Name of the Trial
Phase I Study of Humanized Monoclonal Antibody MiK-beta-1 in Patients with T-Cell Large Granular Lymphocyte Leukemia (NCI-04-C0089). See the protocol summary at http://cancer.gov/clinicaltrials/NCI-04-C-0089.

Principal Investigator
Dr. John C. Morris, NCI CCR

Why Is This Trial Important?
T-cell large granular lymphocyte leukemia (T-LGLL) is a rare form of chronic leukemia characterized by the abnormal proliferation of white blood cells that contain packets (granules) of toxic enzymes and can destroy cells they recognize as foreign. T-LGLL usually develops in older adults and often follows a slowly progressive (indolent) course that may not require treatment if patients remain symptom free.

However, approximately one half of patients develop complications from T-LGLL that can be life-threatening. Some complications, such as increased susceptibility to infection, anemia, and impaired blood clotting, result from abnormally low numbers of normal white or red blood cells or platelets. Other complications, such as rheumatoid arthritis, result from disturbances in the immune system that cause autoimmune disorders.

Researchers have created a humanized monoclonal antibody, MiK-beta-1, that targets a protein located on the surface of malignant T lymphocytes that is crucial to their continued proliferation. This protein acts as a receptor molecule for interleukin 15, a cytokine that stimulates T-LGLL cell growth. Treatment with MiK-beta-1 may slow or interrupt the abnormal proliferation of T-LGLL cells by blocking the binding of IL-15 to its receptor, perhaps inhibiting disease progression and reducing the severity of some complications.

"This study is designed principally to assess the safety of a single dose of this monoclonal antibody," said Dr. Morris. "If the treatment is tolerated, we hope eventually to use repeated doses of MiK-beta-1 to treat not only T-LGLL, but also certain autoimmune disorders such as rheumatoid arthritis and multiple sclerosis."

Who Can Join This Trial?
Researchers plan to recruit up to 18 patients aged 18 and over with T-LGLL. See the complete list of eligibility criteria at http://www.cancer.gov/clinicaltrials/NCI-04-C-0089.

Where Is This Trial Taking Place?
The study is taking place at the NIH Clinical Center in Bethesda, Md.

Contact Information
For more information, contact the NCI Clinical Studies Support Center at 1-888-NCI-1937. The toll-free call is confidential.