Results of weekday-on and weekend-off administration schedule of sunitinib therapy for advanced renal cell carcinoma.

Background: Sunitinib is widely prescribed as first-line therapy for metastatic renal cell carcinoma. To reduce the ratio of severe adverse events and improve the relative dose intensity, we prospectively tried our own alternative medication schedule, which we called the "weekday-on and weekend-off regimen". Here we report the results of this regimen compared to the conventional medication schedule.

Methods: In total, 58 patients were enrolled in this study. Twenty patients were treated under the alternative schedule (group I: weekday-on and weekend-off regimen) and 38 patients were treated using the conventional schedule (group II: 4 weeks on and 2 weeks off regimen). The relative dose intensity (6W-RDI) and prognoses were compared between the two groups.

Results: Median 6W-RDI of all the patients was 75.0%. Group I patients demonstrated significantly higher 6W-RDI compared to group II (77.2 vs. 70.4%) (p = 0.019). Multivariate analysis showed that the alternative sunitinib administration schedule was significantly associated with maintaining 6W-RDI above 75% for RCC patients treated with sunitinib (OR 3.592, 95% CI 1.042-12.383, p = 0.043). On the other hand, there were no significant differences between 2 groups regarding occurrence rate of severe adverse events and prognosis by multivariate analysis.

Conclusions: We report the results of an alternative medication schedule, the "weekday-on and weekend-off regimen", as a means of increasing 6W-RDI for metastatic RCC patients.