Tesaro’s PARP accepted for review in EU as AZ makes case for Lynparza

Tesaro hopes to be earning from its PARP in Europe from next year

Former Fierce 15 winner Tesaro ($TSRO) has taken another step toward seeing its experimental PARP med niraparib gain its first approval after the EMA accepted its ovarian cancer drug for review--as AstraZeneca ($AZN) pumps out the data to shore up its defenses against the newcomer.

Tesaro, increasingly at the center of M&A speculation since it posted some strong data for its drug back in the summer, said in a brief update that its PARP inhibitor has been accepted for review by the EMA, specifically for the maintenance treatment of patients with platinum-sensitive, recurrent ovarian cancer who are in response to platinum-based chemotherapy.

Maintenance therapy is for those women who have had prior treatment but are expected to see their cancer return. Its purpose is to avoid or slow a recurrence if the cancer is in complete remission after initial treatment.

The biotech, which also has a rolling NDA submission with the FDA, is hopeful of a 2017 European approval. Back in June, Tesaro jumped 108% on the day it published Phase III data helped increase progression-free survival (PFS) rates significantly across a series of ovarian cancer patients with different forms of the disease.

A PARP is already on the market for ovarian cancer in the form of AstraZeneca’s Lynparza (olaparib), which has a second-line setting and is expected to reach $2 billion in peak sales.

AstraZeneca is not happy about Tesaro looking to get onto the market, and earlier this week posted its own set of top-line data showing its marketed med “substantially exceeded” the PFS shown in the mid-stage trial that won originally won its approval.

The FDA based its approval of Astra’s med on a Phase II study comparing Lynparza with a placebo in BRCA-positive patients who'd relapsed after three rounds of chemotherapy.

In the 137-patient study, the drug chalked up a 34% response rate, with half of patients responding for at least 7.9 months. The drug was approved alongside a companion diagnostic, BRACAnalysis CDx, from Myriad Genetics.

Both will also need to contend with Medivation ($MDVN), recently snapped up for $14 billion by Pfizer ($PFE), which has its own PARP in late-stage testing. Its med talazoparib was originally licensed from BioMarin ($BMRN) last year. Tesaro got its hands on niraparib from Merck ($MRK) 4 years ago.

The biotech, which has a market cap just shy of $6 billion, was slightly down yesterday by 0.7%, but since its PARP data were released in June its shares have skyrocketed from around $37 a share to $118 apiece at end of play last night.