OBJECTIVES: To assess clinical outcomes among patients with metastatic renal cell carcinoma (mRCC) in Latin America who switched from the 4/2 (4 weeks on/2 weeks off) to the 2/1 (2 weeks on/1 week off) schedule of first-line sunitinib.

METHODS: Oncologists in Argentina, Brazil, Colombia, and Ecuador retrospectively reviewed charts of adult patients diagnosed with mRCC. Patients were required to have switched first-line sunitinib from the 4/2 to the 2/1 schedule or initiated on the 2/1 schedule from January 2014 through June 2018. Patient characteristics, treatment patterns, treatment-related outcomes, and adverse events (AEs) were described.

RESULTS: Data for 57 patients were extracted across 7 Latin American sites. Of patients who switched from 4/2 to 2/1 (n=42), 73.8% switched schedule due to AEs and after switching 9.5% of patients stopped treatment due to AEs. Severity of diarrhea and/or mucositis decreased after schedule switch. No patient initiating on the 2/1 schedule (n=15) stopped because of AEs. Among patients who switched from 4/2 to 2/1 schedule, the median duration was 3.9 (4/2 schedule) and 6.3 (2/1 schedule) months. Among patients who initiated on the 2/1 schedule, the median duration was 9.2 months. Complete response was achieved by 0% on the 4/2 schedule and 14.0% on the 2/1 schedule (including patients who switched and initiated on 2/1 schedule); partial response was achieved by 38.1% on the 4/2 schedule and 33.3% on the 2/1 schedule; stable disease was achieved by 28.6% on the 4/2 schedule and 33.3% on the 2/1 schedule. The main reason for sunitinib discontinuation was disease progression.

CONCLUSIONS: Patients who initiated first-line sunitinib treatment on the 4/2 schedule switched to 2/1 schedule primarily due to AEs. Compared with the 4/2 schedule, patients received sunitinib on the 2/1 schedule for a longer duration potentially because of its better safety profile.