USFDA approval of Lynparza to Treat BRCA-mutated Metastatic Breast Cancer

The U.S. Food and Drug Administration (FDA) has approved Lynparza (olaparib) for a difficult-to-treat form of metastatic breast cancer.

Patients with BRCA-mutated, HER2-negative breast cancer who have previously been treated with chemotherapy are now approved to be treated with Lynparza.

The FDA’s approval is based on data showing that Lynparza — developed by AstraZeneca working together with Merck (known as MSD outside the U.S. and Canada) — prolonged the time patients lived without their cancer progressing, compared to standard-of-care chemotherapy.

Lynparza was initially approved by the FDA for the treatment of BRCA-mutated advanced ovarian cancer in December 2014. In August 2017, the regulatory agency extended its approval to include the maintenance treatment of recurrent ovarian, fallopian tube, or primary peritoneal cancer.

Lynparza is a PARP inhibitor, which acts to block DNA repair processes. The PARP enzyme is particularly important for DNA repair in people with BRCA mutations, and blocking it prevents the survival of tumors.

Clinical Trial Strategies

• The approval rests on data from the Phase 3 OlympiAD trial (NCT02000622), which compared Lynparza to chemotherapies Xeloda (capecitabine), Navelbine (vinorelbine), and Halaven (eribulin).
• Patients included in the trial were either triple negative — meaning that in addition to a lack of HER2, their cancer did not produce estrogen receptors (ER) or progesterone receptors (PR) — or were positive for hormone receptor (HR).
• All patients were previously treated with chemotherapy. HR-positive patients had received at least one course of hormonal treatment or were ineligible for such treatment.
• Data showed that among the 205 patients treated with Lynparza, the therapy reduced the risk of disease progression or death by 42 percent compared to chemotherapy. Lynparza also triggered a response in more patients than chemo — 52 percent responded to the treatment, compared to only 23 percent in the chemotherapy group.
• Among those who responded, 7.8 percent had a complete eradication of their cancer. However, such a complete remission was seen in only 1.5 percent of patients treated with chemotherapy.