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