8-K

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): February 19, 2015

TESARO, Inc.

(Exact name of registrant as specified in its charter)

Delaware (state or other jurisdiction of
incorporation) 001-35587 (Commission File Number) 27-2249687 (I.R.S. Employer Identification No.)

1000 Winter Street Suite 3300 Waltham, Massachusetts	02451
(Address of principal executive offices)	(Zip Code)

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

(Former name or former address, if changed since last report)

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 2 — Financial Information

Item 2.02              Results of Operations and Financial Condition.

On February 19, 2015, TESARO, Inc. issued a press release announcing its operating results for the quarter and year ended December 31, 2014.  A copy of the press release is attached to this current report as Exhibit 99.1 and is incorporated herein by reference.  TESARO, Inc. has scheduled a conference call and webcast for 4:15 p.m. Eastern time on February 19, 2015 to discuss its operating results for the quarter and year ended December 31, 2014, and slides for that call are attached to this report as Exhibit 99.2 and are incorporated herein by reference.

The information contained in this report, including Exhibit 99.1 and Exhibit 99.2, is being furnished to the Securities and Exchange Commission and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to liabilities under that section.  Furthermore, such information shall not be deemed to be incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such filing.

Section 9 — Financial Statements and Exhibits

Item 9.01              Financial Statements and Exhibits.

(d)           Exhibits.

Exhibit No.	Description
99.1	TESARO, Inc. press release dated February 19, 2015 announcing operating results for the quarter and year ended December 31, 2014.
99.2	TESARO, Inc. slides for February 19, 2015 conference call and webcast for the quarter and year ended December 31, 2014.

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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.

	TESARO, Inc.
	By:	/s/ Timothy R. Pearson
		Timothy R. Pearson
		Executive Vice President and Chief Financial Officer
Dated: February 19, 2015

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EXHIBIT INDEX

Exhibit No.	Description
99.1	TESARO, Inc. press release dated February 19, 2015 announcing operating results for the quarter and year ended December 31, 2014.
99.2	TESARO, Inc. slides for February 19, 2015 conference call and webcast for the quarter and year ended December 31, 2014.

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EX-99.1

Exhibit 99.1

FOR RELEASE ON FEBRUARY 19, 2015 AT 4:01 PM ET

TESARO ANNOUNCES FOURTH-QUARTER 2014 OPERATING RESULTS

·Enrollment in niraparib NOVA non-gBRCA cohort on track to complete during Q1 2015

·New QUADRA trial of niraparib for the treatment of ovarian cancer to begin in Q1 2015

·U.S. FDA PDUFA action date for oral rolapitant is September 5, 2015

·Cash and cash equivalents totaled approximately $257 Million as of December 31, 2014

WALTHAM, MA, February 19, 2015 — TESARO, Inc. (NASDAQ: TSRO), an oncology-focused biopharmaceutical company, today reported financial results for fourth-quarter and full-year 2014 and provided an update on the Company’s pipeline programs.

“TESARO continues to make significant progress in advancing its pipeline of product candidates and in preparing for a commercial launch of rolapitant in the U.S. during the fourth quarter of 2015,” said Lonnie Moulder, CEO of TESARO. “We are committed to improving the treatment options for women with ovarian cancer and, as such, we are executing a comprehensive development program that includes patients, regardless of germline-BRCA mutation status, in both the treatment and maintenance settings. We continue to receive positive feedback from investigators regarding the breadth and potential of the niraparib program, and we look forward to initiating our QUADRA study for the treatment of patients with recurrent ovarian cancer this quarter. We also remain on track to complete enrollment of the non-germline BRCA cohort of patients within our Phase 3 NOVA trial during this quarter, and we expect the first data from NOVA to become available in 2015.”

Recent Business Highlights

·The New Drug Application (NDA) for oral rolapitant is under review by the U.S. Food and Drug Administration (FDA), with a PDUFA goal date of September 5, 2015.

·A clinical trial is ongoing to compare the plasma exposure of the intravenous (IV) and oral formulations of rolapitant.

