Patients who are on hemodialysis. Requirement for hemodialysis or peritoneal dialysis Patients receiving hemodialysis or peritoneal dialysis Patients who require hemodialysis Estimated creatinine clearance < mL/min or use of renal replacement therapy (e.g., hemodialysis, continuous renal replacement therapy, peritoneal dialysis) within days prior to Day Receiving renal replacement therapy, hemodialysis, or peritoneal dialysis Renal failure requiring peritoneal dialysis or hemodialysis Renal failure requiring hemodialysis or peritoneal dialysis REGORAFENIB EXCLUSION CRITERIA: Renal failure requiring hemodialysis or peritoneal dialysis Patients who are on hemodialysis Patients who are on hemodialysis Severe renal insufficiency (estimated creatinine clearance < mL/min) or on hemodialysis at the time of randomization or likely to require dialysis during the study. Patients who are on hemodialysis. Patients who are on hemodialysis Expected requirement for hemodialysis while on study therapy Patients requiring hemodialysis Renal insufficiency requiring hemodialysis or peritoneal dialysis Patients who are on hemodialysis. Renal failure requiring hemodialysis or peritoneal dialysis Requirement for hemodialysis or peritoneal dialysis Patients on hemodialysis e. Renal failure needing hemodialysis or peritoneal dialysis Patients who are on hemodialysis. Expected requirement for hemodialysis while on study therapy Serum creatinine level > . x the upper limit of normal (ULN), chronic renal failure requiring hemodialysis or peritoneal dialysis. Subjects on hemodialysis or peritoneal dialysis Serum creatinine will not be used to exclude patients; patients on renal-replacement therapy (e.g., hemodialysis or peritoneal dialysis) will be eligible to participate Subjects who require routine/intermittent hemodialysis or continuous peritoneal dialysis (due to inability to provide appropriate dosing schedule for oseltamivir) at Baseline. CRRT modalities are allowed. Renal failure requiring hemodialysis or peritoneal dialysis. Renal failure requiring hemodialysis or peritoneal dialysis Receiving renal replacement therapy, hemodialysis, or peritoneal dialysis Patient is not currently on hemodialysis and/or peritoneal dialysis for management of chronic kidney disease or acute failure/conditions. Subjects currently receiving hemodialysis Stage chronic kidney disease or need for hemodialysis Oliguric acute renal failure (urine output < ml/day) unless already on hemodialysis Presence of significant renal disease or hemodialysis which would result in dramatic reductions of systemic levocarnitine levels Patients on hemodialysis