Tesaro bags priority review, June PDUFA date for PARP inhibitor

The FDA has granted priority review status to Tesaro’s PARP inhibitor niraparib. The regulatory status sets Tesaro up to secure approval for niraparib in ovarian cancer by June 30 without going through an advisory committee meeting.

Tesaro wrapped up the rolling NDA for niraparib at the start of last month. Since then, FDA has ruled the filing is eligible for priority review and, as it stands, will be assessed without the input of an advisory committee panel. FDA could shift its position on the need for an advisory committee, but for now the path to a regulatory nod in the first half of next year looks clear.

Niraparib has secured the favorable regulatory status on the strength of data generated in a phase 3 study. Participants in the niraparib arm of the 553-person, double-blind, placebo-controlled study had an average progression-free survival (PFS) of 21 months, compared to 5.5 months for the control arm. The difference in PFS shrunk in nongermline BRCA mutant patients—9.3 months for niraparib versus 3.9 months for the control—but was still large enough to be statistically significant.

Importantly, the performance in nongermline BRCA mutant patients positions niraparib for use in a broader population than other PARP inhibitors, including Clovis’ recently approved Rubraca. Tesaro also stands to get a label that allows niraparib to be prescribed earlier in the treatment pathway than Rubraca. Clovis expects to have data from a phase 3 trial of Rubraca as a second-line maintenance therapy by the middle of next year, but by then Tesaro could already have won approval for niraparib in the indication.

The second-line maintenance therapy market represents a big opportunity for Tesaro and its rivals, a fact reflected in the more than 200% rise in the PARP player’s share price since it posted data on niraparib in the indication in June. Tesaro confirmed its status as a front runner in the race to deliver a drug that enables patients to stay cancer-free when it posted more data in October. Those results are now with FDA for review in the NDA.