Study of PXD101 Alone and in Combination With 5-Fluorouracil (5-FU) in Patients With Advanced Solid Tumors

Inclusion Criteria: * Histologically confirmed solid tumors * Advanced colorectal cancer or other adenocarcinomas * Tumor progression after standard chemotherapy, or where none yet approved * At least one unidimensionally measurable lesion * Karnofsky performance \>= 70% * Life expectancy of at least 3 months * Age \>= 18 years * Signed, written Institutional Review Board (IRB)-approved informed consent * Acceptable liver function: * Bilirubin \<= 1.5 x upper limit of normal (ULN) * AST (SGOT) and ALT (SGPT) \<= 2.5 x ULN, OR * AST (SGOT) and ALT (SGPT) \<= 5 x ULN if liver metastasis * Acceptable renal function: * Serum creatinine within normal limits, OR * Calculated creatinine clearance of \>= 60 mL/min/1.73 m2 for certain patients * Acceptable hematologic status: * Absolute neutrophil count (ANC) \>= 1500 cells/mm3 * Platelet count \>= 100,000 (plt/mm3) * Hemoglobin \>= 9 g/dL * Urinalysis: No clinically significant abnormalities * Acceptable coagulation status: * Prothrombin time (PT)/partial thromboplastin time (PTT) within normal limits, OR * For patients on anticoagulation therapy, status within therapeutic range * For men and women of child-producing potential, use of effective contraception * Tumors accessible for needle biopsy Exclusion Criteria: * Significant cardiovascular disease. * A marked baseline prolongation of QT/QTc interval * Long QT syndrome * Required use of medication on dosing days that may cause torsade de pointes. * Infections requiring intravenous (IV) systemic therapy * Pregnant or nursing women * Treatment with chemotherapy or investigational therapy \< 4 weeks (28 days) prior to study entry (6 weeks for nitrosoureas, mitomycin C, or Avastin). * Treatment with radiation therapy or surgery either within 2 weeks prior to study entry, or not yet recovered if 2-4 weeks prior to study entry. * Unwillingness or inability to comply with protocol procedures. * Known active uncontrolled infection with HIV, hepatitis B, or hepatitis C * Serious nonmalignant disease (e.g. hydronephrosis, liver failure, or other conditions) that could compromise protocol objectives in the opinion of the investigator and/or the sponsor * Concurrent use of other investigational agent(s) * Serious concurrent medical illness