·Preparations are ongoing to initiate a new trial of niraparib (QUADRA) in patients with ovarian cancer who have received three or more prior lines of prior chemotherapy. Endpoints will include objective response rate (ORR) and duration of response for the entire population, as well as platinum sensitive, platinum resistant, germline BRCA and homologous recombination deficiency (HRD) patient subsets.  This trial is anticipated to initiate during the first quarter of 2015.

·A strategy to incorporate a prospectively-defined biomarker (HRD) into the ongoing NOVA trial has been defined with FDA, and an HRD assay will be used to analyze tumor samples from patients who enroll in the niraparib ovarian clinical program.

·Patient enrollment continues in the Phase 3 BRAVO trial of niraparib, and planning continues to support initiation of additional clinical trials of niraparib in the small cell lung cancer and ovarian cancer settings.

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·Patient enrollment continues in the Phase 1 study of niraparib plus temozolomide in patients with Ewing’s sarcoma.

·The clinical activity of a fractionated dose of TSR-011 continues to be evaluated in ALK-positive and TRK-positive patients, and a controlled release formulation is now available for evaluation in the ongoing Phase 1 study.

·Preclinical studies of TSR-042 (our anti-PD-1 antibody candidate) and our clinical antibody candidates targeting TIM-3 and LAG-3 are underway in collaboration with AnaptysBio.

Fourth-Quarter 2014 Financial Results

·TESARO reported a net loss of $47.9 million, or $1.33 per share, for the fourth quarter of 2014, compared to a net loss of $23.3 million, or $0.72 per share, for the fourth quarter of 2013.

·Research and development expenses increased to $29.8 million for the fourth quarter of 2014, compared to $18.9 million for the fourth quarter of 2013, driven primarily by higher costs related to expanded development activities and increased headcount.

·General and administrative expenses increased to $7.4 million for the fourth quarter of 2014, compared to $4.5 million for the fourth quarter of 2013, primarily related to increased headcount, higher professional service fees and pre-launch commercial activities in support of oral rolapitant.

·Acquired in-process research and development expenses totaled $7.0 million for the fourth quarter of 2014 and included a milestone payment related to rolapitant and an upfront payment related to our immuno-oncology portfolio.

·Operating expenses as described above include total non-cash stock-based compensation expense of $3.1 million for the fourth quarter of 2014, compared to $2.7 million for the fourth quarter of 2013.

·Net interest expense increased to $3.7 million for the fourth quarter of 2014, primarily due to the accrual of interest payable and the amortization of the debt discount associated with the convertible notes issued in September 2014.

·As of December 31, 2014, TESARO had approximately $256.9 million in cash and cash equivalents and approximately 36.1 million outstanding shares of common stock.  TESARO continues to expect average cash utilization to be in the low-$40 million range per quarter during the first half of 2015.

Full-Year 2014 Financial Results

·TESARO reported a net loss of $171.0 million, or $4.79 per share, for 2014, compared to a net loss of $92.4 million, or $2.93 per share, for 2013.

·Research and development expenses increased to $118.4 million for 2014, compared to $75.7 million for 2013, driven primarily by higher costs related to our expanded development activities.

·Acquired in-process research and development expenses totaled $24.9 million for 2014 and included milestone and upfront payments related to rolapitant, niraparib, and our immuno-oncology portfolio, compared to $1.9 million for 2013, which included a milestone payment related to niraparib.

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·General and administrative expenses increased to $23.9 million for 2014, compared to $14.8 million for 2013, primarily related to increased headcount, higher professional service fees and pre-launch commercial activities in support of oral rolapitant.

·Operating expenses as described above include total non-cash stock-based compensation expense of $11.7 million for 2014, compared to $7.8 million in 2013.

·Net interest expense increased to $3.8 million for 2014, primarily due to the accrual of interest payable and the amortization of the debt discount associated with the convertible notes issued in September 2014.

