X0306 4 2015-06-02 0 0001491576 TESARO, Inc. TSRO 0001237289 SANDELL SCOTT D 1954 GREENSPRING DRIVE SUITE 600 TIMONIUM MD 21093 0 0 1 0 Common Stock 8854255 I See Note 1 Common Stock 2015-06-02 4 S 0 504 59.72 D 0 I See Note 2 Common Stock 2015-06-02 4 S 0 1500 57.5549 D 629 I See Note 3 Common Stock 2015-06-02 4 S 0 629 58.1299 D 0 I See Note 3 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. The shares are directly held by Rising River Partners, L.P. 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 Rising River Partners, L.P. in which the Reporting Person has no pecuniary interest. The Reporting Person is a member of the Board of Directors of New Enterprise Associates, LLC ("NEA LLC"), which is 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 LLC in which the Reporting Person has no pecuniary interest. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $57.13 to $57.86, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote (4) to this Form 4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $57.89 to $58.87, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote (5) to this Form 4. /s/ Sasha Keough, attorney-in-fact 2015-06-04