Long-term benefit of sunitinib in patients with metastatic renal cell carcinoma in Latin America: retrospective analysis of patient clinical characteristics

Objective: To describe the clinical characteristics of Latin American patients with metastatic renal cell carcinoma (mRCC) who experienced a progression-free survival (PFS) for at least 15 months following treatment with sunitinib. Patients and methods: In this retrospective analysis, mRCC patients in two institutions in Latin America received sunitinib at a starting dose of either 50 mg/day for 4 weeks followed by 2 weeks off treatment (Schedule 4/2) in repeated 6-week cycles or sunitinib 37.5 mg on a continuous daily dosing schedule. Clinical characteristics, tolerability, and PFS data were collected. Results: Twenty-nine patients with long-term clinical benefit from sunitinib were identified between September 2005 and August 2009. Median PFS was 23 months (range: 15-54 months). Two of the 29 patients with prolonged PFS achieved a complete response and additional eleven had a partial response. Most patients were aged,60 years, had good performance status, favorable or intermediate Memorial Sloan Kettering Cancer Center prognostic risk, and disease limited to one or two sites. Dose reduction was necessary in all patients who started sunitinib at 50 mg/day administered on Schedule 4/2. Adverse events leading to dose reduction included grade 3 hand-foot syndrome, mucositis, fatigue, and hypertension. At the time of data cutoff, four patients were still receiving sunitinib treatment. Conclusion: Extended PFS can be achieved in Latin American patients with mRCC treated with sunitinib. Although the small sample size and retrospective nature of this evaluation preclude the identification of pretreatment predictive factors contributing to this benefit, the current analysis warrants further investigation using a larger data set in this population.