Anti-Tac(Fv)-PE38 (LMB-2) to Treat Chronic Lymphocytic Leukemia
Status:
Completed
Trial end date:
2011-12-31
Target enrollment:
Participant gender:
Summary
This study will evaluate the effectiveness of an experimental drug called LMB-2 for treating
chronic lymphocytic leukemia (CLL) 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 cancer cells
with CD25 on their surface, and a toxin produced by bacteria that kills the cancer cells to
which it binds. LMB-2 has killed CD 25-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 CLL who have CD25 receptor proteins on their cancer
cells and whose disease has progressed within 2 years of treatment with fludarabine 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, and a bone marrow biopsy.
Participants receive up to six cycles of LMB-2 therapy. 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. Patients are admitted to
the National Institutes of Health (NIH) Clinical Center for the first treatment cycle. If the
infusion is well tolerated, subsequent cycles may be given on an outpatient basis. 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 physical examination, blood tests, chest x-ray,
and EKG before each treatment cycle and at follow-up visits. With the patient's
permission, CT scans, echocardiogram, and bone marrow biopsies may be repeated before
some treatment cycles if these tests prove useful in evaluating the disease response to
LMB-2.
Patients may receive up to six cycles of LMB-2 as long as their cancer does not worsen and
they do not develop serious side effects. At the end of the treatment cycles, patients will
have blood tests done weekly by their local physician, and the results will be sent to the
NCI study investigators.