[The safety and efficacy of sunitinib using a modified regimen (2 weeks on/1 week off) for treatment of metastatic renal cell carcinoma].

We prospectively investigated the safety and efficacy of sunitinib using a modified regimen (2 weeks on/1 week off) in 24 patients (22 males, 2 females ; age range 39-86 years, median 64 years) with metastatic renal cell carcinoma (RCC). During the observation period (3-62 weeks, median 21 weeks), thrombocytopenia was seen in 13 (54.2%), leukopenia in 11 (45.8%), hand-foot syndrome in 5 (20.8%), hypertension in 4 (16.7%), and hypothyroidism in 3 (12.5%) patients, while grade 3 or higher adverse events were found in 4 (16.7%), 1 (4.2%), 1 (4.2%), 2 (8.3%), and 0 patients, respectively. Of the 21 patients evaluable for response, 5 (23. 8%) showed partial response, 8 (38.1%) stable disease, and 8 (38.1%) progressive disease. This new modified regimen may lead to a reduction in adverse events for treatment of patients with metastatic RCC as a substitute for the standard dosing regimen of sunitinib.