RATIONALE: Monoclonal antibodies can find and locate tumor cells and either kill them or
deliver tumor-killing substances to them without harming normal cells. Drugs used in
chemotherapy use different ways to stop tumor cells from dividing so they stop growing or
die. Combining more than one drug and combining chemotherapy with monoclonal antibody
therapy may kill more tumor cells.
PURPOSE: Phase I trial to study the effectiveness of monoclonal antibody therapy plus
combination chemotherapy in treating patients with advanced colorectal cancer.
OBJECTIVES: I. Define toxicity and the maximum tolerated dose of humanized monoclonal
antibody A33 (MOAB A33) when combined with carmustine, fluorouracil, vincristine, and
streptozocin in patients with advanced colorectal cancer. II. Determine the effect of
chemotherapy on human antihuman antibody response and on the pharmacokinetics of humanized
MOAB A33 in these patients. III. Define the humanized MOAB A33 dose for a phase II study.
OUTLINE: This is a dose escalation study of humanized monoclonal antibody A33 (MOAB A33).
Patients receive humanized MOAB A33 IV once a week for 14 weeks. Chemotherapy begins on day
29 and consists of carmustine IV on days 29-33, fluorouracil IV on days 29-33 and 64-68,
vincristine IV on days 29 and 64, and streptozocin IV every 7 days, beginning on day 29, for
10 doses. Courses repeat every 14 weeks in the absence of disease progression or
unacceptable toxicity. Cohorts of 3-6 patients receive escalating doses of humanized MOAB
A33. The maximum tolerated dose is defined as the dose at which no more than 2 of 6 patients
experience dose limiting toxicity.
PROJECTED ACCRUAL: There will be 3-18 patients accrued into this study over 2-9 months.
DISEASE CHARACTERISTICS: Histologically confirmed unresectable stage IV colon or rectal
cancer that has failed conventional chemotherapy for advanced disease or refused other
treatment Measurable disease No liver involvement of greater than 50% No clinical evidence
of CNS tumor involvement
PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 80-100% Life
expectancy: At least 14 weeks Hematopoietic: WBC at least 3,5000/mm3 Platelet count at
least 150,000/mm3 Hepatic: Bilirubin no greater than 1.0 mg/dL Renal: Creatinine no
greater than 1.5 mg/dL Cardiovascular: No clinically significant cardiac disease (New York
Heart Association class III/IV heart disease) Other: No positive human antimouse antibody
titer No serious infection requiring treatment with antibiotics No other serious illness
Not pregnant or nursing Effective contraception required of all fertile patients
PRIOR CONCURRENT THERAPY: Biologic therapy: No prior mouse monoclonal antibody or antibody
fragment, or chimeric or humanized antibody At least 4 weeks since prior immunotherapy
Chemotherapy: No prior carmustine, fluorouracil, vincristine, and streptozocin At least 4
weeks since prior chemotherapy Endocrine therapy: Not specified Radiotherapy: At least 4
weeks since prior radiotherapy Surgery: Not specified