TESARO Announces Acceptance for Review of Niraparib Marketing Authorization Application by EMA

"TESARO is committed to improving the lives of patients with cancer by responsible development and commercialization, and the validation of the niraparib MAA represents a significant milestone for the Company," said Mary Lynne Hedley, Ph.D., President and COO of TESARO. "We believe niraparib could become an important new treatment option for patients. We look forward to working with the EMA during the review process and expect to complete our rolling NDA submission to the FDA for niraparib imminently."

The niraparib MAA is supported by data from the ENGOT-OV16/NOVA trial, which is a double-blind, placebo-controlled, international Phase 3 study of niraparib that enrolled 553 patients with recurrent ovarian cancer who were in a response to their most recent platinum-based chemotherapy. The full results of the NOVA trial were presented in detail at the European Society for Medical Oncology (ESMO) 2016 Congress in Copenhagen on October 8, 2016 and were published at the same time in The New England Journal of Medicine.

"The validation of our MAA for niraparib today marks an important step towards globalizing our mission of providing transformative therapies to people bravely facing cancer," said Orlando Oliveira, Senior Vice President and General Manager of Tesaro International. "With the MAA for oral rolapitant already under review by the EMA, we are well positioned for two potential product launches in Europe in 2017."

About Niraparib
Niraparib is an oral, once-daily PARP inhibitor that is currently being evaluated in four ongoing pivotal trials. TESARO is building a robust niraparib franchise by assessing activity across multiple tumor types and by evaluating several potential combinations of niraparib with other therapeutics. The ongoing development program for niraparib includes a Phase 3 trial in patients with platinum-sensitive, recurrent ovarian cancer (the NOVA trial); a Phase 3 trial in patients with first-line ovarian cancer (the PRIMA trial); a registrational Phase 2 treatment trial in patients with ovarian cancer (the QUADRA trial); and a Phase 3 trial for the treatment of patients with BRCA-positive breast cancer (the BRAVO trial). Several combination studies are also underway, including trials of niraparib plus pembrolizumab and niraparib plus bevacizumab. Janssen Biotech has licensed rights to develop and commercialize niraparib specifically for patients with prostate cancer worldwide, except in Japan.

Niraparib is an investigational agent and, as such, has not been approved by the U.S. Food and Drug Administration, EMA, or any other regulatory agencies.

About Ovarian Cancer
Approximately 22,000 women are diagnosed each year with ovarian cancer in the United States, and more than 65,000 women are diagnosed annually in Europe. Ovarian cancer is the fifth most frequent cause of cancer death among women. Despite high response rates to platinum-based chemotherapy in the second-line advanced treatment setting, approximately 85% of patients will experience recurrence within two years. If approved, niraparib may address the difficult "watchful waiting" periods experienced by patients with recurrent ovarian cancer in between cycles of platinum-based chemotherapy.

About TESARO

TESARO is an oncology-focused biopharmaceutical company devoted to providing transformative therapies to people bravely facing cancer. For more information, visit www.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 expectation to launch two products in Europe in 2017. 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, risks related to our intellectual property, the uncertainties inherent in the execution and completion of clinical trials, uncertainties surrounding the timing of availability of data from our clinical trials, risks regarding ongoing discussions with and actions by regulatory authorities, patient accrual rates for clinical trials, risks from competitors, and other matters that could affect the timing of availability of data from or initiation of our clinical trials, uncertainties regarding regulatory approvals, uncertainties regarding certain expenditures, risks related to manufacturing and supply, 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, 2015 and its Quarterly Report on Form 10-Q for the quarter ended June 30, 2016.

Investor/Media Contact:

Jennifer Davis
Sr. Director, Corporate Development & Investor Relations
+1.781.325.1116 or jdavis@tesarobio.com