Tesaro Inc (NASDAQ:TSRO) said its ovarian cancer drug candidate niraparib significantly improved progression-free survival (PFS) in four patient groups in a Phase 3 trial. The outcome of the study suggests that niraparib could treat 70% of all ovarian cancer patients. The results of the study also showed niraparib could be the drug to beat in the PARP inhibitor category.
Of the four subsets of ovarian patients who received niraparib treatment, the group with BRCA gene mutation had the highest median PFS rate. The group’s PFS was 15.5 months better than the placebo group. The performance of niraparib in the Phase 3 study show the drug could benefit 70% of ovarian cancer patients.
“An oral maintenance treatment that could lengthen the PFS interval between rounds of platinum-based chemotherapy would be very meaningful for patients with ovarian cancer, who often live with a fear of recurrence after ending active treatment,” said Dr. Mansoor Raza Mirza, the principal investigator in TSRO’s Phase 3 study of niraparib.
Tolerability of the treatment
Niraparib was also well tolerated in all the groups. Only less than 15% of the patients dropped out of the Phase 3 study because of adverse effects. Dosing changes helped resolve the adverse effects in patients with grade 3 or 4 adverse events.
Filing for approval
Filing of new drug application for niraparib has been on installment basis, better known a rolling application. Tesaro expects to complete the rolling application this quarter and if everything goes well the drug should be ready to enter market by next year.
Near-term competition appears limited
Tesaro is not alone in the PARP inhibitor market, but there seems to be serious near-term competition threat to niraparib. While niraparib has demonstrated that it could treat 70% of all ovarian cancer patients, AstraZeneca plc (ADR) (NYSE:AZN)’s PARP inhibitor known as Lynparza was only granted conditional approval in 2014. Clovis Oncology Inc (NASDAQ:CLVS), which is also working a PARP inhibitor, was recently rattled after preliminary data showed that its drug for ovarian cancer could be inferior to Lynparza by AZN.
Tesaro stock rallied 18.79% to $117.91 in the last session.
