Efficacy of Continuous Subcutaneous Infusion Therapy Using Interferon α and the Possible Prognostic Indicator of TNF-α in Renal Cell Carcinoma

Background :
In an attempt to improve efficacy by escalating the dose and maintaining higher serum concentrations over a long period of time, this study examines continuous interferon α (IFNα) subcutaneous infusion therapy in patients with renal cell carcinoma (RCC).
Methods :
Seven of 11 patients with RCC had evaluable metastatic lesions. A highly purified natural human IFNα was injected subcutaneously via an infuser pump for 5 consecutive days, followed by a 2-day rest period (25 million IU/week). The treatment was continued for a period of 15 weeks. Serum concentrations of IFNα, IL-1α, IL-1β, TNF-α, and IFNγ were measured at intervals throughout the study period.
Results :
Two of the 7 patients with evaluable lesions achieved a partial response (overall response rate, 29%), while 1 achieved a partial response only to lung metastasis. These 3 cases were defined as responders. No difference was found in the concentration of serum IFNα between responders and nonresponders, however, a significantly higher concentration of serum TNF-a was observed in responders (P<0.05, Mann-Whitney U test). Five cases (45%) had moderate to severe adverse effects, including depression (n = 1), eyeground hemorrhage (n = 2), and general fatigue (n = 2).
Conclusion :
Appropriate patient selection may be necessary for subcutaneous continuous infusion therapy for the treatment of metastatic RCC. Also, the serum concentration of TNF-α measured during the course of treatment reflected well on the outcome of IFNα therapy.