Immunotoxin Therapy in Treating Patients With Hairy Cell Leukemia

DISEASE CHARACTERISTICS:

* Histologically confirmed refractory or recurrent hairy cell leukemia

  * Relapsed after less than 2 years of complete remission after purine analog therapy
  * Must have at least one of the following indications for therapy:

    * Progressive or massive splenomegaly
    * Cytopenia defined by the following:

      * Absolute neutrophil count less than 1,000/mm\^3 OR
      * Platelet count less than 100,000/mm\^3 OR
      * Hemoglobin less than 12 g/dL
    * More than 20,000 hairy cells/mm\^3
    * Symptomatic adenopathy
    * Constitutional symptoms including tumor-related fever or bone pain
* Evidence of CD22 positivity by 1 of the following:

  * More than 15% of malignant cells from a site must react with anti-CD22 by immunohistochemistry
  * More than 30% of malignant cells from a site CD22+ by fluorescent-activated cell sorter
  * More than 400 CD22 sites/cell (average) on malignant cells as assessed by radiolabeled anti-CD22 binding
* No CNS disease requiring treatment
* No patients whose serum neutralizes BL22 immunotoxin in tissue culture, due to either antitoxin or antimouse-IgG antibodies

  * No patients whose serum neutralizes more than 75% of the activity of 1 microgram/mL of BL22 immunotoxin

PATIENT CHARACTERISTICS:

Age:

* 18 and over

Performance status:

* Karnofsky 60-100%

Life expectancy:

* More than 6 months

Hematopoietic:

* See Disease Characteristics
* Pancytopenia due to disease allowed

Hepatic:

* ALT and AST less than 2.5 times upper limit of normal (ULN)
* Bilirubin less than 1.5 times ULN

Renal:

* Creatinine no greater than 2.0 mg/dL

Pulmonary:

* FEV1 at least 60% of predicted
* DLCO at least 55% of predicted

Other:

* HIV negative
* Not pregnant or nursing
* Negative pregnancy test
* Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

* Prior bone marrow transplantation allowed
* At least 3 weeks since prior interferon for the malignancy
* More than 3 months since prior monoclonal antibody therapy (e.g., rituximab)

Chemotherapy:

* See Disease Characteristics
* At least 3 weeks since prior cytotoxic chemotherapy for the malignancy

Endocrine therapy:

* Not specified

Radiotherapy:

* At least 3 weeks since prior whole body electron beam radiotherapy for the malignancy
* Radiotherapy within the past 3 weeks allowed provided less than 10% of total bone marrow was treated and patient has measurable disease outside the radiation port

Surgery:

* Not specified

Other:

* At least 3 weeks since prior retinoids for the malignancy
* At least 3 weeks since any other prior systemic therapy for the malignancy
* No concurrent therapeutic warfarin