September 26, 2018 - Petree Daniel H - 3: Initial statement of beneficial ownership of securities

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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3235-0104

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(Print or Type Responses)

1. Name and Address of Reporting Person ^*

Petree Daniel H

2. Date of Event Requiring Statement (Month/Day/Year)
09/26/2018

3. Issuer Name and Ticker or Trading Symbol
SUTRO BIOPHARMA INC [STRO]

(Last)

(First)

(Middle)

C/O SUTRO BIOPHARMA, INC., 310 UTAH AVENUE, SUITE 150

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 Original Filed(Month/Day/Year)

(Street)

SOUTH SAN FRANCISCO, CA 94080

6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person

(City)

(State)

(Zip)

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)
No securities beneficially held	0	D

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.			SEC 1473 (7-02)
	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.

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 of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
1. Title of Derivative Security (Instr. 4)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	4. Conversion or Exercise Price of Derivative Security		6. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock Warrant (right to buy)	⁽¹⁾	⁽¹⁾	Common Stock	314	$ 5.808 ⁽²⁾	D
Stock Option (right to buy Common Stock)	⁽³⁾	03/24/2019	Common Stock	3,030	$ 5.09	D
Stock Option (right to buy Common Stock)	⁽³⁾	09/08/2019	Common Stock	826	$ 5.09	D
Stock Option (right to buy Common Stock)	⁽³⁾	02/08/2021	Common Stock	4,132	$ 4.36	D
Stock Option (right to buy Common Stock)	⁽³⁾	04/17/2022	Common Stock	4,545	$ 4.36	D
Stock Option (right to buy Common Stock)	⁽³⁾	09/19/2022	Common Stock	2,617	$ 4.36	D
Stock Option (right to buy Common Stock)	⁽³⁾	02/13/2023	Common Stock	578	$ 5.81	D
Stock Option (right to buy Common Stock)	⁽³⁾	02/13/2023	Common Stock	873	$ 5.81	D
Stock Option (right to buy Common Stock)	⁽³⁾	02/26/2024	Common Stock	2,124	$ 5.81	D
Stock Option (right to buy Common Stock)	⁽³⁾	02/26/2024	Common Stock	3,540	$ 5.81	D
Stock Option (right to buy Common Stock)	⁽⁴⁾	09/27/2025	Common Stock	1,456	$ 11.98	D
Stock Option (right to buy Common Stock)	⁽³⁾	09/27/2025	Common Stock	2,427	$ 11.98	D

Reporting Owners

Reporting Owner Name / Address	Relationships
Reporting Owner Name / Address	Director	10% Owner	Officer	Other
Petree Daniel H C/O SUTRO BIOPHARMA, INC. 310 UTAH AVENUE, SUITE 150 SOUTH SAN FRANCISCO, CA 94080	X

Signatures

/s/ Edward C. Albini as attorney-in-fact for Daniel H. Petree		09/26/2018
^**Signature of Reporting Person		Date

Explanation of Responses:

*	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).
(1)	The warrant is exercisable at any time at the holder's election on a one-for one basis and automatically terminates on the completion of the issuer's initial public offering if not earlier exercised.
(2)	The warrant has a net exercise provision under which the holder, in lieu of paying the exercise price in cash, can surrender the warrant and receive a net number of shares of common stock based on the fair market value of such stock at the time of exercise, after deducting the aggregate exercise price.
(3)	The option is fully vested.
(4)	The option vests as to 2.0833% of the total shares monthly, beginning on October 15, 2015, with 100% of the total shares vested and exercisable on September 15, 2019, subject to the reporting person's provision of service to the issuer on each vesting date.

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, See Instruction 6 for procedure.

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