Corporate Objectives

TESARO anticipates achieving the following key objectives:

·Continue commercial preparations in support of the potential U.S. launch of rolapitant in Q4 2015, pending regulatory approval;

·Initiate an additional supportive safety study of IV rolapitant during Q1 2015;

·Complete the study comparing the bioequivalence of oral rolapitant to IV rolapitant in mid-2015;

·Submit the NDA for IV rolapitant following regulatory approval of oral rolapitant;

·Finish enrollment of the expanded non-germline BRCA cohort within the Phase 3 NOVA trial of niraparib during Q1 2015;

·Initiate the QUADRA trial of niraparib as a treatment for patients with ovarian cancer who have received three or more prior lines of therapy during Q1 2015;

·Report initial data from the Phase 3 NOVA trial of niraparib during 2015;

·Continue to enroll the Phase 3 BRAVO trial of niraparib in breast cancer patients with germline BRCA mutations throughout 2015;

·Initiate trials of niraparib in first line ovarian cancer maintenance (PRIMA) and small cell lung cancer in 2H 2015;

·Evaluate the clinical activity of a controlled release formulation of TSR-011 within the ongoing Phase 1 study;

·Advance the development of TSR-042 (anti-PD-1 antibody) to support submission of an Investigational New Drug (IND) application to the U.S. FDA in late 2015; and

·Advance the IND enabling studies for the anti-TIM-3 and anti-LAG-3 clinical candidates.

Today’s Conference Call and Webcast

TESARO will host a conference call to discuss the Company’s fourth quarter operating results today at 4:15 p.m. Eastern time. The accompanying slide presentation and live webcast of the conference call can be accessed by visiting the TESARO website at www.tesarobio.com. The call can be accessed by dialing (877) 853-5334 (U.S. and Canada) or (970) 315-0307 (international). A replay of the webcast will be archived on the Company’s website for 30 days following the call.

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About TESARO

TESARO is an oncology-focused biopharmaceutical company dedicated to improving the lives of cancer patients by acquiring, developing and commercializing safer and more effective therapeutics. For more information, visit www.tesarobio.com.

Investor/Media Contact:

Jennifer Davis

Sr. Director, Corporate Development & Investor Relations

+1.781.325.1116 or jdavis@tesarobio.com

To the extent that statements contained in this press release are not descriptions of historical facts regarding TESARO, they are forward-looking statements reflecting the current beliefs and expectations of management made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Words such as “may,” “will,” “expect,” “anticipate,” “estimate,” “intend,” and similar expressions (as well as other words or expressions referencing future events, conditions or circumstances) are intended to identify forward-looking statements. Examples of forward looking statements contained in this press release include, among others, statements regarding our plans regarding future clinical trials with niraparib, the estimated time periods when we expect clinical trials to commence or be completed and statements regarding our expectations about the timing of both the selection of clinical candidates from our immune-oncology programs and the commencement of clinical testing for those candidates. Forward-looking statements in this release involve substantial risks and uncertainties that could cause our research and pre-clinical development programs, clinical development programs, future results, performance or achievements to differ significantly from those expressed or implied by the forward-looking statements. Such risks and uncertainties include, among others, the uncertainties inherent in the initiation of future clinical trials, availability of data from ongoing clinical trials, expectations for regulatory approvals, patient accrual rates for clinical trials, certain expenditures and other matters that could affect the availability or commercial potential of our drug candidates. TESARO undertakes no obligation to update or revise any forward-looking statements. For a further description of the risks and uncertainties that could cause actual results to differ from those expressed in these forward-looking statements, as well as risks relating to the business of the Company in general, see TESARO’s Annual Report on Form 10-K for the year ended December 31, 2013, and Quarterly Report on Form 10-Q for the quarter ended September 30, 2014.

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TESARO, Inc.

Unaudited Condensed Consolidated Statements of Operations

(in thousands, except per share amounts)

	Three Months Ended December 31,						Twelve Months Ended December 31,
	2013			2014			2013			2014
Expenses:
Research and development (1)	$	18,882		$	29,814		$	75,725		$	118,425
General and administrative (1)	4,465			7,397			14,780			23,935
Acquired in-process research and development	—			7,000			1,940			24,900
Total expenses	23,347			44,211			92,445			167,260
Loss from operations	(23,347		)	(44,211		)	(92,445		)	(167,260		)
Interest income (expense), net	7			(3,724		)	83			(3,752		)
Net loss	$	(23,340	)	$	(47,935	)	$	(92,362	)	$	(171,012	)
Net loss per share applicable to common stockholders - basic and diluted	$	(0.72	)	$	(1.33	)	$	(2.93	)	$	(4.79	)
Weighted-average number of common shares used in net loss per share applicable to common stockholders - basic and diluted	32,597			36,071			31,559			35,739

(1) Expenses include the following amounts of non-cash stock-based compensation expense:

Research and development	$	655	$	1,403	$	2,034	$	4,954
General and administrative	2,026		1,742		5,725		6,729

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TESARO, Inc.

