PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: Not specified Hematopoietic: WBC at least 3,000/mm3 Platelet count at least 100,000/mm3 No hemorrhagic events within the past 6 months Hepatic: Bilirubin normal SGOT normal INR no greater than 1.5 Renal: Creatinine no greater than 1.5 times upper limit of normal Cardiovascular: No thromboembolic events within the past 6 months Pulmonary: No evidence of pneumonia Other: No known hypersensitivity to recombinant humanized murine monoclonal antibodies No evidence of significant active infection (e.g., peritonitis or wound abscess) Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception