LMB-2

Background:
About 80% of patients with hairy cell leukemia (HCL) have tumor cells that have a protein on their surface called cluster of differentiation 25 (CD25).
The experimental drug LMB-2 is a recombinant immunotoxin that has been shown to kill leukemia and lymphoma cells with the CD25 protein. (A recombinant immunotoxin is a genetically engineered drug that has two parts - a protein that binds or targets a cancer cell, and a toxin that kills the cancer cell to which it binds.)
Objectives:
To evaluate the safety and effectiveness of LMB-2 in patients with HCL whose cancer cells contain the CD25 protein.
To evaluate the effects of LMB-2 on the immune system, determine how the drug is metabolized by the body and examine its side effects.
Eligibility:
-Adults with hairy cell leukemia whose tumor cells have CD25 on their surface
Design:
Up to 27 patients may be included in the study.
Patients receive an infusion of LMB-2 through a vein every other day for three doses (days 1, 3, 5), constituting one treatment cycle.
Patients may receive up to six treatment cycles every 4 weeks unless their cancer worsens or they develop unacceptable side effects.
Blood is drawn weekly for various tests.
Before each cycle and in follow-up visits, disease status is evaluated with a physical examination, blood tests, chest x-ray and electrocardiogram.
Before the first cycle, patients may have a computed tomography (CT) scan, echocardiogram (heart ultrasound test) and bone marrow biopsy. With the patient's permission, these tests may be repeated before other cycles also.

This study will evaluate the effectiveness of an experimental drug called LMB-2 for treating cutaneous T-cell lymphoma in patients who have a protein called cluster of differentiation 25 (CD25) on their cancer cells. LMB-2 is a recombinant immunotoxin. It is made up of two parts: a genetically engineered monoclonal antibody that binds to CD25, and a toxin produced by bacteria that kills the cancer cells to which it binds. LMB-2 has killed CD25-containing cells in laboratory experiments and has caused tumors in mice to shrink. Preliminary studies in humans have shown some effectiveness in shrinking tumors in patients with various types of lymph and blood cancers.
Patients 18 years of age and older with stage 1b to IV cutaneous T-cell lymphoma that has progressed within 2 years of systemic or topical therapy and who have CD25 receptor proteins on their cancer cells may be eligible for this study. Candidates are screened with a medical history and physical examination, blood and urine tests, electrocardiogram (EKG), echocardiogram, chest x-ray, computed tomography (CT) scans of the chest, abdomen and pelvis, skin punch biopsy to evaluate tumor infiltration in the skin, and a bone marrow biopsy on patients with stage IIa disease and higher. In addition, the patient's blood, bone marrow, tumor, or other tissue is tested to determine the presence of CD25 on cancer cells.
Participants receive up to nine cycles of LMB-2 therapy as long as their cancer does not worsen and they do not develop serious side effects. Each 28-day cycle consists of 30-minute infusions of LMB-2 on cycle days 1, 3, and 5. The drug is infused through an intravenous (IV) catheter (plastic tube placed in a vein) or a central venous line - an IV tube placed in a large vein in the neck or chest that leads to the heart. In addition to drug therapy, patients undergo the following procedures:
Blood draws: Blood is drawn before, during, and after each LMB-2 infusion to measure blood levels of the drug, evaluate its effects on the cancer cells, and monitor side effects. Blood tests are also done before and during each cycle to determine how the immune system is interacting with the drug.
Disease evaluations: Patients undergo a careful skin examination, blood tests, chest x-ray, and EKG before each treatment cycle and at follow-up visits. A CT scan and echocardiogram (heart ultrasound) are done before the first cycle. Before the first and second cycles, patients have a biopsy of the lymphoma on the skin. If the biopsy is helpful in evaluating the disease response to LMB-2, additional biopsies may be requested prior to other cycles as well. A nuclear medicine scan may be done, and a bone marrow biopsy may be done in patients with stage II to IV disease. If these tests are helpful in understanding the response of the lymphoma to treatment, they may also be repeated prior to other cycles, with the patient's permission.
Patients are admitted to the National Institutes of Health (NIH) Clinical Center for the first treatment cycle. Subsequent cycles are given as outpatients. If the infusions are well tolerated, patients may return home after about one week (or possibly longer if complications occur). After returning home, patients have blood tests done weekly by their local physicians.