Preliminary results of the alternating administration of natural interferon-alpha and recombinant interferon-gamma for metastatic renal cell carcinoma

Objective To evaluate the efficacy and toxicity of the alternating administ ration of natural (n) interferon (IFN)-alpha and recombinant (r) IFN-gamma for metastatic RCC. Patients and methods The study comprised 24 patients (median age GO pears, range 42-77), 20 of whom were evaluable for response and all 24 evaluable f or toxicity. initially, nIFN-alpha was administered subcutaneously on days 1 and 3, and rIFN-gamma on day 2, for 1-2 weeks in the evening or at night, both at doses of 3 MU, If this regimen was tolerated, nIFN-alpha and rIFN- gamma were administered at the same doses on days 1, 3 and 5. and on days 2 and 4, respectively, Results There were three complete remissions and two partial remissions, gi ving a total response rate of 25%, All responders (complete plus partial re mission) had undergone nephrectomy, Multiple lung metastases completely dis appeared from four responders. The median and maximum time to remission in the responders were 2 and 7 months, respectively, The survival time of the responders was significantly longer than that of those not responding (stab le and progressive disease. P = 0.0202). Toxicities were mostly Limited to WHO grades 1 and 2, with grade 3 leucopenia and grade 4 hepatic dysfunction in only one patient each. These toxicities were transient and there were n o treatment-related deaths. Conclusion The alternating administration of nIFN-alpha and rIFN-gamma is a n effective treatment for metastatic: RCC. This treatment is particularly s uitable for patients who have undergone nephrectomy and have lung metastase s.