Unaudited Condensed Consolidated Balance Sheets

(in thousands)

	December 31, 2013		December 31, 2014
Assets
Current assets:
Cash and cash equivalents	$	130,310	$	256,861
Other current assets	4,029		1,735
Total current assets	134,339		258,596
Property and equipment, net	440		1,022
Other assets	799		4,284
Total assets	$	135,578	$	263,902
Liabilities and stockholders’ equity
Current liabilities:
Accounts payable	$	1,869	$	6,089
Accrued expenses	10,541		16,750
Other current liabilities	13		1,526
Total current liabilities	12,423		24,365
Convertible notes, net	—		115,481
Other non-current liabilities	3		—
Total liabilities	12,426		139,846
Commitments and contingencies
Total stockholders’ equity	123,152		124,056
Total liabilities and stockholders’ equity	$	135,578	$	263,902

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EX-99.2

Exhibit 99.2

Fourth-Quarter and Full-Year 2014 Results February 19, 2015

Safe Harbor Statement Statements made in this presentation about TESARO, Inc. that are not descriptions of historical facts are forward-looking statements reflecting the current beliefs and expectations of management. Forward-looking statements are sometimes identified by words such as “plan,” “may,” “will,” “expect,” and similar expressions referencing future events, conditions or circumstances. These forward-looking statements involve substantial risks and uncertainties that could cause our clinical development programs, future results, performance or achievements to differ significantly from those expressed or implied by the forward-looking statements, as a result of various factors, including, without limitation, the risks described in our Annual Report on Form 10-K for the year ended December 31, 2013 and our subsequent filings with the SEC. TESARO, Inc. undertakes no obligation to update or revise any forward-looking statement for any reason.

Lonnie Moulder Chief Executive Officer

CINV: chemotherapy-induced nausea & vomiting Market opportunity projections are based upon Company estimates IND: Investigational new drug application KOL: Key opinion leader TESARO Is Positioned for Success Cash and equivalents of ~$257M as of 12/31/2014 Approximately 36.1 million shares outstanding as of 12/31/2014 Well Capitalized Commercial, development and regulatory experience in oncology Commercial leadership team now in place Relationships with KOLs and national oncology networks Experienced Team Differentiated Pipeline Rolapitant: Unmet market need that can be addressed via education and adherence to existing guidelines Niraparib: Broad development program underway with initial Phase 3 data expected in 2015 TSR-011: Phase 1 activity and favorable tolerability in ALK-positive NSCLC patients TSR-042: IND filing planned for late 2015 Anti-TIM-3, anti-LAG-3 and other mAb programs advancing Large Peak Target Market Opportunities Rolapitant: $1.5B U.S. CINV market Niraparib: $6B WW initial indications

Tim Pearson Chief Financial Officer

Q4 2014 Financial Results Three Months Ended December 31, 2013 Three Months Ended December 31, 2014 Expenses: Research & Development $18,882 $29,814 General & Administrative 4,465 7,397 Acquired In-process R&D -- 7,000 Total Expenses 23,347 44,211 Loss from Operations (23,347) (44,211) Interest Income/(Expense) 7 (3,724) Net Loss ($23,340) ($47,935) Loss per Share ($0.72) ($1.33) $7.0M of IPR&D in Q4 2014 includes a milestone payment related to rolapitant ($5.0M) and an upfront license payment related to expansion of our immuno-oncology programs ($2.0M) Unless otherwise noted, figures are in thousands, except for per-share data.

