Retreatment of Irinotecan in Later Lines of Therapy for Metastatic Colorectal Cancer: A Retrospective Study

Background: Due to few efficacious options in later lines of therapy in metastatic colorectal cancer (mCRC), there has been considerable interest in the possibility of retreatment with previously administered agents. This study investigated the efficacy and safety of irinotecan retreatment (IRI2) in patients with refractory mCRC. Methods: We performed a retrospective analysis of patients with mCRC who were retreated with irinotecan-based regimens. The retreatment regimens with anti-epidermal growth factor receptor therapies were excluded. Results: A total of 64 patients were included. Patients had a median age of 56 years and were offered mainly in the setting of third- or fourth-line therapy with IRI2. The disease control rate was 78.2% including an objective response of 23.5%. Median progression-free survival and overall survival were 5.5 and 19.3 months, respectively. The most frequent grade 3 or higher toxicities were nausea/vomiting (27.9%) and neutropenia (25%). Conclusion: IRI2 might be a reasonable option for heavily pretreated patients with mCRC who achieved disease control with prior irinotecan therapy.