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

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.

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.

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.

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.