Tesaro, Merck To Collaborate On Combination Study Of Niraparib, Keytruda

(RTTNews) - Tesaro, Inc. (TSRO) and Merck & Co. Inc. (MRK) announced a collaboration to evaluate the combination of Tesaro's niraparib plus Merck's anti-PD1 therapy, Keytruda or pembrolizumab, in a Phase 1/2 clinical trial.

The companies said the trial is planned to evaluate the preliminary safety and efficacy of niraparib plus Keytruda in patients with triple negative breast cancer or ovarian cancer. The trial will be conducted by Tesaro and Merck, through a subsidiary, and is expected to begin by the end of 2015.

Mary Lynne Hedley, President and COO of Tesaro said, "The combination of a PARP inhibitor and anti-PD-1 antibody in this study has the potential to build upon the responses already observed with each of these compounds as monotherapies. Treatment options for patients with triple negative breast cancer are extremely limited, and we look forward to assessing this exciting new approach."

Niraparib is an oral, selective inhibitor of PARP-1 and PARP-2. PARP, or poly (ADP-ribose) polymerase, is a DNA repair protein that restores single strand DNA breaks.

Keytruda or pembrolizumab is a humanized monoclonal antibody that blocks the interaction between PD-1 and its ligands, PD-L1 and PD-L2. By binding to the PD-1 receptor and blocking the interaction with the receptor ligands, KEYTRUDA releases the PD-1 pathway-mediated inhibition of the immune response, including the anti-tumor immune response.