Subcutaneous low-dose recombinant interleukin 2 and alpha-interferon in patients with metastatic renal cell carcinoma

A double-institution phase II study was performed in patients with metastatic renal cell carcinoma treated subcutaneously (s.c.) with interleukin 2 (IL-2) and alpha-interferon (INF-alpha). Thirty-eight patients were treated over a course of 7 weeks. Initially (day 1 + 2) patients received s.c. IL-2 at 18 x 10(6) IU m-2. During the following 6 weeks, patients received s.c. IL-2 at 3.6 x 10(6) IU m-2 for 5 days per week and s.c. INF-alpha at 5 x 10(6) for 3 days per week. Thirty-eight patients were evaluated for response. An objective response was seen in seven patients (18.4 +/- 12.3%), with one complete response and six partial responses. Median duration of response was 6.7 months. Toxicity could be evaluated in 38 patients and was limited. Mild to moderate toxicity included fever (97%), fatigue or malaise (76%), nausea or vomiting (50%), anorexia (32%), hypotension (26%), neurological disturbances (26%) and hypercreatininaemia (39%). In addition, four grade IV haematological toxicities were noted. No cardiac side-effects were seen. IL-2 and INF-alpha given by this schedule can be safely administered in an outpatient setting. The objective response rate was similar to our previous treatments with high-dose IL-2 given as a continuous infusion.