Form: 4

Statement of changes in beneficial ownership of securities

October 1, 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
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(Print or Type Responses)
1. Name and Address of Reporting Person *
JANNEY DANIEL
   2. Issuer Name and Ticker or Trading Symbol
SUTRO BIOPHARMA INC [STRO] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
ONE EMBARCADERO CENTER, SUITE 3700		 3. Date of Earliest Transaction (Month/Day/Year)
10/01/2018
(Street)

SAN FRANCISCO, CA 94111		 4. If Amendment, Date 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
(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   589,661 A (1) 589,661 I By Alta Partners VIII, L.P. (2)
Common Stock 10/01/2018   C   458,331 A (3) 1,047,992 I By Alta Partners VIII, L.P. (2)
Common Stock 10/01/2018   C   382,698 A (4) 1,430,690 I By Alta Partners VIII, L.P. (2)
Common Stock 10/01/2018   C   514,211 A (5) 1,944,901 I By Alta Partners VIII, L.P. (2)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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 B Preferred Stock (1) 10/01/2018   C     10,201,769   (1)   (1) Common Stock 589,661 $ 0 0 I By Alta Partners VIII, L.P. (2)
Series C Preferred Stock (3) 10/01/2018   C     12,387,324   (3)   (3) Common Stock 458,331 $ 0 0 I By Alta Partners VIII, L.P. (2)
Series D Preferred Stock (4) 10/01/2018   C     9,449,318   (4)   (4) Common Stock 382,698 $ 0 0 I By Alta Partners VIII, L.P. (2)
Series E Preferred Stock (5) 10/01/2018   C     18,698,578   (5)   (5) Common Stock 514,211 $ 0 0 I By Alta Partners VIII, L.P. (2)

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
JANNEY DANIEL
ONE EMBARCADERO CENTER, SUITE 3700
SAN FRANCISCO, CA 94111		   X   X    

Signatures

 /s/ Edward C. Albini as attorney-in-fact for Daniel Janney   10/01/2018
**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 B Preferred Stock automatically converted into 0.0578 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 Alta Partners VIII, L.P. ("Alta Partners). Alta Partners Management VIII, LLC ("Alta Management") is the general partner of Alta Partners. The reporting person, a member of the issuer's board of directors, is a managing director of Alta Management, and may be deemed to share voting and investment power over the securities held by Alta Partners. The reporting person disclaims beneficial ownership over such securities except to the extent of his 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.
(3) 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 IPO pursuant to the Registration Statement, and had no expiration date.
(4) 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.
(5) 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.

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