Preliminary results of the alternating administration of natural interferon‐α and recombinant interferon‐γ for metastatic renal cell carcinoma

Abstract

To evaluate the efficacy and toxicity of the alternating administration of natural (n) interferon (IFN)-α and recombinant (r) IFN-γ for metastatic RCC. The study comprised 24 patients (median age 60 years, range 42–77), 20 of whom were evaluable for response and all 24 evaluable for toxicity. Initially, nIFN-α was administered subcutaneously on days 1 and 3, and rIFN-γ 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-α and rIFN-γ were administered at the same doses on days 1, 3 and 5, and on days 2 and 4, respectively. There were three complete remissions and two partial remissions, giving a total response rate of 25%. All responders (complete plus partial remission) had undergone nephrectomy. Multiple lung metastases completely disappeared 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 (stable 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 no treatment-related deaths. The alternating administration of nIFN-α and rIFN-γ is an effective treatment for metastatic RCC. This treatment is particularly suitable for patients who have undergone nephrectomy and have lung metastases.