Purpose: A single-institution phase II study was undertaken to evaluate the efficacy and toxicity of interleukin-2 (IL-2) administered by subcutaneous injection.
Patients and methods: Twenty-seven unselected patients (15 male) with a mean age of 60 years (range, 42 to 76 years) who had advanced renal cell cancer were treated as outpatients. IL-2 was given once a day, 5 days per week for 6 weeks. During the first 5-day cycle, 18 x 10(6) IU was given once daily; in the following cycles, the doses in the first 2 days were reduced to 9 x 10(6) IU. After a 3-week rest period, treatment was repeated in patients who had a response or stable disease (SD). To prevent pyretic reactions, patients also received acetaminophen (250 to 500 mg given orally every 4 to 6 hours).
Results: After 6 weeks, 26 patients were assessable for response. Two patients (8%) had a complete remission (CR), four (15%) had a partial remission (PR), and 13 (50%) had SD. A second cycle of 6 weeks was given to 19 patients; one patient with a PR and six with SD showed progression. Duration of the CR was 17+ and 19+ months, and length of the PR was 2, 8, 11, and 11+ months. The median survival of the patients who were nonresponders and responders was 10 and 20+ months, respectively, and for all patients was 13 months. One patient died as a result of myocardial infarction and brain stem ischemia. Systemic side effects in the other patients were tolerated and accepted, and included transient inflammation and local induration at the injection sites, fever and chills, and nausea.
Conclusion: Subcutaneous IL-2 is clinically active, has an acceptable toxicity, and can be given to patients with concomitant disease.