Drug delivery devices and methods are provided for administering gemcitabine to a patient in need of treatment of bladder cancer by intravesically administering gemcitabine into the bladder of the patient to achieve a sustained concentration of the gemcitabine in urine in the bladder sufficient to produce a therapeutically effective concentration of the gemcitabine in the tissues of the bladder. In embodiments, the local administration into the patients bladder is at a mean average amount of from 1 mg/day to about 300 mg/day of the gemcitabine
