Disclosed is an IV-infusible formulation comprising the compound of Formula II: in a buffered solution having a pH of from about pH 3.4 to about pH 5, said buffered solution comprising citric acid and sodium citrate, and wherein the ratio of citric acid:sodium citrate is about 1 mole of sodium citrate to about 2.4 moles of citric acid, the formulation providing a dosage of from about 0.33 mg/m2 to about 58 mg/m2 of the compound of formula II.