Interferon Plus Interleukin-2 Is The Optimal Treatment To Induce Responses In Metastatic Renal Cell Cancer
Sylvie Négrier, M.D., associate professor, Department of Medical Oncology, Centre Leon Berard (Lyon, France), presented the results of another study demonstrating the effects of interferon, as well as another cytokine, interleukin-2, in advanced renal cell carcinoma (RCC). According to Dr. Négrier, despite the large number of studies evaluating the effects of interferon or IL-2 in metastatic RCC in the past decade, the role of each cytokine or their comnbination has not yet been clearly defined.
The main objective of the multicenter CRECY study (conducted by the French Immunotherapy Group of the French Federation of Cancer Centers) was to evaluate the response rate, duration of response and toxicity of each therapy. Four hundred and twenty-five (425) patients were tandomly assigned to receive on of three regimens: continuous intravenous infusion of IL-2 for five days from Day 1 through Day 5, and then Day 12 through Day 15; subcutaneous interferon three times per week; or a combination of the two drugs. Patients who did not respond to one cytokine could cross-over and receive the other one. Tumor reponses were evaluated 10 weeks after treatment started.
The results showed that combination therapy was superior to a single agent. The objective response rate, defined as tumor shrinkage of at least 50%, was 6.5% for the IL-2 group, 7.5% for the interferon group, and 18.6% for the combination group. The event-free survival rate at one year was 13.8% for the IL-2 group, 9.7% for the interferon group, and 20.9% for the IL-s plus interferon group. The toxic death rate was 7.9% for the IL-2 group, 0.7% for the interferon group, and 3.6% for the combination therapy group.
"This study demonstrates the additive effects that can be achieved by combining two cytokines," Lynn Mara Schuchter, M.D., assistant professor of medicine, University of Pennsylvania Cancer Center (Philadelphia, PA), said at a press briefing today. "While on their own, IL-2 and interferon produced some response against the disease, the combination of the two is clearly superior with regard to response rate and event-free survival in this study."