An investigational drug that combats ovarian cancer by inhibiting the formation of new blood vessels has shown promise in a phase II trial, according to a presentation at the 33rd Congress of the European Society for Medical Oncology (ESMO) in Stockholm.
Prof. Michael Friedlander from Australia presented the results of an international collaborative trial which administered the drug to 35 patients with recurrent ovarian, fallopian tube or peritoneal carcinoma. At the ESMO Congress, he presented final results of the trial on behalf of his co-investigators.
Women who had already been treated with one or two previous chemotherapy regimens were eligible for the study provided they only had an elevated CA-125 or small tumors on scans. Each participant received 800mg of the oral drug daily, and the primary outcome measure was a decrease in blood levels of the protein CA-125.
CA-125 is a biological marker used to predict tumor recurrence and response to chemotherapy. Levels of the protein rise on average about 3 months before onset of symptoms or scan evidence of recurrence. Hence, it is an attractive marker to assess the efficacy of new agents such as pazopanib when the tumor volume is low.
The study showed that 31% of the patients had a greater than 50% decrease in CA-125 levels, with median duration of response at 113 days, Prof. Friedlander said. It was generally well tolerated, with a similar spectrum of side-effects seen with other angiogenesis inhibitors.
"Many patients with ovarian cancer will have a recurrence of cancer following initial chemotherapy," he said. "This study clearly demonstrates that pazopanib is an active, well-tolerated drug for women with recurrent ovarian cancer."
The findings of this study support further investigation of the potential role of pazopanib in the management of women with ovarian cancer, Prof. Friedlander added. An international phase III study investigating the drug for ovarian cancer will now go ahead.
"The majority of patients with ovarian cancer will have advanced disease at the time of initial diagnosis," Prof. Friedlander said. "Typically, these patients are managed with surgery followed by combination chemotherapy. Unfortunately most patients will relapse usually within 2 years following the initial therapy. There is therefore a real need to investigate novel agents such as pazopanib to ensure new therapeutic options for patients with ovarian cancer."