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 *
BASKETT FOREST
   2. Issuer Name and Ticker or Trading Symbol
TESARO, Inc. [TSRO] 		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)
1954 GREENSPRING DRIVE, SUITE 600		 3. Date of Earliest Transaction (Month/Day/Year)
01/22/2019
(Street)

TIMONIUM, MD 21093		 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 01/22/2019   U   9,681,038 (1) D $ 75 0 I See Note 2 (2)
Common Stock 01/22/2019   U   739,517 (1) D $ 75 0 I See Note 3 (3)

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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

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
BASKETT FOREST
1954 GREENSPRING DRIVE
SUITE 600
TIMONIUM, MD 21093		     X    

Signatures

 /s/ Sasha Keough, attorney-in-fact   01/22/2019
**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) Tendered in connection with tender offer made by Adriatic Acquisition Corporation, a Delaware corporation ("Purchaser") and a wholly-owned subsidiary of GlaxoSmithKline plc, a public company organized under the laws of England and Wales ("Parent"), to purchase all of the issued and outstanding shares of TESARO, Inc., a Delaware corporation ("TESARO"), for $75.00 per share, pursuant to the terms of that certain Agreement and Plan of Merger, dated as of December 3, 2018 by and among TESARO, Purchaser, and Parent (the "Merger Agreement").
(2) The Reporting Person is a director of NEA 13 GP, LTD, which is the sole general partner of NEA Partners 13, L.P. ("NEA Partners 13"). NEA Partners 13 is the sole general partner of New Enterprise Associates 13, L.P. ("NEA 13"), the direct beneficial owner of the shares. The Reporting Person disclaims beneficial ownership within the meaning of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise of such portion of the shares of the Issuer held by NEA 13 in which the Reporting Person has no pecuniary interest.
(3) The Reporting Person is a director of NEA 15 GP, LLC, which is the sole general partner of NEA Partners 15-OF, L.P. ("NEA Partners 15-OF"). NEA Partners 15-OF is the sole general partner of New 15 Opportunity Fund, L.P. ("NEA 15-OF"), the direct beneficial owner of the shares. The Reporting Person disclaims beneficial ownership within the meaning of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise of such portion of the shares of the Issuer held by NEA 15-OF in which the Reporting Person has no pecuniary interest.

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