Initial Statement of Beneficial Ownership (3)

FORM 3	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES	OMB APPROVAL OMB Number: 3235-0104 Estimated average burden hours per response... 0.5
	Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

1. Name and Address of Reporting Person * Li Yvonne	2. Date of Event Requiring Statement (MM/DD/YYYY) 3/16/2018	3. Issuer Name and Ticker or Trading Symbol OncoMed Pharmaceuticals Inc [OMED]
(Last)        (First)        (Middle) C/O ONCOMED PHARMACEUTICALS, INC., 800 CHESAPEAKE DRIVE	4. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director                            _____ 10% Owner ___ X ___ Officer (give title below)          _____ Other (specify below) See Remarks /
(Street) REDWOOD CITY, CA 94063        (City)              (State)              (Zip)	5. If Amendment, Date Original Filed (MM/DD/YYYY)	6. Individual or Joint/Group Filing (Check Applicable Line) _ X _ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1.Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock	64952   (1)	D

Table II - Derivative Securities Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security (Instr. 4)	2. Date Exercisable and Expiration Date (MM/DD/YYYY)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Option (Right to Buy)	(2)	12/4/2018	Common Stock	1017	$3.42	D
Stock Option (Right to Buy)	(2)	3/14/2023	Common Stock	15571	$8.55	D
Stock Option (Right to Buy)	(2)	7/16/2023	Common Stock	5000	$17	D
Stock Option (Right to Buy)	(3)	12/17/2024	Common Stock	35000	$21.18	D
Stock Option (Right to Buy)	(4)	12/26/2025	Common Stock	30000	$21.43	D
Stock Option (Right to Buy)	(5)	1/2/2027	Common Stock	45000	$7.66	D
Stock Option (Right to Buy)	(6)	4/22/2027	Common Stock	50000	$3.73	D
Stock Option (Right to Buy)	(7)	10/6/2027	Common Stock	26666	$4.36	D
Stock Option (Right to Buy)	(8)	1/3/2028	Common Stock	55000	$3.98	D

Explanation of Responses:
(1)	Includes 45,834 Restricted Stock Units ("RSUs"). The Reporting Person is entitled to receive one (1) share of common stock for each one (1) RSU upon the vesting thereof.
(2)	The option is fully vested and exercisable.
(3)	The option vests with respect to 1/48 of the shares subject thereto on each monthly anniversary of December 18, 2014, subject to the Reporting Person's continued employment or service relationship with the Issuer on each such vesting date.
(4)	The option vests with respect to 1/48 of the shares subject thereto on each monthly anniversary of December 27, 2015, subject to the Reporting Person's continued employment or service relationship with the Issuer on each such vesting date.
(5)	The option vests with respect to 1/48 of the shares subject thereto on each monthly anniversary of January 3, 2017, subject to the Reporting Person's continued employment or service relationship with the Issuer on each such vesting date.
(6)	The option vests with respect to 1/48 of the shares subject thereto on each monthly anniversary of April 23, 2017, subject to the Reporting Person's continued employment or service relationship with the Issuer on each such vesting date.
(7)	The option vests with respect to 1/48 of the shares subject thereto on each monthly anniversary of October 7, 2017, subject to the Reporting Person's continued employment or service relationship with the Issuer on each such vesting date.
(8)	The option vests with respect to 1/48 of the shares subject thereto on each monthly anniversary of January 4, 2018, subject to the Reporting Person's continued employment or service relationship with the Issuer on each such vesting date.

Remarks: Vice President, Finance, Controller and Administration

Reporting Owners
Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Li Yvonne C/O ONCOMED PHARMACEUTICALS, INC. 800 CHESAPEAKE DRIVE REDWOOD CITY, CA 94063			See Remarks

Signatures
/s/ Alicia J. Hager, Attorney-in-Fact for Yvonne Li		3/20/2018
** Signature of Reporting Person		Date

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
*	If the form is filed by more than one reporting person, see Instruction 5(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note:	File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.