AstraZeneca (NASDAQ:AZN) and Merck's (NYSE:MRK) drug Lynparza was approved for use as maintenance therapy in BRCA-positive, advanced ovarian cancer patients in 2018; on Friday, the healthcare companies unveiled long-term trial data that could increase its use in those patients.

Specifically, five-year follow-up data from a trial evaluating Lynparza in patients with mutations to their BRCA gene who also responded to platinum-based therapy showed that the drug reduces the risk of disease progression by 67% compared to placebo.

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IMAGE SOURCE: GETTY IMAGES.

Although patients enrolled in the Solo-1 trial were given Lynparza for just two years, median progression-free survival (PFS) in those patients reached 56 months. In patients receiving a placebo, median PFS was only 13.8 months

The FDA's label expansion for Lynparza to include its use as maintenance therapy in advanced ovarian cancer was based on three-year data showing 60% of patients receiving it were progression-free at three years, compared to 27% of patients taking a placebo. At the five-year mark, 48.3% of Lynparza patients were still free from disease progression versus 20.5% in the placebo arm.

The updated results could help boost Lynparza's competitiveness with similar drugs, including GlaxoSmithKline's (NYSE:GSK) Zejula. In April, the FDA approved Zejula for maintenance use by advanced ovarian cancer patients following platinum-based therapy, regardless of BRCA mutation status.

Sales of Lynparza, which is also approved for use in amenable patients with metastatic breast cancer, pancreatic cancer, and prostate cancer, were $816 million through the first six months of 2020, up 57% year over year.