOD CITY, Calif., July 23, 2013 (GLOBE NEWSWIRE) -- OncoMed Pharmaceuticals, Inc. (Nasdaq: OMED ), today announced the closing of its initial public offering of 5,520,000 shares of its common stock at an initial public offering price of $17.00 per share, which includes the exercise in full by the underwriters of their option to purchase up to 720,000 additional shares of common stock. OncoMed's common stock is listed on The NASDAQ Global Select Market under the trading symbol "OMED." All of the shares in the offering were offered by OncoMed.

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

A copy of the final prospectus relating to the offering may be obtained by contacting 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 offering was made solely by means of a prospectus. 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 other 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 other 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