Clovis Oncology's Rubraca data sets stage for label expansion

[June 19, 2017] By Natalie Grover

(Reuters) - Positive data on Clovis Oncology Inc's ovarian cancer drug, Rubraca, from a late-stage study could help the U.S. biotech widen the use of the therapy and differentiate it against rivals, the company said on Monday.

Rubraca was granted accelerated approval last December by the U.S. Food and Drug Administration in patients whose cancer tested positive for defective BRCA genes, and whose disease had advanced despite two or more rounds of chemotherapy.

Rubraca, like Tesaro Inc's niraparib and AstraZeneca Plc's lynparza, belongs to a closely watched class of new medicines called PARP inhibitors, which block enzymes involved in repairing damaged DNA, thereby helping to kill cancer cells.

The latest clinical trial was designed to move Rubraca up to second-line and maintenance therapy, where it would be used for longer periods, and broaden its use in patients regardless of gene mutations.

Maintenance therapy immediately follows initial treatment to keep patients cancer-free if they go into remission.

The 564-patient trial, called ARIEL3, tested Rubraca against a placebo in patients with various gene mutations who had undergone initial platinum-based chemotherapy.

Women with recurrent ovarian cancer lived a median 10.8 months without their disease worsening when given Rubraca, against 5.4 months for those on placebo, based assessments carried out by investigators.

When disease progression was measured by a central, blinded review, however, the figure rose to 13.7 months, the company said.

Overall, Rubraca slowed recurrence in patients who were in remission, and shrunk tumors in those who entered the trial with residual disease, in some cases even eliminating them.

Based on these findings, Clovis plans to submit a U.S. application within the next four months to expand Rubraca's label for the second-line and later for the maintenance treatment indication.

If approved, the drug could be used in the maintenance setting if the patient goes into remission following chemotherapy, or be used as a treatment if the patient prefers to wait until there's real evidence that the tumor has recurred, Chief Executive Patrick Mahaffy told Reuters.

More than 22,400 American women will be diagnosed with ovarian cancer this year, according to the American Cancer Society.

About 25 percent of those diagnosed will carry BRCA mutations, Mahaffy said, adding that with an expanded label, Rubraca's addressable population would effectively quadruple.

(Reporting by Natalie Grover in Bengaluru; Editing by Amrutha Gayathri)

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