SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person* Simon Nicholas (Last) (First) (Middle) 101 MAIN STREET, SUITE 1210 (Street) CAMBRIDGE MA 02142 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 09/27/2018	3. Issuer Name and Ticker or Trading Symbol Gritstone Oncology, Inc. [ GRTS ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director 10% Owner Officer (give title below) Other (specify below)	5. If Amendment, Date of Original Filed (Month/Day/Year)
			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)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: 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
Series A Convertible Preferred Stock	(1)	(2)	Common Stock	1,565,216	(1)	I	See Footnote(3)
Series B Convertible Preferred Stock	(1)	(2)	Common Stock	668,896	(1)	I	See Footnote(3)

Explanation of Responses:

1. The shares of the Issuer's Preferred Stock automatically convert into shares of the Issuer's Common Stock, for no additional consideration, on a 1:1 basis immediately prior to the consummation of the Issuer's initial public offering.

2. The expiration date is not relevant to the conversion of these securities.

3. Consists of the shares held by Clarus Lifesciences III, L.P. ("Clarus"). Clarus Ventures III GP, L.P. ("GPLP"), as the sole general partner of Clarus may be deemed to beneficially own certain of the shares held by Clarus. The GPLP disclaims beneficial ownership of all shares held by Clarus in which the GPLP does not have an actual pecuniary interest. Clarus Ventures III, LLC ("GPLLC"), as the sole general partner of the GPLP, may be deemed to beneficially own certain of the shares held by Clarus. The GPLLC disclaims beneficial ownership of all shares held by Clarus in which it does not have an actual pecuniary interest. The Reporting Person, as an individual managing director of GPLLC disclaims beneficial ownership of all shares held of record by Clarus in which he does not have an actual pecuniary interest.

	/s/ Dana B. Johnson, Attorney-in-Fact for Nicholas Simon	09/27/2018
	** 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).
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