ORLANDOIrinotecan, also known as CPT-11 (Camptosar), administered every 3 weeks to patients with fluorouracil(Drug information on fluorouracil) (5-FU)-refractory colorectal cancer produced response rates and toxicity profiles similar to irinotecan(Drug information on irinotecan) given weekly in a phase III study. Charles S. Fuchs, MD, MPH, Dana-Farber Cancer Institute, reported the results at the 38th Annual Meeting of the American Society of Clinical Oncology (abstract 514).
"Our findings are consistent with other efficacy results of phase III trials of single agent CPT-11 in 5-FU-refractory colorectal cancer," Dr. Fuchs said. "In addition, these results continue to support the close monitoring of patients treated with CPT-11."
Patients were randomized in a 1:2 ratio to weekly or every 3-week irinotecan. The first group received a weekly schedule of 125 mg/m² for 4 consecutive weeks followed by a 2-week rest. The second arm was given 350 mg/m² every 3 weeks.
Patients who were age 70 or older, had a performance status of 2, or had received prior pelvic radiotherapy started irinotecan at 300 mg/m². About 55% of the patients in the 3-week arm started at the lower dose.
Patients were managed with antiemetics and antidiarrheal medication as needed and atropine(Drug information on atropine) for cholinergic symptoms during the infusion. Prophylactic atropine was not permitted during the first treatment infusion.
Eligibility included patients with measurable metastatic colorectal cancer that had progressed within 6 months of 5-FU-based chemotherapy for metastatic disease or had relapsed within 12 months of adjuvant 5-FU therapy. Patients also were required to have an ECOG performance status of 2 or less and adequate laboratory parameters, including a serum bilirubin of no greater than 1.5 mg/dL. Researchers excluded patients treated in the past with irinotecan.