Sunitinib in metastatic renal cell carcinoma: Experience from single center study, efficacy and safety

BACKGROUND: The 5-year survival rate for metastatic renal cell carcinoma (RCC) is estimated to be <10%. RCC is highly resistant to chemotherapy. Targeted agents are now first choice of therapy for metastatic RCC such as sunitinib and sorafenib. METHODS: This study is a retrospective analysis of 15 patients having metastatic RCC treated with sunitinib. Apart from three patients, all had clear cell histology. Thirteen patients received dosage of 50 mg/d (4 weeks on/2 weeks off cycles). In 14 patients sunitinib was used as 1st line. The primary end point was objective response rate. Secondary end points were progression free survival (PFS) and safety. RESULTS: Until date of reporting, 3 out of 15 patients are currently on sunitinib. The most common Memorial Sloan = Kettering Cancer Centre poor prognostic factor was an interval of < 1 year between diagnosis and starting of treatment (80%). The objective response rate was 13.66% (complete response [CR] + partial response [PR] = 0 + 2). Clinical benefit rate (CR + PR + stable disease) was 60% (n = 9). Median PFS in this study was 7.5 months, with a range of 2-22 month. Median overall survival (OS) of patients in this study was 12 months with a range of 3-24 month. An impact of the dose or/and number of cycles on response was seen in this study, with patients having average cycles >3 showing better response rates, PFS and OS. Major toxicities seen were fatigue (n = 7), diarrhea (n = 3) and skin rash (n = 4) with majority patients experienced Grade 1-2 toxicities. While Grade 3-4 toxicities include fatigue (n = 1), mucositis (n = 1) and nausea (n = 1). CONCLUSIONS: These results confirm efficacy and safety profile of sunitinib in metastatic RCC, particularly as a first line. Sunitinib produced a 60% disease control rate for metastatic RCC in Indian patients, with acceptable rates of toxicity at a dose of 50 mg daily. Response rates were well matched to other studies confirming the efficacy of sunitinib.