A cancer drug sold by GlaxoSmithKline was shown in a clinical trial to extend by several months the length of time ovarian cancer patients lived without their disease worsening.

The findings suggest that the oral drug, Votrient, could be used as a "maintenance" therapy for many ovarian cancer patients whose disease had returned after initial surgery and chemotherapy.

"This is the first positive clinical trial for a targeted agent in ovarian cancer," said lead study author Dr Andreas du Bois, professor of gynecologic oncology at Kliniken Essen Mitte in Essen, Germany.

The study was presented on Saturday at the annual meeting of the American Society of Clinical Oncology in Chicago.

Votrient, designed to interfere with the growth of new blood vessels that tumors need to survive, is approved in the US to treat people with kidney cancer or soft-tissue sarcoma, a group of rare but aggressive cancers that usually begin in the muscles, fat or other tissues.

A large-scale Phase 3 trial in women with advanced ovarian cancer found that the drug, also known as pazopanib, extended the time patients lived without their disease getting worse by an average of 5.6 months, compared with a placebo treatment.

An estimated 230,000 women worldwide are diagnosed with ovarian cancer each year. Most are not diagnosed before the cancer has spread, and up to 70 per cent of them die within five years.

"Our findings show that we finally have a drug that can maintain control over ovarian cancer growth achieved through initial treatments," du Bois said. "If pazopanib is approved for ovarian cancer, many patients will experience longer disease-free and chemotherapy-free periods."

The study, which involved 940 patients who had surgery and at least five rounds of chemotherapy, found that the median time before the diseased worsened in the pazopanib and placebo groups was 17.9 months and 12.3 months, respectively.

An interim analysis found no difference in overall survival between the two groups.

Side effects seen in the trial included hypertension, diarrhea and nausea. Votrient was associated with the deaths of two trial patients.

The Glaxo drug carries a boxed warning, the most serious kind, about its potential link to liver damage, which can be fatal. Researchers said none of the patients in the ovarian cancer trial experienced liver failure, although some did have elevated liver enzymes, which were manageable. - Reuters