Continuous, nonconventional sunitinib dosing viable in metastatic renal cell carcinoma

Alternative dosing regimens of sunitinib are feasible and appear to be more effective than standard dosing for the treatment of patients with metastatic renal cell carcinoma, reports a new study.

The investigators enrolled metastatic renal cell carcinoma patients treated with sunitinib between 1 July 2007 and 1 July 2011. They performed a retrospective review of medical records and dispensing data to categorize sunitinib dosing as intermittent (4 weeks treatment followed by 2 weeks rest), continuous (continuous daily dosing) or nonconventional (2 weeks on/1 week off).

Overall survival associated with the different dosing regimens was the primary outcome. Secondary outcomes were progression-free survival and incidence of treatment cessation due to adverse effects.

Of the 180 patients included, 120 (67 percent) received intermittent dosing, 32 (18 percent) continuous dosing and 28 (16 percent) nonconventional dosing.

Overall survival was comparable between continuous and intermittent dosing regimens (median, 13 vs 9 months; hazard ratio [HR], 0.67, 95 percent confidence interval, 0.43–1.06; p=0.088) and significantly better with nonconventional vs intermittent dosing (median, 23 vs 9 months; HR, 0.55, 95 percent CI, 0.34–0.90; p=0.016).

Compared with intermittent dosing, both continuous (median, 9 vs 4 months; HR, 0.61, 95 percent CI, 0.40–0.94; p=0.025) and nonconventional dosing (median, 10 vs 4 months; HR, 0.61, 95 percent CI, 0.39–0.95; p=0.03) were associated with longer progression-free survival.

One in five patients (20 percent) stopped treatment with sunitinib due to adverse effects. This finding was similar to that of previous sunitinib trials.