RATIONALE: LMB-9 immunotoxin can locate tumor cells and kill them without harming normal cells. This may be an effective treatment for advanced pancreatic, esophageal, stomach, colon or rectal cancer.

PURPOSE: Phase I trial to study the effectiveness of LMB-9 immunotoxin in treating patients who have advanced pancreatic, esophageal, stomach, colon, or rectal cancer.

OBJECTIVES:

• Determine the toxicity of LMB-9 immunotoxin in patients with advanced adenocarcinoma of the colon, rectum, pancreas, esophagus, or stomach with overexpression of the Lewis-Y antigen.
• Determine the maximum tolerated dose of this drug in these patients.
• Determine the clinical response of patients treated with this drug.
• Determine the pharmacokinetics of this drug in these patients.

OUTLINE: This is a dose-escalation study.

Patients receive LMB-9 immunotoxin IV continuously on days 1-5. Patients with stable or responding disease after completion of the first course receive additional courses every 4-5 weeks in the absence of disease progression or unacceptable toxicity.

Cohorts of 3-6 patients receive escalating doses of LMB-9 immunotoxin until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which at least 2 of 3 or 2 of 6 patients experience dose-limiting toxicity.

Patients are followed at 3 weeks and then every 2 months thereafter.

PROJECTED ACCRUAL: A total of 40-50 patients will be accrued for this study within 1-2 years.

DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed advanced adenocarcinoma of the colon, rectum, pancreas, esophagus, or stomach that is refractory to standard treatment
• Overexpression of the Lewis-Y antigen
• Measurable or evaluable disease
• No CNS metastasis
• Metastatic liver disease from primary tumor allowed

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• ECOG 0-1

Life expectancy:

• At least 3 months

Hematopoietic:

• Platelet count greater than 100,000/mm^3
• Absolute granulocyte count greater than 1,200/mm^3

Hepatic:

• Bilirubin normal
• SGOT and SGPT no greater than 1.5 times upper limit of normal
• Hepatitis B or C antigen negative
• No liver disease (e.g., alcohol liver disease)
• Albumin at least 3.0 g/dL

Renal:

• Creatinine no greater than 1.4 mg/dL
• Creatinine clearance at least 60 mL/min
• Proteinuria no greater than 1 g/24 hours (grade II toxicity-like)

Cardiovascular:

• No prior coronary artery disease
• No New York Heart Association class II, III, or IV congestive heart failure
• No arrhythmia requiring treatment

Pulmonary:

• FEV_1 and FVC greater than 65% predicted

Other:

• No other concurrent malignancy
• No active peptic ulcer disease
• No known allergy to omeprazole
• No known seizure disorder
• No concurrent medical or psychiatric condition that would preclude study participation
• No contraindication to pressor therapy
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• At least 3 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin) and recovered

Endocrine therapy:

• At least 3 weeks since prior hormonal therapy

Radiotherapy:

• At least 3 weeks since prior radiotherapy and recovered

Surgery:

• Not specified