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

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00074048
Recruitment Status : Completed
First Posted : December 11, 2003
Last Update Posted : June 22, 2010
Information provided by:
MedImmune LLC

Brief Summary:

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.

Condition or disease Intervention/treatment Phase
Leukemia Drug: BL22 Phase 2

Detailed Description:



  • Determine the response rate in patients with cladribine-resistant hairy cell leukemia treated with BL22 immunotoxin.


  • 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.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 36 participants
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Phase II Trial Of BL22 Immunotoxin In Hairy Cell Leukemia
Study Start Date : October 2003
Actual Primary Completion Date : April 2007
Actual Study Completion Date : July 2008

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Leukemia

Arm Intervention/treatment
Experimental: 1
BL22 immunotoxin
Drug: BL22
Dosing via IV on Days 1,3, and 5.

Primary Outcome Measures :
  1. Response rate [ Time Frame: After even cycle numbers (2,4,6,8,10) ]

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

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No


  • 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



  • 18 and over

Performance status

  • ECOG 0-2

Life expectancy

  • Not specified


  • See Disease Characteristics


  • 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


  • Creatinine no greater than 1.4 mg/dL OR
  • Creatinine clearance at least 50 mL/min


  • No symptomatic congestive heart failure
  • No unstable angina pectoris
  • No cardiac arrhythmia


  • 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


Biologic therapy

  • No prior BL22 immunotoxin
  • More than 12 weeks since prior monoclonal antibody therapy


  • 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)


  • Not specified


  • Not specified


  • No other concurrent investigational agents

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00074048

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United States, Maryland
Warren Grant Magnuson Clinical Center - NCI Clinical Trials Referral Office
Bethesda, Maryland, United States, 20892-1182
Sponsors and Collaborators
MedImmune LLC
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Study Chair: Robert Kreitman, MD National Cancer Institute (NCI)
Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: Radhika Parikh, MedImmune Inc. Identifier: NCT00074048    
Obsolete Identifiers: NCT00071318
Other Study ID Numbers: CDR0000341680
First Posted: December 11, 2003    Key Record Dates
Last Update Posted: June 22, 2010
Last Verified: June 2010
Keywords provided by MedImmune LLC:
refractory hairy cell leukemia
Additional relevant MeSH terms:
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Leukemia, Hairy Cell
Neoplasms by Histologic Type
Lymphoproliferative Disorders
Lymphatic Diseases
Immunoproliferative Disorders
Immune System Diseases