AIM:To evaluate the efficacy and safety of cetuxim-ab plus irinotecan in irinotecan-refractory metastatic colorectal cancer (mCRC) patients from South-East Asia and Australia. METHODS:In this open-label,phase Ⅱ study,the main eligibility criteria were epidermal growth factor receptor-positive mCRC with progressive disease within 3 mo of an irinotecan-based regimen as the most recent chemotherapy. Patients received cetuximab 400 mg/m2 initially,then 250 mg/m2 every week,with the same regimen of irinotecan on which the patients had progressed (4 pre-defined regim-ens allowed). The prim-ary objective was evaluation of progression-free survival (PFS) at 12 wk. Secondary objectives included a further investigation of PFS,and an assessment of the overall response rate (ORR),duration of response,time to treatment failure (TTF),overall survival and the safety profile. RESULTS:One hundred and twenty nine patients were enrolled from-25 centers in the Asia-Pacific region and of these 123 received cetuximab plus irinotecan. The most common recent irinotecan regimen used was 180 mg/m2 every 2 wk which had been used in 93 patients (75.6%). The PFS rate at 12 wk was 50% (95% confidence interval (CI,41-59) and m-edian PFS tim-e was 12.1 wk (95% CI:9.7-17.7). The ORR was 13.8% (95% CI:8.3-21.2) and disease control rate was 49.6% (95% CI:40.5-58.8). Median duration of response was 31.1 wk (95% CI:18.0-42.6) and median overall survival was 9.5 mo (95% CI,7.5-11.7). The median TTF was 11.7 wk (95% CI:9.1-17.4). Treatment was generally well tolerated. The most common grade 3/4 adverse events were diarrhea (13.8%),neutropenia (8.9%),rash (5.7%) and vomiting (5.7%).CONCLUSION:In patients from Asia and Australia,this study confirm-s the activity and safety of cetuxim-ab plus irinotecan observed in previous studies in Europe and South America.