Phase II trial of thalidomide in renal-cell carcinoma

Background: Thalidomide has been reported to yield anti-tumor activity in cancer. We performed a phase 11 trial of this drug in patients with metastatic renal cell carcinoma to determine its efficacy, Patients and methods: Patients with proven metastatic renal cell cancer, measurable progressive disease and a performance status of 0-2 were enrolled in this study. Thalidomide was given daily at a starting dose of 400 mg, followed by a 400 mg increment to 800 mg and then to 1200 mg with 6-12 weeks at each dose level. The response rate at 6 months was the primary end point. Toxicity,overall survival, tumor vascularization depicted on color Doppler ultrasonography and serum vascular endothelial growth factor, basic fibroblast growth factor, interleukin-12 and tumor necrosis factor-cc levels were secondary end points. Results: Forty patients were enrolled. Two partial responses were observed (5%) and disease remained stable in nine patients after 6 months. Median survival was 10 months. Toxicity was high, with frequent manifestations of fatigue, constipation and lethargy. The incidence of neuropathy detected on electromyography (EMG) attained 70% at 6 months, and 100% in patients on thalidomide for 12 months. Nine patients developed venous thromboembolism during the first 12 weeks of treatment, and three of them experienced pulmonary embolism. One unexpected (and unexplained) death occurred. Conclusions: Despite undisputed, albeit marginal, activity in renal cell cancer, high-dose thalidomide cannot be recommended using this schedule since the level of toxicity is high.