A phase ii study of gemcitabine and capecitabine in patients with advanced renal cell cancer: Southwest Oncology Group Study S0312

Gemcitabine plus capecitabine has moderate efficacy in patients with advanced renal cell cancer (RCC) but has considerable toxicity. We evaluated the efficacy and toxicity of a modified dose-schedule of this doublet in patients with metastatic RCC. Chemotherapy-naive patients were treated with gemcitabine at 900 mg/m2 on days 1, 8, and 15 and with capecitabine at 625 mg/m2 twice daily on days 1 through 21, and every 28 days thereafter. The primary end point was response rate (RR). No further evaluation of this regimen would be pursued if the RR was ≤ 5%. In an exploratory analysis, we also evaluated potential markers of prognosis and treatment response, including thymidylate synthase, PTEN, pAKT, pmTOR, XRCC1, and ERCC1. Of 43 patients, 1 was ineligible and 2 were not analyzable. There was 1 complete response and 3 partial responses, for an overall RR of 10% (95% CI = 3, 24). Nineteen patients (48%) had stable disease. The 6-month freedom-from-treatment-failure and overall survival rates were 20% (95% CI = 8, 32) and 75% (95% CI = 62, 88), respectively. Median survival time was 23 months (95% CI = 10, 37). One patient each experienced grade 4 neutropenia, fatigue, thrombocytopenia, and hemolysis with renal failure. The most common grade 3 toxicities were neutropenia (12 patients), fatigue (5), and leucopenia (4). Patients with a best response of stable disease or better were more likely to have decreased expression of PTEN and increased expression of pmTOR. Gemcitabine plus capecitabine at this reduced dose-schedule benefits a small percentage of patients with RCC with an acceptable toxicity profile.