CancerConnect News: The US Food and Drug Administration (FDA) has extended the approval of Lynparza (olaparib) to include the treatment of metastatic breast cancer in patients who carry the specific inherited BRCA mutation. These patients can be identified by using the FDA-approved genetic test, BRACAnalysis CDx (Myriad Genetic Laboratories).
About BRCA Breast Cancer
Breast cancer is the most common type of cancer in women, with some 250,000 cases likely to be diagnosed in the U.S. this year About 3 percent of breast cancers are in people who inherited BRCA mutations. Mutations in the BRCA gene raise the risk of cancer because they make the body less likely to repair damage to its DNA, making the mutations that lead to cancer more likely. There has been a trend in recent years that these women opt for double mastectomies in order to lower their cancer risk.
LynparzaTM is a poly ADP-ribose polymerase (PARP) inhibitor that blocks enzymes involved in repairing damaged DNA. It was initially approved for women with heavily pretreated ovarian cancer that is associated with defective BRCA genes. By disrupting cancer cells’ ability to repair themselves, PARP inhibitors slow uncontrolled growth and replication of cancer cells.
The FDA notes that the safety and efficacy of Lynparza in the treatment of breast cancer were determined on the basis of findings from the OlympyiAD trial, a randomized clinical trial of 302 patients with HER2-negative metastatic breast cancer with a germline BRCA mutation. In the OlympyiAD clinical study of 302 women whose breast cancer had spread, Lynparza reduced the risk of cancer growing by 42% compared to treatment with chemotherapy. Overall 60% of the patients who received Lynparza experienced a response compared to only 29% of those treated with chemotherapy. The time to cancer progression was delayed almost twice as long for Lynparza treated patients compared to those receiving chemotherapy.
This is the first comparative clinical trial in breast cancer that shows PARP inhibitors are superior to chemotherapy for HER2-negative metastatic breast cancer patients who have a BRCA mutation.
Reference: Robson M., Im SA., Senkus E., et al, OlympiAD: Phase III trial of olaparib monotherapy versus chemotherapy for patients (pts) with HER2-negative metastatic breast cancer (mBC) and a germline BRCA mutation (gBRCAm), Presented at the American Society of Clinical Oncology Annual Meeting, Chicago; June 2-6, 2017.