AstraZeneca and Merck & Co. Inc. announced that the US Food and Drug Administration (FDA) has approved Lynparza (olaparib), for use in patients with deleterious or suspected deleterious germline BRCA-mutated (gBRCAm), human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer who have been previously treated with chemotherapy in the neoadjuvant, adjuvant or metastatic setting. Patients with hormone receptor positive (HR+) breast cancer should have been treated with a prior endocrine therapy or be considered inappropriate for endocrine therapy.

Patients are selected for therapy based on an FDA-approved companion diagnostic from Myriad Genetics. The approval was based on data from the randomised, open-label, Phase III OlympiAD trial which investigated Lynparza versus physician's choice of chemotherapy (capecitabine, eribulin, or vinorelbine). In the trial, Lynparza significantly prolonged progression-free survival (PFS) compared with chemotherapy, and reduced the risk of disease progression or death by 42% (HR 0.58; 95% CI 0.43-0.80; P=0.0009 median 7.0 vs 4.2 months).

Patients with measurable disease taking Lynparza (n=167) experienced an objective response rate of 52% (95% CI 44- 60), double the response rate for those in the chemotherapy arm (n=66) which was 23% (95% CI 13-35). Additionally, patients experienced a confirmed complete response rate of 7.8% for Lynparza compared to 1.5% for the chemotherapy arm.