Clovis's ovarian cancer drug set for label expansion, shares soar

Positive late-stage data on Clovis Oncology Inc's ovarian cancer drug, Rubraca, could help widen the use of the therapy and differentiate it from rivals, the U.S. biotech said on Monday, sending its shares soaring 48 percent.

The drug, like Tesaro Inc's Zejula and AstraZeneca Plc's Lynparza, belongs to a closely watched class of new medicines called PARP inhibitors, which blocks enzymes that repair damaged DNA, helping kill cancer cells in the process.

Tesaro's shares fell about 16.8 percent to $120 in trading before the bell on Monday.

Rubraca was granted accelerated approval in 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.

Clovis's trial was designed to move Rubraca up to a second-line and later maintenance treatment, where it could 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 study 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, compared with 5.4 months for those on placebo, based on assessments by investigators.

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

Clovis plans to submit a U.S. application within the next four months to expand Rubraca's label.

If approved, the drug could be used in the maintenance setting, or be used as a treatment if the patient prefers to wait for real evidence that the tumor has recurred, Clovis Chief Executive Patrick Mahaffy said.

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 could effectively quadruple.

Separately on Monday, Clovis also said it settled a class action lawsuit related to allegations of misleading investors on the potential of its experimental lung cancer drug. The company said it would take a charge of $142 million in the second quarter.