Oxaliplatin, irinotecan, and cetuximab in advanced gastric cancer. First efficacy results of a multicenter phase II trial (AGMT Gastric-2) of the Arbeitsgemeinschaft Medikamentoese Tumortherapie (AGMT)

4538 Background: Patients (pts.) suffering from advanced gastric cancer have still a poor prognosis and treatment options are limited. In our previous phase II trial (AGMT-Gastric-1) we could show that the combination of oxaliplatin and irinotecan was well tolerated and showed an objective response rate of 58% (Anticancer Res 28:2901–2906, 2008). This chemotherapy regimen was tested in combination with cetuximab in a multicenter phase II trial. Methods: Oxaliplatin 85 mg/m2 biweekly and irinotecan 125 mg/m2 biweekly were combined with cetuximab 400 mg/m2 loading dose and subsequently weekly 250 mg/m2. 51 patients with histological proven unresectable and/or metastatic gastric adenocarcinoma were treated in a first line setting. Median age: 62 years (range 19–79 years), PS 0: 25 patients, PS 1+2 26 patients, single metastatic site: 24 patients, multiple metastases: 27 patients. Results: Frequently reported adverse events (more than 20% of pts.) were predominantly grade 1 or 2 and included neutropenia (35% of pts.), thrombocytopenia (33%), anemia (73%), nausea (45%), diarrhea (57%), alopecia (22%), and fatigue (37%). Grade 3 and 4 toxicities included neutropenia in 9/1 pts., thrombocytopenia in 1/0 pts., anemia in 3/1 pts., nausea in 2/0 pts., and diarrhea in 7/2 pts. Sensory neuropathy occurred mostly as grade 1 and 2 in 37% of pts., in 7 pts. grade 3 neurotoxicity was observed. Acneiform skin rash grade 1 / 2 / 3 / 4 was reported in 31% / 20% / 6% / 2% of pts. respectively. 16 pts. went off-study due to neutropenia (n=5), nausea/vomiting (n=1), diarrhea (n=1), progressive disease (n=3), toxic colon (n=2), and allergic reaction to cetuximab at first (n=2), second (n=1) or third infusion (n=1). 35 patients are assessable for response with 1 pt. (3%) showing a CR, 21 pts. (60%) a PR, 7 pts. (20%) a SD and PD in 6 pts. (17%). A disease control rate was achieved in 83%. Median time to progression was 24.8 weeks (n=29), median overall survival 38.1 weeks (n=32). Conclusions: The combination of oxaliplatin and irinotecan with cetuximab is feasible, safe and active in advanced gastric cancer. [Table: see text]