A pilot study of edrecolomab (Panorex, 17-1A antibody) and capecitabine in patients with advanced or metastatic adenocarcinoma

Edrecolomab (Panorex®) is a monoclonal antibody directed against the 17-1A antigen located on the cell surfaces of carcinomas. Clinical activity has been seen in colon and breast cancer. This trial investigated the feasibility of combining edrecolomab with the oral fluoropyrimidine capecitabine (Xeloda®). Patients received a loading dose of edrecolomab 500 mg intravenously (IV) on day-14, followed 2 weeks later by 100 mg IV every 28 days (day 1). Capecitabine was administered to single-patient cohorts at escalating doses of 1500, 2000, and 2500 mg/m²/day in two equally divided doses for 14 of 21 days, beginning on day 1. Additional patients were enrolled at the 2500 mg/m²/day dose level to better define the toxicities of combination therapy. Toxicity assessment was the primary endpoint. Twenty seven patients with advanced or metastatic adenocarcinoma were enrolled on this study: 20 were evaluable for toxicity and 18 for response. The most common toxicities were elevated liver enzymes, diarrhea, and hand-foot syndrome. In cycle 1, grade 3 hand-foot syndrome was seen in two patients, and grade 3 diarrhea in one patient. Grade 2 toxicities included diarrhea, hand-foot syndrome, anemia, leukopenia, and transaminitis. Cumulative hand-foot syndrome was observed in four patients treated beyond two cycles. Three patients had edrecolomab infusion reactions during the course of treatment. One complete response and two partial responses were seen. Nine patients had disease stabilization lasting a median of 17.5 weeks (range 14.5-28+). Edrecolomab and capecitabine may be safely given in combination to patients with advanced or metastatic adenocarcinoma. Clinical activity is seen in this heavily pretreated patient population.