Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically or cytologically confirmed metastatic or recurrent colorectal
adenocarcinoma that has progressed during or within 6 months of
fluoropyrimidine-based therapy

- Prior treatment with irinotecan with or without fluorouracil

- Evaluable or measurable disease

- Uni-dimensionally measurable disease allowed provided CEA is at least 2 times
the upper limit of normal

- No meningeal or CNS metastases or carcinomatous meningitis

PATIENT CHARACTERISTICS:

Age:

- 18 and over

Performance status:

- Karnofsky 70-100%

Life expectancy:

- At least 3 months

Hematopoietic:

- WBC at least 3,000/mm^3

- Absolute neutrophil count at least 1,500/mm^3

- Platelet count at least 100,000/mm^3

Hepatic:

- Bilirubin less than 1.5 mg/dL (regardless of liver metastases)

- AST and ALT less than 1.5 times upper limit of normal (ULN) (3 times ULN if liver
metastases present)

- PT and INR normal

- PTT normal

Renal:

- Creatinine less than 1.5 mg/dL OR

- Creatinine clearance greater than 50 mL/min

Other:

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

- HIV negative

- No known hypersensitivity to NB1011 or any excipient or vehicle in its formulation

- No active or uncontrolled serious bacterial, viral, fungal, or parasitic infection

- No prior or concurrent alcohol abuse or dependency

- No other malignancy within the past 2 years except adequately treated basal cell or
squamous cell skin cancer or carcinoma in situ of the cervix

- No concurrent medical or psychological condition that would preclude study

PRIOR CONCURRENT THERAPY:

Biologic therapy:

- Not specified

Chemotherapy:

- See Disease Characteristics

- Recovered from prior anticancer chemotherapy

- No concurrent fluoropyrimidine-based or thymidylate synthase inhibitor agents

Endocrine therapy:

- Not specified

Radiotherapy:

- Recovered from prior anticancer radiotherapy

- No concurrent radiotherapy except palliative radiotherapy (to control a fracture or
pain) provided index lesions are not involved

Surgery:

- Recovered from prior anticancer surgery

Other:

- At least 30 days since prior investigational agents

- No other concurrent anticancer therapy

- No concurrent disulfiram