Clovis' PARP inhibitor rucaparib will get a speedy review from US regulators as a treatment for patients with certain forms of advanced ovarian cancer.

The US Food and Drug Administration has agreed to undertake a priority review of the drug for patients with deleterious BRCA-mutated tumours inclusive of both germline and somatic BRCA mutations, and who have been treated with two or more chemotherapies.

"There is tremendous need for additional therapeutic options for patients with advanced mutant BRCA ovarian cancer and we look forward to cooperating with FDA on the rucaparib NDA review," noted Patrick Mahaffy, president and chief executive of Clovis.

The submission contains efficacy data from two multicenter, single-arm, open-label clinical trials, Study 1 (Study 10, NCT01482715), involving just platinum sensitive patients, and Study 2 (ARIEL2 Parts 1 and 2, NCT01891344), which concluded platinum sensitive, platinum resistant and platinum refractory patients.

Overall, the objective response rate was found to be 54 percent, with nine percent of patients experiencing a complete response. Median duration of response was across both studies was 9.2 months.

On the safety side, the Grade 3/4 treatment emergent adverse events (AEs) reported in 10 percent of patients or more were anaemia/decreased or low hemoglobin (25 percent), fatigue/asthenia (11 percent) and increased ALT/AST (11 percent). Increases in aspartate and alanine aminotransferase levels observed were "asymptomatic, reversible and were rarely associated with increases in bilirubin," the firm noted, adding that the elevations normalised over time with continued rucaparib treatment.

"Recurrent ovarian cancer remains a very difficult disease to treat, even among women who carry, or whose tumours have a mutation in the BRCA genes. Despite the available treatment options, few effective therapies are at our disposal. Thus, the opportunity to treat women with germline or somatic BRCA mutations with rucaparib after two prior lines of platinum-based therapy, represents a meaningful step forward for our patients," added principal ARIEL trial investigator Robert Coleman, professor and deputy chairman, Clinical Research, Ann Rife Cox Chair in Gynecology, Department of Gynecologic Oncology and Reproductive Medicine at University of Texas MD Anderson Cancer Center.

The drug was assigned breakthrough status in the US last year, potentially accelerating its development timeline, and could be filed with EU regulators in the fourth quarter.