This study proposes a single-arm, phase II study of irinotecan with panitumumab as second-line therapy for patients with advanced esophageal adenocarcinoma. Efficacy will be assessed by response rate, with an exploratory outcome endpoint of time to progression (as panitumumab may result in prolonged stable disease). In addition to the usual safety assessments, molecular correlates will be carried out in order to search for pharmacodynamic and pharmacogenomic features that may correlate with response. Measures of host/patient immune function will be assessed by evaluating the relationship between Fc receptor polymorphisms and response in patients treated with panitumumab. Measures of EGFR protein and phosphoprotein expression by immunohistochemical- (IHC-) staining, K-ras mutation status1 and reverse-phase protein arrays (RPPA) and EGFR gene amplification by fluorescence in situ hybridization (FISH) will be assessed as exploratory correlates.