FY 2014 Financial Results Year Ended December 31, 2013 Year Ended December 31, 2014 Expenses: Research & Development $75,725 $118,425 General & Administrative 14,780 23,935 Acquired In-process R&D 1,940 24,900 Total Expenses 92,445 167,260 Loss from Operations (92,445) (167,260) Interest Income/(Expense) 83 (3,752) Net Loss ($92,362) ($171,012) Loss per Share ($2.93) ($4.79) As of December 31, 2014: Cash & equivalents balance totaled approximately $257 million Approximately 36.1 million shares outstanding of common stock Unless otherwise noted, figures are in thousands, except for per-share data.

Mary Lynne Hedley, Ph.D. President and COO

Development Programs Update Oral rolapitant NDA under review by FDA; PDUFA date 09/05/15 Oral rolapitant commercial launch planned for Q4 2015 A clinical trial has been initiated to compare the exposure of IV rolapitant to oral rolapitant; results expected in mid-2015 Rolapitant Expanded Phase 3 NOVA trial non-gBRCA cohort enrollment on track to complete during Q1 2015 QUADRA trial for treatment of patients with recurrent ovarian cancer to begin in Q1 2015 SCLC and 1L ovarian trials to begin in 2H 2015 Phase 3 BRAVO trial enrollment to continue through 2015 Niraparib Controlled release formulation available for use within ongoing study ALK+, ALK-inhibitor naive patients enrolling Goal to make go / no go decision for registration program by year-end 2015 TSR-011 Advancing TSR-042 antibody (anti-PD-1) to support IND filing with U.S. FDA in late 2015 Advance IND enabling studies for anti-TIM-3 and anti-LAG-3 antibody candidates Bispecific antibody candidate identification work continues I-O Platform NDA: New drug application IV: Intravenous SCLC: Small cell lung cancer

Development Programs Update NDA: New drug application IV: Intravenous SCLC: Small cell lung cancer Oral rolapitant NDA under review by FDA; PDUFA date 09/05/15 Oral rolapitant commercial launch planned for Q4 2015 A clinical trial has been initiated to compare the exposure of IV rolapitant to oral rolapitant; results expected in mid-2015 Rolapitant Expanded Phase 3 NOVA trial non-gBRCA cohort enrollment on track to complete during Q1 2015 QUADRA trial for treatment of patients with recurrent ovarian cancer to begin in Q1 2015 SCLC and 1L ovarian trials to begin in 2H 2015 Phase 3 BRAVO trial enrollment to continue through 2015 Niraparib Controlled release formulation available for use within ongoing study ALK+, ALK-inhibitor naive patients enrolling Goal to make go / no go decision for registration program by year-end 2015 TSR-011 Advancing TSR-042 antibody (anti-PD-1) to support IND filing with U.S. FDA in late 2015 Advance IND enabling studies for anti-TIM-3 and anti-LAG-3 antibody candidates Bispecific antibody candidate identification work continues I-O Platform

Niraparib Value Proposition Compelling RECIST response rate and durability in heavily pre-treated patients 1 Potentially differentiated tolerability profile 2 Convenient, once per day dosing (3 capsules) 3 Broadest PARPi program in ovarian cancer 4 Biomarker incorporation potentially allows for patient selection 5 Potential for combinations with immuno-oncology and other targeted agents 6

Niraparib Dosing: 300 mg (3x100 mg capsules) Once Daily Building an Ovarian Cancer Franchise Recurrent Ovarian Treatment QUADRA Trial ORR primary endpoint Efficacy analyses in prespecified gBRCAmut and HRD+ subgroups Phase 2 trial to begin Q1 2015 1st Line Maintenance PRIMA Trial PFS primary endpoint Will enroll gBRCAmut and HRD+ patients Phase 3 trial to begin 2H 2015 PFS: Progression free survival ORR: Overall response rate HRD: Homologous recombination deficiency

