Losartan + Sunitinib in Treatment of Osteosarcoma

Losartan will be administered orally daily on days 1-42 (6 weeks) with dose level assignments. Dosing will be performed based on weight in kilograms and rounded to the nearest 12.5 mg (half of 25 mg tablet). Dose level 1 dosing will not exceed 50 mg daily, dose level 2 dosing will not exceed 100 mg daily, and dose level 3 dosing will not exceed 150 mg total daily (75 mg twice daily). Doses should be taken at approximately the same time daily and patients should fast for at least 4 hours prior to dosing

Sunitinib will be administered orally daily on days 1-28 (4 weeks), followed by 14-day rest period (2 weeks). Dosing will be performed based on body surface area (BSA) in mg/m2. Sunitinib is given as capsules or liquid formulation. Doses should be taken at approximately the same time daily.