Biopharmaceutical company AstraZeneca and Merck (NYSE:MRK) on Monday jointly announced the receipt of approval from Japan's Pharmaceuticals and Medical Devices Agency (PMDA) for LYNPARZA (olaparib) tablets in 300 mg twice daily for the treatment of breast cancer, the fifth leading cause of death among women in Japan.

The companies added that LYNPARZA (olaparib) tablets is indicated in patients with unresectable or recurrent BRCA-mutated (BRCAm), human epidermal growth factor receptor 2 (HER2)-negative breast cancer who have received prior chemotherapy. The approval is based on data from the OlympiAD trial.

OlympiAD was a randomised, open-label, multi-centre Phase 3 trial assessing the efficacy and safety of LYNPARZA tablets (300 mg twice daily) compared to physician's choice of chemotherapy (capecitabine, eribulin, or vinorelbine) in 302 patients with human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer with germline BRCA1 (gBRCA1) or BRCA2 (gBRCA2) mutations, said the company.

This international trial was conducted in 19 countries across Europe, Asia, North America and South America. The primary endpoint of the trial was progression-free survival (PFS) as measured by a Blinded Independent Central Review, according to the company.

LYNPARZA is the first-in-class PARP inhibitor and the first targeted treatment to potentially exploit DNA damage response (DDR) pathway deficiencies, such as BRCA mutations, to preferentially kill cancer cells. BRCA1 and BRCA2 are human genes that produce proteins responsible for repairing damaged DNA and play an important role in maintaining the genetic stability of cells. When either of these genes is mutated, or altered, the DNA damage may not be repaired properly and cells become unstable. As a result, cells are more likely to develop additional genetic alterations that can lead to cancer, concluded the company.