Methods of treating, preventing or managing cancer, including certain leukemias are disclosed. The methods encompass the administration of enantiomerically pure (+)-1,4-dihydro-7-[(3S,4S)-3-methoxy-4-(methylamino)-1-pyrrolidinyl]-4-oxo-1-(2-thiazolyl)-1,8-naphthyridine-3-carboxylic acid. Also provided are methods of treatment using this compound with chemotherapy, radiation therapy, hormonal therapy, biological therapy or immunotherapy. Pharmaceutical compositions and single unit dosage forms suitable for use in the methods are also disclosed.