Niraparib delivered the desired result when given as monotherapy in the patient population, irrespective of biomarker status.
The results of the PRIMA trial were presented at the 2019 European Society for Medical Oncology congress and published simultaneously in The New England Journal of Medicine.
The late-stage trial is a randomised, double-blind, placebo-controlled study of the PARP inhibitor as a maintenance therapy in first-line Stage III or IV ovarian cancer patients who responded to platinum-based chemotherapy.
Treatment with niraparib led to a reduction by 38% in the risk of disease progression or death in the overall population, said GSK.
GSK Chief Scientific Officer and R&D president Hal Barron said: “Ovarian cancer is the eighth most commonly occurring cancer in women worldwide and women with this devastating disease have a five-year survival rate of less than 50%. PRIMA is a landmark study as we believe these data have the potential to fundamentally change how women with ovarian cancer are treated.”
The pharma major said that the PARP inhibitor also showed a promising trend toward improvement in overall survival (OS) compared to placebo during an interim analysis of the parameter.
GSK said that the pre-planned interim analysis of OS statically favoured the GSK cancer drug in the overall population. The safety profile of the drug observed in the phase 3 trial was on par with its established profile.
Clinica Universidad de Navarr medical oncology department co-director Antonio Gonzalez, who was the primary investigator for the PRIMA trial, said: “The PRIMA study demonstrated the importance of maintenance therapy and the benefit that niraparib provided to women with ovarian cancer. I believe that niraparib monotherapy after surgery and platinum-based chemotherapy could be an important new treatment option for patients.”
In March 2017, the PARP inhibitor was approved by the US Food and Drug Administration (FDA) for the treatment of women having recurrent ovarian cancer. The approval was given to US oncology-focused company Tesaro, which was acquired by GSK for £4bn earlier this year.
Niraparib also secured approval in Europe as a treatment for adult women having recurrent ovarian cancer who are responsive to platinum-based chemotherapy, regardless of BRCA mutation or biomarker status.