A phase III clinical trial in women with advanced ovarian cancer finds that treatment with the oral targeted drug pazopanib following initial successful chemotherapy extends disease-free survival by an average of 5.6 months, compared to placebo.

Advanced ovarian cancer is an aggressive disease with a cure rate of only 20-25 percent.

Despite successful initial treatment with surgery and chemotherapy, about 70 percent of patients with advanced ovarian cancer experience a relapse, half in the first year.

Upon relapse, patients have to resume aggressive treatments.

At this time, there is no test available to predict a patient’s risk for relapse, so a maintenance therapy such as this one would be used for most patients.

“Our findings show that we finally have a drug that can maintain control over ovarian cancer growth achieved through initial treatments,” said lead author Andreas du Bois, MD, a professor of gynecologic oncology at Kliniken Essen Mitte in Essen, Germany. “If pazopanib is approved for ovarian cancer, many patients will experience longer disease-free and chemotherapy-free periods. During this time, the patient keeps control over the disease instead of the disease having control over patient’s life.”

Pazopanib is an oral drug that blocks several targets involved in the growth of tumours and their blood vessels (angiogenesis). In the study, 940 patients with stage III/IV ovarian, fallopian tube, and primary peritoneal cancer were randomly assigned to receive pazopanib or placebo daily for 24 months. All patients had prior surgery and five or more rounds of chemotherapy that successfully prevented the disease from worsening. Patients were followed for 24 months, on average. The median time to disease worsening (progression-free survival) in the pazopanib and placebo group was 17.9 and 12.3 months, respectively.

“Relapses remain all too common for women with advanced ovarian cancer. This large trial shows us that targeting multiple molecular cancer drivers can have a substantial impact on this cancer’s ability to grow, giving our patients significantly longer time before relapse. This study offers a real-world example of how the precision medicine era of cancer research is paying off in areas where no alternate approved drugs exist,” said Carol Aghajanian, MD, ASCO spokesperson and gynecologic cancers expert.

Pazopanib is already approved by the FDA for treatment of kidney cancer and soft tissue sarcoma. No maintenance therapies are currently approved for ovarian cancer in the United States though bevacizumab is registered for use concurrently with chemotherapy and subsequently as maintenance therapy in Europe based on a clinical trial reporting extension of progression-free survival.

Ovarian cancer is the fifth leading cause of cancer death among women in developed countries. An immediate goal for this research is to combine pazopanib with other targeted drugs and personalize therapy according to patient and tumour characteristics.

Source: ASCO