X0306 4 2013-05-28 0 0001491576 TESARO, Inc. TSRO 0001184592 SEIDENBERG BETH C C/O TESARO, INC. 1000 WINTER STREET, SUITE 3300 WALTHAM MA 02451 1 0 0 0 Common Stock 2013-05-28 4 J 0 9325 0 A 12321 D Common Stock 1652837 I See footnote Common Stock 139828 I See footnote As a result of a pro-rata distribution for no consideration by Kleiner Perkins Caufield & Byers XIV, LLC ("KPCB XIV"), a limited liability company in which the Reporting Person is a member. The shares are held directly by KPCB XIV. The managing member of KPCB XIV is KPCB XIV Associates, LLC ("KPCB XIV Associates"), of which the Reporting Person is a member. The voting and dispositive control over the shares is shared by the members of KPCB XIV Associates. The shares are held for convenience in the name of "KPCB Holdings, Inc. as nominee." On May 28, 2013, KPCB XIV distributed 368,800 shares previously held by it in a pro-rata distribution for no consideration. The Reporting Person disclaims beneficial ownership over all Issuer shares held for convenience in the name of "KPCB Holdings, Inc. as nominee," except to the extent of her pecuniary interest therein and this filing is not an admission that the Reporting Person is the beneficial owner of these shares for the purposes of Section 16 or for any other purpose. The shares are held directly by KPCB XIV Founders Fund, LLC ("KPCB XIV Founders"). The managing member of KPCB XIV Founders is KPCB XIV Associates, LLC ("KPCB XIV Associates"), of which the Reporting Person is a member. The voting and dispositive control over the shares is shared by the members of KPCB XIV Associates. The shares are held for convenience in the name of "KPCB Holdings, Inc. as nominee." On May 28, 2013, KPCB XIV Founders distributed 31,200 shares previously held by it in a pro-rata distribution for no consideration. /s/ Paul Vronsky, Attorney-in-Fact 2013-05-29