Like most women with ovarian cancer, 44-year-old Christine Sable of Lancaster, Pennsylvania, did not discover she had the disease until it was in the advanced stages and had spread to other areas of the abdomen. She understood the gravity of the situation: “Most women with ovarian cancer live only one to three years,” she says. “The vast majority do not make it much longer than that. I knew my chances of recurrence were very high—75 to 80 percent at that particular stage—and that the disease would likely recur within a year or two. Once it recurs, it is difficult to cure.”

After aggressive surgery and chemotherapy, the only other option her doctor could offer was more chemotherapy. But the first round had been “very hard,” Sable recalls. “I wanted to find something that would work with my own immune system and not be so harsh on my body.”

Then she learned about a Phase I clinical trial of an ovarian cancer vaccine developed by Kunle Odunsi, MD, PhD, Surgeon in Gynecologic Oncology and Co-Leader of the Tumor Immunology and Immunotherapy Program at Roswell Park Cancer Institute. The vaccine is designed to induce an immune response in the significant number of women whose ovarian tumors express the antigen NY-ESO-1.

Enrollment was open to patients who had completed front-line therapy, whose tumors were positive for NY-ESO-1, and who had no further evidence of disease; Sable fit the profile. She says the day she was accepted into the study was “one of the most exciting days of my life.” She began treatment at RPCI in February 2004, and her immune system responded so strongly to the first five doses of vaccine that she received another five, then another five, each time experiencing a better response—with no side effects. Now 49 and still cancer-free, she returns to RPCI just once a year for continued monitoring.

The trial in which she is participating enrolled 18 patients with epithelial ovarian cancer. To date, it has resulted in median progression-free survival of 19.0 months, with no major toxicity observed. Odunsi and his research team found that the vaccine induced antibody and T-cell responses in patients, and that vaccine-induced T cells were able to recognize NY-ESO-1-expressing tumor cells. “Furthermore,” notes Odunsi, “we detected vaccine-induced immune cells in patients up to 12 months after immunization, suggesting a long-lasting effect.”

The clinical trial was supported by the Cancer Vaccine Collaborative program of the Cancer Research Institute and Ludwig Institute for Cancer Research, and results were reported in the July 25, 2007, issue of Proceedings of the National Academy of Sciences (vol. 104, no. 31).

Dr. Odunsi is currently leading a team of RPCI researchers at work on improving the vaccine’s effectiveness. Such immunotherapies provide an important new focus in the search for better treatments for ovarian cancer, which continues to have a high mortality rate.

Sable says participating in the trial “was a very good experience; I was very well cared for. To have had this many years cancer-free is really pretty amazing.”

Patients with epithelial ovarian, fallopian tube or primary peritoneal carcinoma are currently being recruited for a Phase II clinical trial of the vaccine. For more information, contact Odunsi at Kunle.Odunsi@roswellpark.org or call 1-716-845-8376.