*TCGA, Integrated genomic analyses of ovarian carcinoma, Nature, 2011, 474, 609. myChoice HRDTM Selected as Tumor Marker Classifier myChoice HRD Applied to HGS-OvCa Can Separate BRCA Deficient and Other HRD Tumors from HR Proficient A Cut-Off Value of 42 Has Been Determined Based on Combined Breast and Ovarian Data Combined Studies Ovarian Likely Non-Responders Likely Responders MyChoice HRD test is a proprietary, algorithm-based genomic test to define HRD status HRD score distribution in ovarian cancer shows clear bimodality, demonstrating delineation of HR deficient and proficient tumors Myriad has regulatory experience in developing an FDA approved test Number of Samples Likely Non-Responders Likely Responders

 Prospectively defined statistical analysis of PFS in the HRD population >90% power PFS: Progression free survival; HRD: Homologous recombination deficiency Phase 3 Trial of Niraparib in 2nd Line (Recurrent) Ovarian Cancer Maintenance (NOVA Trial) gBRCAmut Endpoint Assessment Niraparib 300 mg Placebo Non-gBRCAmut / HRD Endpoint Assessment Niraparib 300 mg Placebo 2:1 Randomization 2:1 Randomization n=120 n=60 n=207 n=103 Overall survival, PFS 2, patient reported outcomes PFS; >90% power to detect 4.5 month improvement (HR 0.50 in both cohorts) Assumption: 4.5 month PFS for control arms High Grade Serous Ovarian Cancer, Platinum Sensitive, Relapsed Response to Platinum Treatment n=490

Endpoint Assessment Niraparib 300 mg Daily Treatment Received > 3 Lines of Chemotherapy N=225 Registration Trial of Niraparib for Treatment of Ovarian Cancer (QUADRA Trial) Duration of Response, Disease Control Rate, Safety Overall RECIST Response Rate High Grade Serous Ovarian Cancer, Platinum Resistant or Platinum Sensitive, gBRCAmut or HRD

Placebo N=96 2:1 Randomization *Control from ICON 7, OVAR 16 and erlotinib studies Phase 3 Trial of Niraparib in 1st Line Ovarian Cancer Maintenance (PRIMA Trial) PFS Power assumptions: 13* vs. 20 months, HR=0.625, 90% power PFS2, OS, QOL, Safety Responded to 1st Line Platinum Chemotherapy, with No Evidence of Progression, No Disease >2cm and Normal CA125 High Grade Serous Ovarian Cancer

1L: 1st Line; 2L: 2nd Line; Treatment: 3 or more lines of previous therapy Dollar figures reflect current PARP inhibitor pricing. Source: Company estimates. PARP Inhibitor Peak Market Opportunity in Ovarian Cancer Approximates $4 Billion gBRCAmut non-gBRCAmut/HRD+ Non-gBRCAmut / HRD- United States Europe Approximately 40,000 Eligible Patients in the U.S. and Europe Other/Ineligible

Breast Cancer: Phase 3 Treatment Trial Design (BRAVO Trial) 2:1 Randomization 300 mg Niraparib Investigator Choice: Eribulin, Capecitabine, Gemcitabine or Vinorelbine PFS: Progression free survival TNBC: Triple negative breast cancer PFS >95% power to detect 3 month improvement (HR 0.50) Assumption: 3 month PFS for control: weighted average of 2.3 months for TNBC and 3.9 months for others vs. 6 months for niraparib; 60% of gBRCAmut are TNBC Overall survival Up to Two Prior Treatments for Advanced/Metastatic Disease, Including Anthracycline and Taxane gBRCAmut, Advanced/Metastatic Breast Cancer (n=306)

Dollar figures reflect current PARP inhibitor pricing. Source: Company estimates PARP Inhibitor Peak Market Opportunity in gBRCAmut Breast Cancer Exceeds $1 Billion Approximately 20,000 Eligible Patients in the U.S. and Europe 1L Patients 2L Patients 3L Patients

