Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically or cytologically confirmed metastatic or locally recurrent
adenocarcinoma of the colon or rectum

- No curable stage of disease

- At least 1 unidimensionally measurable lesion

- At 20 mm by conventional techniques OR at least 10 mm by spiral CT scan

- No tumor lesions in previously irradiated area except clearly measurable lesion
documented histologically to be consistent with recurrent tumor in previously
irradiated bed within pelvis

- The following are considered nonmeasurable disease:

- Bone lesions Leptomeningeal disease

- Ascites

- Pleural/pericardial effusion

- Inflammatory breast disease

- Lymphangitis cutis/pulmonis

- Abdominal masses not confirmed and followed by imaging techniques

- Cystic lesions

- No known brain metastases

PATIENT CHARACTERISTICS:

- Age: 18 and over

- Performance status: ECOG 0-2 OR Karnofsky 60-100%

- Life expectancy: More than 12 weeks

- WBC at least 3,000/mm3

- Absolute neutrophil count at least 1,500/mm3

- Platelet count at least 100,000/mm3

- Bilirubin normal

- AST/ALT no greater than 2.5 times upper limit of normal

- Creatinine normal OR creatinine clearance at least 60 mL/min

- No symptomatic congestive heart failure

- No unstable angina pectoris

- No cardiac arrhythmia

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception during and for 6 months after study

- Eligible for placement of a central venous catheter

- No prior allergic reactions attributed to compounds of similar chemical or biologic
composition to rebeccamycin analogue

- No other uncontrolled concurrent illness

- No ongoing or active infection

- No psychiatric illness or social situation that would preclude study compliance

PRIOR CONCURRENT THERAPY:

- No concurrent prophylactic growth factors (e.g., epoetin alfa) except for clinically
defined indication (e.g., filgrastim (G-CSF) for febrile neutropenia)

- At least 4 weeks since prior chemotherapy (e.g., fluorouracil, oral
fluoropyrimidines, irinotecan, or oxaliplatin) (6 weeks for nitrosoureas or
mitomycin)

- No other concurrent chemotherapy

- No concurrent hormones except for clinically defined indication

- At least 4 weeks since prior radiotherapy (including to bony sites, whole pelvis,
lung, liver, or spinal cord/brain) and recovered

- No prior total dose of radiotherapy more than 7,000 cGy

- No prior radiotherapy to 40% or more of total bone marrow

- No prior radiotherapy to only site of measurable disease

- No concurrent radiotherapy

- Recovered from prior therapy 1 prior adjuvant treatment allowed 1 prior treatment for
advanced disease allowed

- At least 4 weeks since prior investigational agents

- No other concurrent investigational antineoplastic drugs

- No other concurrent investigational agents

- No concurrent commercial agents for colorectal cancer

- No concurrent combination antiretroviral therapy for HIV-positive patients