RATIONALE: Radiolabeled monoclonal antibodies can locate tumor cells and deliver tumor-killing substances to them without harming normal cells. Radiolabeled monoclonal antibody therapy may be effective treatment for colorectal cancer.

PURPOSE: Phase I trial to study the effectiveness of radiolabeled monoclonal antibody therapy in treating patients who have recurrent or persistent metastatic colorectal cancer.

OBJECTIVES:

• Determine the maximum tolerated dose of iodine I 131 monoclonal antibody CC49-deltaCH2 (deleted CH2 region) in patients with colorectal cancer.
• Determine the toxic effects, plasma pharmacokinetics, whole body biodistribution, and conjugate stability of this drug in these patients.
• Determine the ability of this drug to localize to tumor sites in these patients.
• Determine the immune response in patients treated with this drug.

OUTLINE: This is a dose-escalation study.

Patients receive a tracer dose of iodine I 131 monoclonal antibody CC49-deltaCH2 IV on day 1 and a therapy dose over 30 minutes on day 8.

Cohorts of 3-5 patients receive escalating doses of iodine I 131 monoclonal antibody CC49-deltaCH2 until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose at which 3 of 5 patients experience grade 3 or greater toxicity while 0-2 of 5 patients experience reversible grade 4 hematologic toxicity.

Patients are followed weekly for a minimum of 7 weeks and then every 6 weeks until disease progression.

PROJECTED ACCRUAL: Approximately 3-15 patients will be accrued for this study.

DISEASE CHARACTERISTICS:

• Histologically confirmed metastatic adenocarcinoma of the colon or rectum

  • Not amenable to surgical resection
  • Recurrent or persistent disease after standard surgery, radiotherapy, and chemotherapy, including fluorouracil and irinotecan
• TAG-72 positive

PATIENT CHARACTERISTICS:

Age:

• 19 and over

Performance status:

• ECOG 0-2

Life expectancy:

• Not specified

Hematopoietic:

• WBC greater than 3,500/mm^3
• Platelet count greater than 125,000/mm^3
• Hemoglobin greater than 10 g/dL
• No nucleated RBC or significant teardrop RBC morphology

Hepatic:

• Bilirubin less than 1.5 mg/dL
• SGOT/SGPT less than 4 times normal
• Hepatitis B surface antigen negative

Renal:

• Creatinine less than 2.0 mg/dL

Other:

• HIV negative
• No other malignancy within the past 5 years except basal cell skin cancer
• No allergy to iodine
• No detectable antibody to monoclonal antibody CC49
• Not pregnant or nursing
• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• At least 3 weeks since prior immunotherapy and recovered
• No prior bone marrow or stem cell transplantation
• No other concurrent immunotherapy

Chemotherapy:

• See Disease Characteristics
• At least 3 weeks since prior chemotherapy and recovered
• No concurrent chemotherapy

Endocrine therapy:

• Not specified

Radiotherapy:

• See Disease Characteristics
• At least 3 weeks since prior radiotherapy and recovered
• No prior radiotherapy to more than 25% of red marrow
• No concurrent radiotherapy

Surgery:

• See Disease Characteristics
• At least 3 weeks since prior surgery and recovered