Ownership Submission
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, Section 17(a) of the Public Utility Holding Company Act of 1935 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 *
CELGENE CORP /DE/
  2. Issuer Name and Ticker or Trading Symbol
SUTRO BIOPHARMA INC [STRO]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
86 MORRIS AVENUE
3. Date of Earliest Transaction (Month/Day/Year)
10/01/2018
(Street)

SUMMIT, NJ 07901
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   1,726,197 A (1) (2) (3) (4) 1,726,197 D  

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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 C-2 Redeemable Convertible Preferred Stock (1) 10/01/2018   C     8,338,892   (1)   (1) Common Stock 337,725 $ 0 0 D  
Series D Redeemable Convertible Preferred Stock (2) 10/01/2018   C     2,845,114   (2)   (2) Common Stock 115,227 $ 0 0 D  
Series D-2 Redeemable Convertible Preferred Stock (3) 10/01/2018   C     18,097,331   (3)   (3) Common Stock 758,278 $ 0 0 D  
Series E Redeemable Convertible Preferred Stock (4) 10/01/2018   C     18,726,075   (4)   (4) Common Stock 514,967 $ 0 0 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
CELGENE CORP /DE/
86 MORRIS AVENUE
SUMMIT, NJ 07901
       

Signatures

 /s/ David V. Elkins, EVP and Chief Financial Officer   10/02/2018
**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) Upon closing of the Issuer's initial public offering, each share of Series C-2 redeemable convertible preferred stock automatically converted into 0.0405 share of Common Stock without payment of further consideration. The shares had no expiration date.
(2) Upon closing of the Issuer's initial public offering, each share of Series D redeemable convertible preferred stock automatically converted into 0.0405 share of Common Stock without payment of further consideration. The shares had no expiration date.
(3) Upon closing of the Issuer's initial public offering, each share of Series D-2 redeemable convertible preferred stock automatically converted into 0.0419 share of Common Stock without payment of further consideration. The shares had no expiration date.
(4) Upon closing of the Issuer's initial public offering, each share of Series E redeemable convertible preferred stock automatically converted into 0.0275 share of Common Stock without payment of further consideration. The shares had no expiration date.

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