UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the
Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): June 29, 2016

TESARO, Inc.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code:  (339) 970-0900

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

o      Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o      Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o      Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o      Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Section 8 — Other Events

Item 8.01              Other Events.

On June 29, 2016, TESARO, Inc. (the “Company”) issued a press release announcing positive top-line results from a Phase 3 clinical trial of niraparib, an orally active and potent poly (ADP-ribose) polymerase, or PARP, inhibitor, for the treatment of patients with high grade serous, platinum sensitive, relapsed ovarian cancer, which the Company refers to as the NOVA trial. A copy of the press release announcing these results is attached to this Current Report on Form 8-K as Exhibit 99.1 and incorporated herein by reference.

Section 9 — Financial Statements and Exhibits

Item 9.01              Financial Statements and Exhibits.

(d)           Exhibits.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Dated:  June 29, 2016

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EXHIBIT INDEX

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