GSK's sNDA for Ovarian Cancer Drug Zejula Accepted by FDA

NEW YORK – GlaxoSmithKline said Monday that the supplemental new drug application for niraparib (Zejula) as a first-line maintenance treatment for chemotherapy-responsive advanced ovarian cancer was accepted by the US Food and Drug Administration.

GSK is seeking approval for the drug in an all-comer patient population, regardless of whether they have tumors that are homologous recombination deficient (HRD). HRD is defined by either a deleterious or suspected deleterious BRCA mutation, or genomic instability in patients with disease progression greater than six months after response to the last platinum-based chemotherapy.

Myriad Genetics also recently announced that it is pursuing approval of its HRD test, MyChoice CDx, for patients likely to respond to niraparib in this setting. The test was used to evaluate the efficacy of niraparib in this subset of patients in the Phase III PRIMA study, which showed that those with HRD saw a greater magnitude of benefit from the PARP inhibitor than those without this genomic instability in their tumors. 

Data from this study, published in the New England Journal of Medicine, also formed the basis of GSK's present supplemental NDA for niraparib. The study showed that newly diagnosed advanced ovarian cancer patients had longer median progression-free survival on niraparib compared to placebo (13.8 months versus 8.2 months), regardless of their biomarker status.

Based on this, GSK CEO Emma Walmsley said at the JP Morgan Healthcare Conference earlier this year that "since Zejula demonstrated a benefit in all patients, we anticipate that doctors will be able to start patients on therapy without any need for HRD testing."

Meanwhile, Myriad is continuing to push for FDA approval of MyChoice CDx in new drug indications. Last October, the FDA approved niraparib as a fourth- or later-line treatment of advanced ovarian, fallopian tube, or primary peritoneal cancer with homologous recombination deficiency, and simultaneously approved Myriad's test to identify best responders to treatment.