Purpose: Activity has been reported in phase II single-center, open-label studies after administration of low-dose recombinant interferon gamma-1b (rIFN-gamma) to patients with metastatic renal cell carcinoma, with an overall objective response proportion of around 15%. To confirm these data and define the complete response rate, we conducted a multicenter open-label trial in which 204 patients with metastatic renal cell carcinoma were treated with rIFN-gamma.
Patients and methods: Two hundred and seven patients (134 males, 73 females, mean age 59) were enrolled, and 202 were evaluable. rIFN-gamma, 60: microgram/m2, was administered subcutaneously once every 7 days until disease progression.
Results: There were three (1.5%) complete responses and three (1.5%) partial responses, for an overall response proportion of 3% (95% CI: 1.2%, 6.7%). The median response duration was 13.3 months (range: 2 to 23 months). The median survival was 13.4 months (5.5 months to 29.2 months). Three (1%) deaths were observed during the course of study; they were considered to be related to progressive metastatic renal cell carcinoma. Toxicity was minimal, with 14% of patients experiencing grade 3/4 toxicity. The most frequent adverse events were chills (59%), fever (58%), asthenia (53%), nausea (29%), and headache (18%). Multivariate analysis revealed that younger age, higher performance status, higher hemoglobin, and lower LDH were predictive of survival.
Discussion: Recombinant interferon gamma 1b has only minimal efficacy in the treatment of metastatic renal cell carcinoma. Pretreatment variables associated with increased survival were male sex, higher Karnofsky performance status, higher hemoglobin, and low LDH.