Clovis one-ups AstraZeneca with a 'breakthrough' tag for its cancer drug

Clovis Oncology ($CLVS) picked up the FDA's coveted breakthrough therapy designation for its in-development ovarian cancer treatment, securing a speedy review and notching an honor denied to rival AstraZeneca ($AZN) and its similar drug.

The drug, rucaparib, works by inhibiting enzymes called poly ADP ribose polymerases, or PARPs, getting in the way of the process that allows certain gene mutations to spread cancer throughout the body. The FDA has granted rucaparib its breakthrough tag for use against advanced ovarian cancer in patients with BRCA mutations who have failed two lines of therapy, granting Clovis access to top agency officials as it works toward a filing and guaranteeing a truncated review once it submits the drug.

AstraZeneca tried and failed to secure a breakthrough designation for its PARP inhibitor, approved as Lynparza late last year, making Clovis' treatment the first in its class to get the nod. AstraZeneca's drug won an accelerated approval on the strength of Phase II data, and its long-term fate depends on a confirmatory study already underway.

Now Clovis plans to follow a similar path, setting sights on a 2016 FDA filing based on Phase II results while enrolling a larger Phase III effort. If rucaparib is approved, AstraZeneca's drug would have a significant head start on the market, but the FDA's apparent preference for Clovis' candidate could help the company make up ground. Furthermore, Lynparza is approved as a fourth-line therapy, whereas rucaparib's breakthrough designation applies to its use as a third option for ovarian cancer. AstraZeneca is expected to unveil new data this year that could support Lynparza's full approval, but that's unlikely to affect Clovis' breakthrough tag, Leerink said in a note to investors.

Clovis believes the nod "is in recognition of the encouraging response rate observed in women with BRCA-mutated advanced ovarian cancer treated with rucaparib," CEO Patrick Mahaffy said in a statement, "and this designation reinforces the unique profile of rucaparib among PARP inhibitors, as well as our leadership in the differentiated clinical development of a PARP inhibitor."

The news sent Clovis' shares up about 10% on Tuesday morning, making for the biotech's second breakthrough nod in less than a year. Last May, the Colorado company secured a breakthrough tag for CO-1686, an EGFR blocker designed to treat a certain type of lung cancer.

- read the statement