RESUMO
BACKGROUND: The aim of this multicenter phase II study was to demonstrate the activity of the epidermal growth factor receptor (EGFR)-targeting monoclonal antibody cetuximab combined with irinotecan in the treatment of Latin American patients with EGFR-expressing metastatic colorectal cancer (mCRC) in whom previous treatment with an irinotecan-containing regimen had failed. PATIENTS AND METHODS: Patients received cetuximab, as a 400 mg/m2 initial infusion followed by 250 mg/m2 weekly, plus the same irinotecan regimen that had previously failed, until the occurrence of disease progression or unacceptable toxicity. The primary endpoint was response. Secondary endpoints included progression-free survival (PFS), duration of response, overall survival (OS), and safety. RESULTS: Seventy-nine patients received treatment. One patient had a complete response, 20 had partial responses, and disease was stabilized in 23 patients, giving an overall response rate of 27% and a disease control rate of 56%. The median duration of response was 23.9 weeks. Median PFS was 17.4 weeks, median OS was 9.2 months, and the 12-month OS rate was 38%. The most common adverse events according to System Organ Class were skin and subcutaneous tissue disorders (91% of the patients). Grade 3/4 adverse events occurred in 45 patients (57%), with the most common being diarrhea (20%), neutropenia (11%), and rash (6%). Seven patients (9%) had grade 3/4 acne-like skin rash. No grade 3/4 infusion-related reactions were reported. CONCLUSION: Cetuximab in combination with irinotecan is active and tolerable in Latin American patients with mCRC progressing on irinotecan, with a safety profile similar to that described in European studies.