[Second-line thalidomide/IL-2 therapy in metastatic kidney cancer--results of a pilot study].

PURPOSE: On the basis of promising first-line data we have evaluated the safety and efficacy of a combination therapy comprising interleukin-2 (IL-2) and thalidomide in patients with metastatic renal cell carcinoma (RCC) refractory to both immuno- and chemotherapy.

PATIENTS AND METHODS: 14 patients with progressive metastatic RCC, in whom prior immunochemotherapy had failed but who desired further active therapy, were enrolled in this study. Oral thalidomide was started at 200 mg/d and escalated after two days to 400 mg/d at week 0. IL-2 at 7 MIU/m (2) was given by subcutaneous injection, starting at week 1, days 1 to 5, weeks 1 to 4, with no IL-2 at weeks 5 and 6. The response was assessed every other therapy cycle.

RESULTS: 12 patients were evaluable for response. There was no objective response; 4 patients showed stable disease for 21, 15, 13 and 9 months, respectively. Toxicities were predominantly grade 1 - 3 and included somnolence and constipation, as well as flu-like symptoms associated with IL-2. However, one patient developed serious constipation which led to a paralytic ileus and discontinuation of treatment. Another patient left the study after seven weeks due to increasing confusion. 11 patients required IL-2 dose reduction. Time on therapy ranged from 3 - 44 weeks (median, 19 weeks). Median overall survival was 22 months. Up to date, all patients have discontinued treatment.

CONCLUSIONS: We conclude that outpatient administration of thalidomide/IL-2 is feasible in patients with heavily pretreated and progressive RCC who desire further active treatment. However, toxicity and costs are considerable and the clinical benefit is uncertain. Therefore thalidomide/IL-2 may not represent a promising therapeutic approach for this subgroup of patients.