4070 Background: There are only limited treatment options for advanced gastric cancer. Development of new treatment options is therefore warranted. The aim of this study was to evaluate the safety, feasibility and efficacy of an outpatient Oxaliplatin/Irinotecan combination in patients suffering from unresectable, locally advanced and/or metastatic gastric cancer. Methods: The combination of Oxaliplatin 85 mg/m2 biweekly with Irinotecan 125 mg/m2 biweekly was chosen since it has been shown in colorectal cancer that a biweekly dose of at least 85 mg/m2 oxaliplatin is superior to a lower dose and toxicity of Irinotecan is much lower if given fractionated into two doses. Furthermore the Irinotecan dose below MTD considers concerns about increased toxicity in gastric cancer patients. Results: 43 patients with histologically proven unresectable and/or metastatic gastric adenocarcinoma and no previous palliative chemotherapy and/or immunotherapy were selected. Median age: 61 years (range 32–81 years), male/female ratio: 24/19, PS 0:11 patients, PS <3:32 patients, locally advanced cancer 5 patients, single metastatic site: 19 patients, multiple metastases: 19 patients, previously adjuvant radiochemotherapy: 4 patients. This outpatient regimen was generally well tolerated. Frequently reported adverse events (more than 20% of patients) were grade 1 or 2 and included neutropenia (44% of patients), thrombocytopenia (30%), anemia (77%), nausea 67%), diarrhea (51%), alopecia (35%). Grade 3 and 4 toxicities included neutropenia in 2/43 pts., anemia in 3/43 pts., nausea in 2/43 pts., and diarrhea in 4/43pts. 5 patients were taken off-study due to toxicity (asthenia, nausea, reversible renal failure, diarrhea). Sensory neuropathy occurred only as grade 2 in 14%, no grade 3/4 neurotoxicity was observed. For response 38 patients are assessable with 3 pts. (8%) showing a CR, PR in 19 pts. (50%), SD in 11 pts. (29%), PD in 5 pts. (13%). Median TTP was 5.3 months and median OS 9.5 months. Conclusions: The outpatient combination of a biweekly Oxaliplatin/Irinotecan chemotherapy is well tolerated and shows a response rate within the range of other combination therapies. The favourable toxicity profile makes it an alternative 1st line regimen. [Table: see text]