Form: 4

Statement of changes in beneficial ownership of securities

October 3, 2018

FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN 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
OMB APPROVAL
OMB Number: 3235-0287
Estimated average burden hours per response... 0.5

(Print or Type Responses)
1. Name and Address of Reporting Person *
Skyline Venture Partners V LP
   2. Issuer Name and Ticker or Trading Symbol
SUTRO BIOPHARMA INC [STRO] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
525 UNIVERSITY AVENUE		 3. Date of Earliest Transaction (Month/Day/Year)
10/01/2018
(Street)

PALO ALTO, CA 94301		 4. If Amendment, Date Original Filed(Month/Day/Year)
 6. Individual or Joint/Group Filing(Check Applicable Line)
___ Form filed by One Reporting Person
_X_ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)		 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)		 4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)		 5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)		 6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)		 7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 10/01/2018   C   925,578 A (1) 925,578 I By Skyline Venture Partners V, L.P. (2)
Common Stock 10/01/2018   C   520,264 A (3) 1,445,842 I By Skyline Venture Partners V, L.P. (2)
Common Stock 10/01/2018   C   514,211 A (4) 1,960,053 I By Skyline Venture Partners V, L.P. (2)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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. SEC 1474 (9-02)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)		 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)		 5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)		 6. Date Exercisable and Expiration Date
(Month/Day/Year)		 7. Title and Amount of Underlying Securities
(Instr. 3 and 4)		 8. Price of Derivative Security
(Instr. 5)		 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)		 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)		 11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Series C Preferred Stock (1) 10/01/2018   C     25,015,635   (1)   (1) Common Stock 925,578 $ 0 0 I By Skyline Venture Partners V, L.P. (2)
Series D Preferred Stock (3) 10/01/2018   C     12,846,023   (3)   (3) Common Stock 520,264 $ 0 0 I By Skyline Venture Partners V, L.P. (2)
Series E Preferred Stock (4) 10/01/2018   C     18,698,578   (4)   (4) Common Stock 514,211 $ 0 0 I By Skyline Venture Partners V, L.P. (2)

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Skyline Venture Partners V LP
525 UNIVERSITY AVENUE
PALO ALTO, CA 94301		     X    
Skyline Venture Management V, LLC
525 UNIVERSITY AVENUE
PALO ALTO, CA 94301		     X    
KANEKO YASUNORI
525 UNIVERSITY AVENUE
PALO ALTO, CA 94301		     X    

Signatures

 Skyline Venture Partners V, L.P. By: Skyline Venture Management V, LLC Its: General Partner /s/ Kerensa Kenny, Attorney-in-Fact   10/03/2018
**Signature of Reporting Person Date
 Skyline Venture Management V, LLC /s/ Kerensa Kenny, Attorney-in-Fact   10/03/2018
**Signature of Reporting Person Date
 Yasunori Kaneko /s/ Kerensa Kenny, Attorney-in-Fact   10/03/2018
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(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) Each share of the issuer's Series C Preferred Stock automatically converted into 0.0370 share of the issuer's Common Stock on October 1, 2018 in connection with the closing of the issuer's sale of its Common Stock in its firm commitment initial public offering (the "IPO") pursuant to a registration statement on Form S-1 (File No. 333-227103) under the Securities Act of 1933, as amended (the "Registration Statement"), and had no expiration date.
(2) These securities are held of record by Skyline Venture Partners V, L.P. ("Skyline L.P."). Skyline Venture Management V, LLC ("Skyline Management") is the general partner of Skyline L.P. John G. Freund and Yasunori Kaneko, are the managing directors of Skyline Management, and each may be deemed to share voting and investment power over the securities held by Skyline L.P. and disclaims beneficial ownership over such securities except to the extent of their pecuniary interest therein, and the inclusion of these securities in this report shall not be deemed an admission of beneficial ownership of the reported securities for purposes of Section 16 or for any other purposes. Mr. Freund is a director of the Issuer and, accordingly, files separate Section 16 reports.
(3) Each share of the issuer's Series D Preferred Stock automatically converted into 0.0405 share of the issuer's Common Stock on October 1, 2018 in connection with the closing of the issuer's sale of its Common Stock in its IPO pursuant to the Registration Statement, and had no expiration date.
(4) Each share of the issuer's Series E Preferred Stock automatically converted into 0.0275 share of the issuer's Common Stock on October 1, 2018 in connection with the closing of the issuer's sale of its Common Stock in its IPO pursuant to the Registration Statement, and had no expiration date.

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

Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB number.