ABSTRACT
<p><b>OBJECTIVE</b>To investigate the efficacy and safety of sunitinib as first-line therapy for metastatic renal cell carcinoma (mRCC) on a 2 weeks on/1 week off intermittent dosing schedule.</p><p><b>METHODS</b>A total of 11 mRCC patients were enrolled to receive sunitinib 50 mg/day in 2 weeks on/1 week off schedule per 6 weeks till disease progression or intolerable toxicity occurred. The primary end point was progression free survival (PFS), the secondary end points were overall survival (OS), incidence of adverse effects and objective response.</p><p><b>RESULTS</b>The objective response rate in the 11 cases was 45.5% and disease control rate 72.7% (partial response n = 5, stable disease n = 3). Till the last follow up on Dec 2013, the median PFS was 17.0 months (95% CI 7.3 to 26.7 months), and median OS 26.0 months (95% CI 2.2 to 49.8 months). The common adverse events included leucopenia, thrombocytopenia, diarrhea, mucositis and hand-foot skin reaction. Dose reduction to 37.5 mg was seen only in 2 patients without discontinuation.</p><p><b>CONCLUSIONS</b>Sunitinib on an intermittent dosing schedule 2 weeks on /1 week off as first-line therapy for mRCC patients shows a good efficacy and tolerance, with less grade 3-4 drug-related toxicities and a tendency of prolonged PFS in mRCC patients.</p>