The present invention provides a novel dosage principle for compounds of formula I and pharmaceutically acceptable derivatives thereof as defined in the claims, wherein said compound or pharmaceutically acceptable derivative thereof is intravenously administered to said patient over a period of at least about 8 hours, wherein the dose of the compound of formula I or pharmaceutically acceptable derivative thereof is at least the molar equivalent of about 45mg/m2 of the dihydrochloride salt of the compound of formula I-B as defined in the claims.
