Afatinib Dimaleate and Capecitabine in Treating Patients With Advanced Refractory Solid Tumors, Pancreatic Cancer or Biliary Cancer

PRIMARY OBJECTIVES: I. Evaluate the safety, maximum tolerated dose (MTD), and the recommended phase II dose (RP2D) of afatinib dimaleate (afatinib) in combination with capecitabine in patients with advanced solid tumors (phase I) and pancreatico-biliary cancers (phase Ib). (Phase I/Ib) SECONDARY OBJECTIVES: I. Evaluate biomarkers of response from tumor biopsies, including markers related to the epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) pathways via OncoPlex or other equivalent gene sequencing assay. (Phase I/Ib) II. Evaluate rates of response and stable disease, duration of response, time to progression, progression-free and overall survival. (Phase I/Ib) OUTLINE: This is a phase I, dose-escalation study of afatinib dimaleate followed by a phase Ib study. Patients receive afatinib dimaleate orally (PO) once daily (QD) on days 1-21 and capecitabine PO twice daily (BID) on days 1-14. Courses repeat every 21 days in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up every 3 months for 3 years.