CHICAGO and BRUSSELS, Belgium, June 3, 2013 (GLOBE NEWSWIRE) -- TESARO, Inc. (Nasdaq:TSRO), an oncology-focused biopharmaceutical company, Breast International Group (BIG), a non-profit organization for academic breast cancer research groups from around the world, and the European Organization for Research and Treatment of Cancer (EORTC), an international, independent, multidisciplinary non-profit research organization, today announced a partnership for the Phase 3 clinical development of niraparib, an orally active, potent poly (ADP-ribose) polymerase (PARP) inhibitor. TESARO, BIG and EORTC will utilize BIG's and EORTC's scientific and clinical expertise and network of collaborative groups and their associated hospitals and oncology research centers around the world to accelerate completion of the Phase 3 clinical trial of niraparib in patients with breast cancer. This collaboration enables BIG and member group EORTC as well as TESARO to involve key opinion leaders to optimize the clinical study design, data analyses and publication planning. "As a leading international network of academic research groups, we look forward to partnering with TESARO to advance this potential new therapy for patients with breast cancer," said Dr. Martine Piccart, Chair of BIG. "We are very interested in evaluating the potential for niraparib to prolong progression free survival in comparison to commonly used chemotherapy treatments in patients with germline BRCA mutations, and believe that such an advance could be very meaningful for patients." "We are pleased to be collaborating with the clinical and scientific experts at BIG and EORTC to optimize the niraparib clinical study design and accelerate the international site enrollment and development of niraparib," said Mary Lynne Hedley, Ph.D., President of TESARO. "We look forward to opening this study to patients during the second half of 2013." This global Phase 3 trial of niraparib which will be conducted in partnership with BIG and the EORTC at the European study sites is planned to enroll approximately 300 patients with advanced or metastatic, germline BRCA-positive breast cancer who have been previously treated with an anthracycline and a taxane. Patients will be randomized 2:1 to receive 300 milligrams of niraparib once daily or investigator's choice of eribulin, capecitabine, gemcitabine or vinorelbine until progression. The primary endpoint of this trial is progression free survival (PFS); overall survival (OS) is a secondary endpoint.