A phase II study of capecitabine and oxaliplatin (CAPOX) in metastatic adenocarcinoma of the small bowel (SBA) or ampulla of Vater

14025 Background: Metastatic SBA and ampullary adenocarcinoma (AAC) are incurable, aggressive malignancies. Limited data exists regarding the role of systemic chemotherapy in these diseases. Given the marked activity of CAPOX in other cancers of the gastrointestinal tract, we have investigated the activity of this combination in these two tumor types. Methods: Patients (pts) with either metastatic or unresectable SBA and AAC who had adequate organ function, ECOG performance status (PS) ≤2 and measurable disease per modified RECIST criteria were enrolled. Prior use of 5-FU or capecitabine as adjuvant therapy, neoadjuvant therapy, or with radiation was allowed. CAPOX was administered as a 21 day cycle with oxaliplatin 130mg/m2 IV on day 1 and capecitabine 750mg/m2 PO BID days 1–14. Up to 30 pts will be enrolled. The primary endpoint is overall response rate (ORR). Results: Eleven pts have been enrolled from 11/04 to 12/05 (6 with AAC and 5 with SBA). Ten pts have received ≥2 cycles and are evaluable for response. All pts had metastatic disease and none had received prior chemotherapy. Patient (pt) characteristics: median age 59 (49–76); M/F (4/7); 91% PS 0–1. Grade 3/4 toxicities included fatigue (5), neuropathy (1), anorexia (1), thrombocytopenia (1), hypokalemia (1), hyponatremia (1), and musculoskeletal (1). Common grade 1/2 toxicities included neuropathy (8), nausea (8), diarrhea (6), and fatigue (5). Four pts required dose reduction and 1 pt discontinued due to toxicity (grade 3 fatigue). Six pts, 3 AAC and 3 SBA, responded with an ORR of 60% (95% CI 31 to 83%). Five responses have been confirmed and 1 AAC pt obtained a complete response after 5 cycles of treatment. Median time to progression was 6.8m (95% CI 4.4 to 9.3+m). Conclusions: The combination of CAPOX is both well-tolerated and highly active. The ORR of 60% is one of the highest yet reported in the literature for the treatment of adenocarcinoma of the small bowel and ampulla of Vater. Enrollment continues on this trial. (Supported by a research grant from Sanofi-Aventis). [Table: see text]