PHASE-II STUDY OF INTERMITTENT LOW-DOSE IFN-GAMMA IN METASTATIC RENAL-CELL CANCER

Background: We studied the clinical efficacy and toxicity of a low-dos e interferon-gamma (IFN-gamma) regimen in patients with metastatic ren al cell carcinoma (RCC). Methods: Eighteen unselected patients with me tastatic RCC (median Karnofsky 80%; median sites of metastases = 2; 10 patients were pretreated with immunotherapy) were included in this pr otocol. They were treated with IFN-gamma at 150 mu g s.c. once a week until tumor progression. Each treatment cycle consisted of 6 weeks of therapy on an outpatient basis followed by a pause of 2 weeks. Results : Toxicity was generally mild with low-grade fever predominating. Of 1 7 patients evaluable for response, one partial remission (5 months) wa s observed in a patient with pulmonary and mediastinal metastases and 4 further patients had stable disease (5, 7, 7 and 12 months). Four pa tients received IFN-alpha IL-2 subsequent to treatment with IFN-gamma. Interestingly the patient who achieved a partial remission had a furt her partial response to IFN-alpha and IL-2 following relapse under the rapy with IFN-gamma. Conclusion: Treatment with low-dose IFN-gamma had limited clinical efficacy in our unselected patient group.