BL22 Immunotoxin in Treating Patients Previously Treated With Cladribine for Hairy Cell Leukemia

Inclusion Criteria

• •DISEASE CHARACTERISTICS:
• •Histologically confirmed hairy cell leukemia
• •CD22-positive disease by fluorescence-activated cell sorting with anti-CD22 antibody
• •Meets at least 1 of the following indications for treatment:
• •* Absolute neutrophil count less than 1,000/mm\^3
• •* Hemoglobin less than 10 g/dL
• •* Platelet count less than 100,000/mm\^3
• •* Absolute lymphocyte count greater than 20,000/mm\^3
• •* Symptomatic splenomegaly
• •Meets 1 of the following response criteria:
• •* No response
• •* Complete response (CR) or partial response (PR) less than 2 years in duration after the last course of prior cladribine
• •* CR or PR less than 4 years in duration after a second or later course of prior cladribine
• •PATIENT CHARACTERISTICS:
• •Age
• •18 and over
• •Performance status
• •ECOG 0-2
• •Life expectancy
• •Not specified
• •Hematopoietic
• •See Disease Characteristics
• •Hepatic
• •AST and ALT no greater than 2.5 times upper limit of normal (ULN)
• •Bilirubin no greater than 2.2 mg/dL
• •Albumin at least 3.0 g/dL
• •Renal
• •Creatinine no greater than 1.4 mg/dL OR
• •Creatinine clearance at least 50 mL/min
• •Cardiovascular
• •No symptomatic congestive heart failure
• •No unstable angina pectoris
• •No cardiac arrhythmia
• •Other
• •Not pregnant or nursing
• •Negative pregnancy test
• •Fertile patients must use effective contraception
• •No serum that neutralizes more than 75% of the activity of 1 µg/mL of BL22 immunotoxin using a bioassay
• •No ongoing or active infection
• •No psychiatric illness or social situation that would preclude study compliance
• •No other concurrent uncontrolled illness that would preclude study participation
• •Understand and give informed consent
• •PRIOR CONCURRENT THERAPY:
• •Biologic therapy
• •No prior BL22 immunotoxin
• •More than 12 weeks since prior monoclonal antibody therapy
• •Chemotherapy
• •See Disease Characteristics
• •More than 4 weeks since prior systemic cytotoxic chemotherapy
• •Endocrine therapy
• •More than 4 weeks since prior systemic steroids (except stable doses of prednisone no greater than 20 mg/day)
• •Radiotherapy
• •Not specified
• •Surgery
• •Not specified
• •Other
• •No other concurrent investigational agents