ASCO LOS ANGELES--A review of survival data from a phase I study of intraperitoneal interleukin-2 (IL-2) performed from 1987 to 1990 has shown durable responses in women with refractory ovarian cancer.
Speaking at a media briefing held in conjunction with the American Society of Clinical Oncology meeting, Robert P. Edwards, MD, said that the study was "ahead of its time." Recombinant IL-2 (aldesleukin, Proleukin) had become available in 1985, and giving it to ovarian cancer patients in the IP cavity as locoregional treatment "was really an insightful thing to do," he added.
A phase II study of the treatment is planned at the University of Pittsburgh/Magee-Womens Hospital, where Dr.Edwards is director, Division of Gynecologic Oncology, and if the promising phase I results are confirmed, intraperitoneal IL-2 could offer an effective second-line therapy for patients with recurrent ovarian cancer.
The original University of Pittsburgh investigators, Drs. Herberman and Kirkwood, used escalating doses of two different delivery schedules: 7-day continuous infusion every other week or a weekly 24-hour infusion.
The investigator's initial bias, based on animal data, was that the 7-day infusion would be superior. "However," Dr. Edwards said, "it became clear around 1990 that toxicity with the 7-day infusion was excessive, and the weekly infusion produced more responses, although this did not reach significance."
Dr. Edwards and his colleagues determined long-term survivors from the study by reviewing the patients' charts and contacting survivors. They found that the patients who responded at the lower dose tiers were still alive and free of disease 57 to 84 months after treatment.
"These are patients who had persistent ovarian cancer after receiving very intensive chemotherapy," Dr. Edwards stressed. The majority had received three- drug regimens that included platinum and doxorubicin(Drug information on doxorubicin). All underwent surgical evaluation to document the extent of disease prior to treatment with IL-2.