X0306 4 2015-09-08 0 0001491576 TESARO, Inc. TSRO 0001370087 Armitage James O C/O TESARO, INC. 1000 WINTER STREET, SUITE 3300 WALTHAM MA 02451 1 0 0 0 Common Stock 2015-09-08 4 P 0 500 54.632 A 1500 I By The Nancy E. Armitage Revocable Living Trust The reporting person's spouse is trustee of the trust. The reporting person disclaims beneficial ownership of these securities, and the filing of this report is not an admission that the reporting person is the beneficial owner of these securities for purposes of Section 16 or for any other purposes, except to the extent of his pecuniary interest therein. /s/ Joseph L. Farmer, Attorney-in-Fact 2015-09-09