Phase II trial to study the effectiveness of imatinib mesylate in treating patients who have stage IV colorectal cancer. Imatinib mesylate may interfere with the growth of tumor cells by blocking certain enzymes necessary for cancer cell growth

PRIMARY OBJECTIVES:

I. To determine response to Gleevec (Imatinib Mesylate) in patients with metastatic colorectal cancer and with c-Kit, Arg, Abl, or PDGF-R expression.

II. To determine the side effects of Imatinib Mesylate in patients with colorectal cancer.

III. To study the biologic effects of Imatinib Mesylate on the c-Kit and PDGF-R system and downstream signaling in metastatic colorectal cancer.

OUTLINE:

Patients receive oral imatinib mesylate twice daily. Treatment continues for 8 weeks in the absence of disease progression or unacceptable toxicity. Patients with stable disease or better continue therapy until disease progression or 1 year after complete response.

Inclusion Criteria:

• Histologically confirmed stage IV colorectal cancer

• Arg, KIT (CD117), or PDGF-R expression (1+ in 20% of cells) in the tumor or microvasculature

• At least one unidimensionally measurable lesion

  • At least 10 mm by spiral CT scan

• No known brain metastases

• Performance status - ECOG 0-2

• Performance status - Karnofsky 60-100%

• At least 12 weeks

• Granulocyte count at least 1,500/mm^3

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

• Bilirubin no greater than 2.0 mg/dL

• AST/ALT less than 2.5 times upper limit of normal

• Creatinine no greater than 2.0 mg/mL

• No symptomatic congestive heart failure

• No unstable angina pectoris

• No cardiac arrhythmia

• Not pregnant or nursing

• Negative pregnancy test

• Fertile patients must use effective barrier contraception during and for 3 months after study participation

• No other malignancy within the past 3 years except non-melanoma skin cancer or carcinoma in situ of the cervix

• No concurrent uncontrolled illness

• No ongoing or active infection

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

• More than 4 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin) and recovered

• More than 4 weeks since prior radiotherapy and recovered

• More than 3 weeks since prior surgery (excluding diagnostic biopsy)

• No other concurrent investigational agents

• No concurrent therapeutic doses of anticoagulants (e.g., warfarin)

• No concurrent grapefruit

• No concurrent combination antiretroviral therapy for HIV-positive patients