The Parp retreat begins
Anyone wondering about the quiet cancellation of a US advisory panel investigating the Parp inhibitor Zejula in second-line ovarian cancer maintenance found out the reason today. The FDA has asked GSK to restrict this use to Brca-positive patients without an adcom’s input, and today GSK complied. The adcom was to have analysed the Nova study, whose PFS benefit backed an all-comers indication. The anomaly was that emerging data suggested a benefit only in Brca-positives, and today GSK confirmed that non-gBrca patients given Zejula in Nova generated a 1.06 hazard ratio for overall survival, meaning that numerically they were at increased risk of death versus control. With yet another crack appearing in GSK’s oncology strategy the stock fell 4% this morning. The new restriction does not apply to Zejula’s first-line maintenance use – also backed by a PFS all-comers benefit – or to Astrazeneca’s Parp Lynparza, which carries an all-comers second-line maintenance label on the strength of two studies that did show an OS benefit. What is for now a minor change could signal the start of a pullback: Lynparza yesterday missed consensus sales estimates, something SVB analysts put down to growing concerns about ovarian cancer use beyond Brca-positive disease.