Development Programs Update NDA: New drug application IV: Intravenous SCLC: Small cell lung cancer IND: Investigational New Drug Oral rolapitant NDA under review by FDA; PDUFA date 09/05/15 Oral rolapitant commercial launch planned for Q4 2015 A clinical trial has been initiated to compare the exposure of IV rolapitant to oral rolapitant; results expected in mid-2015 Rolapitant Expanded Phase 3 NOVA trial non-gBRCA cohort enrollment on track to complete during Q1 2015 QUADRA trial for treatment of patients with recurrent ovarian cancer to begin in Q1 2015 SCLC and 1L ovarian trials to begin in 2H 2015 Phase 3 BRAVO trial enrollment to continue through 2015 Niraparib Controlled release formulation available for use within ongoing study ALK+, ALK-inhibitor naive patients enrolling Goal to make go / no go decision for registration program by year-end 2015 TSR-011 Advancing TSR-042 antibody (anti-PD-1) to support IND filing with U.S. FDA in late 2015 Advance IND enabling studies for anti-TIM-3 and anti-LAG-3 antibody candidates Bispecific antibody candidate identification work continues I-O Platform

Development Programs Update NDA: New Drug Application IV: Intravenous SCLC: Small cell lung cancer IND: Investigational New Drug Oral rolapitant NDA under review by FDA; PDUFA date 09/05/15 Oral rolapitant commercial launch planned for Q4 2015 A clinical trial has been initiated to compare the exposure of IV rolapitant to oral rolapitant; results expected in mid-2015 Rolapitant Expanded Phase 3 NOVA trial non-gBRCA cohort enrollment on track to complete during Q1 2015 QUADRA trial for treatment of patients with recurrent ovarian cancer to begin in Q1 2015 SCLC and 1L ovarian trials to begin in 2H 2015 Phase 3 BRAVO trial enrollment to continue through 2015 Niraparib Controlled release formulation available for use within ongoing study ALK+, ALK-inhibitor naive patients enrolling Goal to make go / no go decision for registration program by year-end 2015 TSR-011 Advancing TSR-042 antibody (anti-PD-1) to support IND filing with U.S. FDA in late 2015 Advance IND enabling studies for anti-TIM-3 and anti-LAG-3 antibody candidates Bispecific antibody candidate identification work continues I-O Platform

Lonnie Moulder Chief Executive Officer

Rolapitant Value Proposition 1 Provides 5 continuous days of protection from CINV 2 Convenient single dose administered just prior to chemotherapy 3 4 5 6 Customer partnerships enable support of CINV educational initiatives Reduced risk of CYP3A4-mediated drug interactions Oral and IV formulations in development to address entire market May be combined with any approved 5-HT3 RA

Source: IMS data and Company estimates U.S. NK-1 Market Opportunity in CINV Cisplatin AC-based breast cancer regimens Certain carboplatin regimens Other Addressable Market Opportunity for NK-1 Receptor Antagonists is Approximately 5 Million Doses Annually in the U.S.

1 As reported by IMS National Sales Perspective Dollar figures reflect current NK-1 RA pricing of ~$300/cycle on average 5 Million “Day One” Doses Annually in the U.S. Significant Revenue Potential from Targeted Markets Rolapitant Potential Share: 25% 50% 75% Eligible Chemotherapy Initiations1 1M doses $300 M 2M doses $600 M 3M doses $900 M 0.25M doses $75 M 0.5M doses $150 M 0.75M doses $225 M IV Opportunity 4M Doses Oral Opportunity 1M Doses IV Oral Opportunity for Significant Leverage: Anticipate Rolapitant P&L to Break Even at Annual Sales of ~$50–60M

[LOGO]

2015: A Transformative Year for TESARO Initiate potential registration trial for treatment of patients with recurrent ovarian cancer during Q1 (QUADRA) Complete enrollment of the expanded non-gBRCA cohort of NOVA in Q1 Report the initial data from NOVA during 2015 Initiate trials in 1L ovarian cancer and SCLC in 2H 2015 Niraparib Establish a full-scale oncology U.S. commercial organization by Q3 2015 Oral rolapitant PDUFA date September 5, 2015 Submit NDA for IV rolapitant following regulatory approval of oral rolapitant Rolapitant Enroll additional ALK+, ALKi-naïve patients to enable go/no go decision Submit IND for TSR-042 by year end Selectively pursue combination approaches for I-O candidates Early Stage Pipeline NDA: New Drug Application IV: Intravenous SCLC: Small cell lung cancer IND: Investigational New Drug

Fourth-Quarter and Full-Year 2014 Results February 19, 2015