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

Study Overview
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Brief Summary
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RATIONALE: The BL22 immunotoxin can locate tumor cells and kill them without harming normal cells. This may be an effective treatment for hairy cell leukemia that has not responded to treatment with cladribine. PURPOSE: This phase II trial is studying BL22 immunotoxin to see how well it works in treating patients previously treated with cladribine for hairy cell leukemia.

Detailed Description
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OBJECTIVES: Primary Determine the response rate in patients with cladribine-resistant hairy cell leukemia treated with BL22 immunotoxin. Secondary Determine the response duration in patients treated with this drug. Determine the safety of this drug in these patients. Determine the pharmacokinetics of this drug in these patients. Correlate BL22 blood levels and toxicity of this drug with the development of neutralizing antibodies in these patients. OUTLINE: Patients receive BL22 immunotoxin IV over 30 minutes on days 1, 3, and 5 followed by rest. Patients are then evaluated at 8 weeks. Patients achieving complete hematologic remission are followed. All other patients continue to receive BL22 immunotoxin as above on days 1, 3, and 5. Treatment repeats every 4 weeks for up to a total of 16 courses in the absence of disease progression or unacceptable toxicity. Patients achieving CR without minimal residual disease (MRD) receive 2 courses beyond CR. Patients achieving CR with MRD receive 4 courses beyond CR. Patients are followed every 4 months for 1 year, every 6 months for 1 year, and then annually thereafter. PROJECTED ACCRUAL: A total of 36 patients will be accrued for this study within 3 years.

Official Title
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Phase II Trial Of BL22 Immunotoxin In Hairy Cell Leukemia

Conditions
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Leukemia

Intervention / Treatment
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* Drug: BL22


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 1<br>BL22 immunotoxin | Drug: BL22<br>* Dosing via IV on Days 1,3, and 5.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Response rate |  | After even cycle numbers (2,4,6,8,10) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Duration of Response: [Timeframe: Date that a response begins with the date that PD is documented.] |  | 30 days after last dose of study drug | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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refractory hairy cell leukemia