FDA Approves GSK's PARP Inhibitor Zejula for New Ovarian Cancer Indication

Ovarian Cancer

Zejula, GlaxoSmithKlines once-daily PARP inhibitor, won regulatory approval as a monotherapy maintenance treatment for women with advanced ovarian cancer whose disease is responsive to first-line platinum-based chemotherapy, regardless of biomarker status.

On Wednesday, the U.S. Food and Drug Administration (FDA) approved Zejula (niraparib) for this new indication under the agency’s Real-Time Oncology Review pilot program. Until the approval, GSK said less than 20% of women with BRCA mutant ovarian cancer were eligible to be treated with a PARP inhibitor as monotherapy in the first-line maintenance setting. Now, with the FDA’s approval, patients have more options. Zejula is now the only once-daily, oral PARP inhibitor approved in the U.S. for women with ovarian cancer beyond those with a BRCA mutation as first-line and recurrent monotherapy maintenance and later-line primary treatment settings, GSK said in its announcement.

“Women with advanced ovarian cancer have a five-year survival rate of less than 50%. This expanded indication means that many more women with this devastating disease can receive earlier treatment with Zejula, which can extend the time it takes for their cancer to progress,” GSK’s head of R&D and Chief Scientific Officer Hal Bannon said in a statement.

The sNDA was supported by data from the PRIMA study that demonstrated clinically-meaningful outcomes of Zejula treatment in the first-line maintenance setting. The study included patients who responded to first-line treatment with platinum-based chemotherapy, including those at higher risk of disease progression, a population previously under-represented in first-line ovarian cancer studies, GSK noted. In that study, Zejula met its primary endpoint of a statistically significant improvement in progression-free survival for women regardless of their biomarker status. Treatment with Zejula resulted in a 38% reduction in the risk of disease progression or death in the overall study population when compared to placebo. In the homologous recombination deficient (HRd) population of the study, treatment with Zejula resulted in a 57% reduction in the risk of disease progression or death vs. placebo

Zejula is an oral, once-daily PARP inhibitor used as maintenance treatment for ovarian cancer that secured approval from the FDA in 2017. Zejula was the first PARP inhibitor to be approved by the FDA that does not require BRCA mutation or other biomarker testing. The drug was the centerpiece of GSK’s 2018 $5.1 billion acquisition of Waltham. Mass.-based Tesaro Oncology.

Ovarian cancer is the fifth leading cause of cancer-related deaths in the United States. It is estimated that this year there will be more than 22,000 women in the U.S. diagnosed with the disease and about 14,000 disease-related deaths. While there are high response rates to platinum-based chemotherapy in the second-line advanced treatment setting, GSK noted that approximately 85% of patients will experience recurrence within two years. With each recurrence, the time a woman may spend without her cancer progressing until the next recurrence gets shorter, the company added.

“PARP inhibitors represent a major advancement in the fight against ovarian cancer, and having a new first-line maintenance option for platinum-responsive advanced ovarian cancer patients — regardless of BRCA mutation status — is especially exciting,” Audra Moran, head of Ovarian Cancer Research Alliance said in a statement.

PARP inhibitors are becoming more important in the treatment of some cancers. A study conducted by UT Southwestern has shown that PARP inhibitors could have broader effectiveness in treating other types of cancer, including ovarian and prostate cancer.

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