X0306 4 2015-01-05 0 0001302573 OncoMed Pharmaceuticals Inc OMED 0001553335 Dupont Jakob C/O ONCOMED PHARMACEUTICALS, INC. 800 CHESAPEAKE DRIVE REDWOOD CITY CA 94063 0 1 0 0 SVP & Chief Medical Officer Common Stock 2015-01-05 4 M 0 7500 4.56 A 29120 D Common Stock 2015-01-05 4 S 0 7500 23.00 D 21620 D Stock Option (Right to Buy) 4.56 2015-01-05 4 M 0 7500 0.00 D 2021-10-24 Common Stock 7500 164937 D Transaction made pursuant to a 10b5-1 trading plan adopted by the Reporting Person on May 27, 2014. 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. Includes 724 shares acquired under the Issuer's Employee Stock Purchase Plan on August 29, 2014. The option was immediately exercisable in full on October 24, 2011; however, the shares vest pursuant to the following schedule: Twenty Percent (20%) of the shares subject to the option vest on the first anniversary measured from October 1, 2011 (the "Vesting Commencement Date") and the remaining shares subject to the option vest in 48 successive, equal monthly installments thereafter on each monthly anniversary of the Vesting Commencement Date, subject to the Reporting Person's continued employment or service relationship with the Issuer on each such vesting date. /s/ Alicia J. Hager, Attorney-in-Fact for Jakob Dupont 2015-01-07