Fatigue in patients with advanced renal cell carcinoma receiving sunitinib on an intermittent versus continuous dosing schedule in a randomized phase II trial

A phase II trial in advanced renal cell carcinoma (RCC) found efficacy or safety between patients receiving oral sunitinib 50 4 weeks followed by 2-week off-treatment (Schedule 4/2) and 37.5 mg continuous daily sunitinib. We hypothesized that fatigue more variable "on-off" effect with the 4/2 schedule. A total of completed two fatigue-related items on Days 1 and 29 of each Mean absolute slopes were compared across treatments. A planned item "I feel fatigued" demonstrated that the mean absolute slope Schedule 4/2 compared to continuous dosing (0.042 vs. 0.032, P = analysis based on the change from Day 1 to Day 29 (0.52 vs. 0.21, and, separately, Day 29 to the next Day 1 (-0.38 vs. -0.05, P < the changes to be significantly larger in Schedule 4/2 than "I have a lack of energy" showed a similar pattern graphically, planned analysis was not statistically significant based on the but was when Day 1 to Day 29 and Day 29 to Day 1 changes separately. The 4/2 arm was associated with a greater degree of fatigue reflecting a possible "on-off" effect whereby patients schedule reported less fatigue at the beginning of each cycle 29. The findings can inform care for individuals with advanced intermittent dosing of sunitinib.