Women whose ovarian cancer has returned after multiple treatments may be helped by an investigational drug called VEGF Trap (aflibercept). Researchers from Memorial Sloan-Kettering Cancer Center in New York presented hopeful findings at the annual meeting of American Society of Clinical Oncology.

In their preliminary analysis of 162 women, the drug shrank tumors in some women and kept the disease stable for most participants -- in some cases for months. That's good news because once ovarian cancer has become resistant to multiple types of chemotherapy, patients have few treatment options left.

That was the case for the women in this study. All of them had been treated with 3 or 4 chemotherapy regimens already, but their cancer had returned. They were randomly assigned to 1 of 2 doses of VEGF Trap.

Only about 8% of women in the study saw their tumors shrink, but many more saw their tumors stop growing.

"One of the most meaningful parts of the study that we've seen is that patients who did respond stayed on treatment for quite some time," said lead study author William P. Tew, MD, an oncologist at Memorial Sloan-Kettering Cancer Center.

After 4 weeks of treatment, 85% of patients (138 women) had no tumor growth. At 14 weeks, 41% of participants (67 women) still had stable disease. Although the number of women with stable disease continues to shrink, 6 months after starting the study, 4% of participants (7 women) still have no tumor growth.

Side effects from the drug were "generally reasonable," Tew said. High blood pressure, headaches, voice changes, and fatigue were the most common. These side effects are typical of this kind of drug, he noted. VEGF Trap is an angiogenesis inhibitor -- it keeps blood vessels from forming near the tumor, starving it of the nutrients it needs to grow. Avastin (bevacizumab) is a similar drug.

These types of drugs can sometimes have very serious side effects, including excessive bleeding, blood clots, and holes forming in the intestines (known as bowel perforations). But Tew said there were few instances of these side effects in the study, and the ones that did occur were mild.

That was particularly important for bowel perforations, he added, because other drugs studied in ovarian cancer have caused high rates of bowel perforations -- as much as 11%. In this study the rate was only 1%.

Tew emphasized that the findings are still preliminary and could change as the study continues. The research team still needs to enroll more women to complete the trial. They are hoping to study 200 women in all.

Once the study is complete, the team will be better able to determine just how helpful VEGF Trap is, and which dose is best.

Because VEGF Trap is still an experimental drug that has not yet been approved by the US Food and Drug Administration, it is only available through clinical trials.

Citation: "VEGF-Trap for patients with recurrent platinum-resistant epithelial ovarian cancer: Preliminary results of a randomized, multicenter phase II study." Presented June 3, 2007, at the annual meeting of the American Society of Clinical Oncology. First author: William P. Tew, MD, Memorial Sloan-Kettering Cancer Center, New York.