A Study of PEP503(Radio-enhancer) With Radiotherapy and Chemotherapy for Patients With Rectal Cancer

Inclusion Criteria * Histologically proven adenocarcinoma of the rectum which is T3-4, N any, or locally unresectable disease , without evidence of distant metastases (M0) * Distant border of the tumor must be located ≤ 10 cm from the anal verge * Staging with MRI, transrectal ultrasound or CT-scan to confirm stage and resectability * ECOG performance 0 - 1 * Age: 20 - 80 years old * Adequate bone marrow, renal, and hepatic function as: * absolute neutrophil count (ANC) ≥ 1,500/mm3 * platelet count ≥ 100,000/mm3 * total bilirubin ≤ 1.5x the upper limit of normal (ULN) * aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤ 2.5x ULN * alkaline phosphatase (ALP) ≤ 2.5 x ULN * calculated creatinine clearance ≥ 50 mL/min, or creatinine within normal range * All female patients of childbearing potential must have negative urine pregnancy test within the 7 days prior study treatment with PEP503. Patients must agree to use effective contraception during the study Exclusion Criteria: * Prior history of pelvic radiation therapy * Hypersensitivity to fluoropyrimidine * Uncontrolled serious medical or psychiatric illness * Myocardial infarction or uncontrolled angor pectoris (angina) within the prior 6 months * No more than 4 weeks since prior participation in any investigational drug study * Major surgery within 28 days * Other malignancy within the past 3 years except effectively treated squamous cell or basal cell skin cancer, melanoma in situ, carcinoma in situ of the cervix, or carcinoma in situ of the colon or rectum * Cardiovascular disease that would preclude study treatment or follow-up * Informed consent not duly signed and dated to participate in the study