Phase II Study of Irinotecan Plus Panitumumab as Second-Line Therapy for Patients with Advanced Esophageal Adenocarcinoma

Background. Esophageal adenocarcinoma (EAC) is a lethal cancer with increasing incidence. Panitumumab (Pa) is a fully humanized IgG2 monoclonal antibody against human EGFR. Cetuximab (Cx) combined with irinotecan (Ir) is active for second-line treatment of colorectal cancer. This phase II study was designed to evaluate Pa plus Ir as second-line therapy for advanced EAC. Methods. The primary endpoint was response rate (RR). Patients with one prior treatment were given Pa 9 mg/m(2) on day 1 and Ir 125 mg/m(2) on days 1 and 8 of each 21-day cycle. Inclusion criteria were confirmed EAC, measurable disease, no prior Ir or Pa, performance status < 2, and normal organ function. Results. Twenty-four patients were enrolled; 18 were eligible and evaluable. These patients were all white, with a median age of 62.5 years (range, 33-79 years), and included 15 men and 3 women. The median number of cycles was 3.5. The most common grade 1-2 adverse events were fatigue, diarrhea, anemia, leukopenia, and hypoalbuminemia. Grade 3-4 adverse events included hematologic, gastrointestinal, electrolyte, rash, fatigue, and weight loss. The median follow-up was 7.2 months (range, 2.3-14 months). There were no complete remissions. The partial response rate was 6% (1/18; 95% confidence interval [CI], 0.01-0.26). The clinical benefit (partial response [PR] plus stable disease [SD]) rate was 50%. The median overall survival was 7.2 months (95% CI, 4.1-8.9) with an 11.1% 1-year survival rate. The median progression-free survival was 2.9 months (95% CI, 1.6-5.3). Conclusion. Irinotecan and panitumumab as second-line treatment for advanced EAC are not active.