This study was conducted to determine maximum tolerated dose ( MTD ) , dose-limiting toxicities ( DLTs ) , pharmacokinetics ( PKs ) , and antitumor activity of escalating doses of tivozanib with a modified ( m ) FOLFOX-6 ( leucovorin , 5-fluorouracil [ 5-FU ] , and 85 mg/kg ( 2 ) oxaliplatin ) regimen in patients with advanced gastrointestinal tumors .