Irinotecan will be administered as a 60-minute intravenous infusion daily for 5 consecutive days, followed by a 2 day rest, and followed by an additional 5 consecutive days course [(qd x 5) x 2]. Twenty-one days from the first dose will be considered one cycle of therapy. Cefpodoxime will be given orally at 10 mg/kg/day divided BID, starting 2 days prior to the beginning of the first course of irinotecan, and will be continued for the duration of study participation.