PROBLEM TO BE SOLVED : To provide pharmaceutical compositions for treating human solid tumors such as cancer. SOLUTION : Disclosed herein is a pharmaceutical compositions for a) on Day 1, administering an IV bolus containing 10-1000 mg/m2 (BSA) of 5-FU (or an analog or prodrug thereof); then b) either simultaneously or after a period of from 10 min to 4 hours, administering one or more IV boluses, each containing 5-1000 mg/m2 of [6R]-5, 10-methylenetetrahydrofolate; and then, d) on Day 2, administering one or more IV boluses each containing 10-1000 mg/m2 (BSA) of 5-FU (or an analog or prodrug thereof). SELECTED DRAWING : Figure 2 COPYRIGHT : (C)2019, JPO&INPIT