X0306 4 2015-04-27 0 0001302573 OncoMed Pharmaceuticals Inc OMED 0001553333 Hoey Timothy C/O ONCOMED PHARMACEUTICALS, INC. 800 CHESAPEAKE DRIVE REDWOOD CITY CA 94063 0 1 0 0 SVP, Cancer Biology Common Stock 2015-04-27 4 M 0 5000 1.43 A 56230 D Common Stock 2015-04-27 4 S 0 3537 25.124 D 52693 D Common Stock 2015-04-27 4 S 0 3350 26.2034 D 49343 D Stock Option (Right to Buy) 1.43 2015-04-27 4 M 0 5000 0.00 D 2017-01-10 Common Stock 5000 30263 D Transaction made pursuant to a 10b5-1 trading plan adopted by the Reporting Person on March 26, 2015. Includes 20,000 restricted stock units. The Reporting Person is entitled to receive one (1) share of common stock for each one (1) restricted stock unit. Also includes 1,285 shares acquired under the Issuer's Employee Stock Purchase Plan on February 27, 2015. This transaction was executed in multiple trades in prices ranging from $24.86 to $25.43, inclusive. The price reported in Column 4 above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. This transaction was executed in multiple trades in prices ranging from $25.995 to $26.55, inclusive. The price reported in Column 4 above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. The option is fully vested and exercisable, subject to a limitation of 175,438 shares that can be issued to a single grantee in a 12-month period upon the exercise of awards under the Issuer's 2004 Stock Incentive Plan. /s/ Alicia J. Hager, Attorney-in-Fact for Timothy Hoey 2015-04-29