Safety report of a phase II trial of irinotecan plus S-1 (IRIS) with cetuximab in patients with KRAS wild type of metastatic colorectal cancer: HGCSG0902.
e14062 Background: IRIS is one of the standard regimens as second line treatment in metastatic colorectal cancer since IRIS demonstrated the non-inferiority to FOLFIRI (FIRIS study) in Japan. We previously presented IRIS plus bevacizumab (ESMO 2010), however; there is still lack of combination data of IRIS plus molecular target drugs. Thus we conduct the study of IRIS plus cetuximab (HGCSG0902) and this is the planned safety analysis for first 20 patients. Methods: HGSCG0902 is a multicenter phase ll study. Eligibility includes histologically confirmed colorectal cancer, previously received oxaliplatin-contained chemotherapy, PS: 0-1, EGFR positive and KRAS wild type. Patients (pts) received S-1 80-120 mg/m2/day p.o. on days 1-14 and irinotecan 100mg/m2 on days 1 and 15 repeated 28 days. Cetuximab administrated 400mg/m2 loading dose and continued 250mg/m2 every week or 500mg/m2 bi-weekly. The primary endpoint was response rate and the secondary endpoints were disease control rate, PFS, OS and safety. Results: Demographics of the 20 enrolled pts were male/female: 13/7, median age: 64.5, colon/rectal: 13/7, PS0/1: 12/8, prior bevacizumab +/-: 15/4 pts. Cetixumab were administrated weelkly/bi-weekly: 9/11 pts. 70% of pts had adverse events (AE). The most common non-hematological AE were diarrhea (85%), acne-like rash (80%), fatigue (75%) and anorexia (60%) and hematological AE were anemia (90%), AST increase (75%) and ALT increase (70%). The main grade 3-4 AE were diarrhea (45%), acne-like rash (20%), anorexia (20%) and stomatitis (20%). These AE were as expected. Nineteen pts stopped the treatment due to progression (52.6%) and AE (36.8%). Conclusions: This safety analysis suggests that IRIS plus cetuximab is well-tolerated and easy to administer.