Oxaliplatin, irinotecan and cetuximab in advanced gastric cancer. A multicenter phase II trial (Gastric-2) of the Arbeitsgemeinschaft Medikamentose Tumortherapie (AGMT)

Abstract

Background: Patients suffering from advanced gastric cancer still have a poor prognosis and treatment options are limited. In our previous phase II trial (AGMT-Gastric-1), we showed that the combination of oxaliplatin and irinotecan was well tolerated and effective. The same chemotherapy regimen was now tested in combination with cetuximab in a multicenter phase II trial.

Patients and methods: Oxaliplatin at 85 mg/m(2) biweekly and irinotecan at 125 mg/m(2) biweekly were combined with cetuximab at 400 mg/m(2) loading dose and subsequent weekly infusions of 250 mg/m(2). Fifty-one patients with histologically proven unresectable and/or metastatic gastric adenocarcinoma were treated in the first line setting. The median age was 62 years. A single metastatic site was found in 24 patients, 27 patients had multiple metastatic sites.

Results: Frequently reported adverse events (in more than 20% of patients) were predominantly grade 1 or 2 and included neutropenia (35%), thrombocytopenia (33%), anemia (73%), nausea (45%), diarrhea (57%), alopecia (22%), and fatigue (37%). Grade 3/4 toxicities included neutropenia in 9/1 patients., thrombocytopenia in 1/0 patients, anemia in 3/1 patients, nausea in 2/0 patients, and diarrhea in 7/2 patients. Sensory neuropathy occurred mostly as grade 1 and 2 in 37% of patients, grade 3 neurotoxicity was observed in 7 patients. Acne-like rash grades 1/2/3/4 were reported in 31%/20%/6%/2% of patients respectively. Thirteen patients discontinued the study due to neutropenia (n=5), nausea/vomiting (n=1), diarrhea (n=1), toxic colon (n=2), and allergic reaction to cetuximab at first (n=2), second (n=1) or third infusion (n=1). Thirty-five patients were assessable for response, with 1 patient (3%) showing a complete response, 21 patients (60%) a partial response, 7 patients (20%) a stable disease, and 6 patients (17%) a progressive disease respectively. The median time to progression was 24.8 weeks, median overall survival was 38.1 weeks. All patients tested had a wild type KRAS status.

Conclusion: The combination of oxaliplatin and irinotecan with cetuximab is safe and its action established in advanced gastric cancer.