Name of the Trial
Phase II Study of LMB-2 Immunotoxin in Patients with CD25-Positive Cutaneous T-Cell Lymphoma (NCI-04-C-0142). See the protocol summary at http://cancer.gov/clinicaltrials/NCI-04-C-0142.

Principal Investigator
Dr. Robert J. Kreitman, NCI CCR

Why This Trial Is Important
Cutaneous T-cell lymphoma (CTCL) is a type of non-Hodgkin lymphoma that includes mycosis fungoides and Sézary syndrome. CTCL is caused when cancerous T lymphocytes (or T cells) migrate out of blood vessels and invade the skin, where they give rise to a variety of abnormalities, including thickened skin plaques, reddening, and at more advanced stages, malignant tumors. In the most advanced stages, cancerous T cells spread into the lymphatic system and internal organs. CTCL is highly treatable when diagnosed at its earliest stages, but there is no curative treatment available for advanced disease.

Researchers are testing the effectiveness of an immunotoxin called LMB-2 in killing CTCL cells. LMB-2 is a laboratory-created monoclonal antibody fragment attached to a bacterial toxin. It binds to a protein called CD25, which is found on the surface of many human lymphocytes. CD25 is also present on CTCL cells in approximately half of all cases, where it appears more abundantly than on normal lymphocytes. The greater abundance of CD25 allows LMB-2 to target malignant T lymphocytes with great specificity. Once LMB-2 binds to CD25 on the cell surface, the toxin is taken up by the lymphocytes, causing them to die.

Patients will receive up to 6 courses of LMB-2 over approximately 6 months, providing their disease does not progress. Patients who respond completely to LMB-2 may receive further treatment.

"In a phase I trial of LMB-2 that involved patients with a variety of hematologic malignancies," said Dr. Kreitman, "the only patient with CTCL had a clinically significant partial response lasting more than 6 months."

Who Can Join This Trial
Researchers will enroll 16 to 27 patients aged 18 and older and diagnosed with advanced-stage CD25-positive CTCL. See the complete list of eligibility criteria at http://cancer.gov/clinicaltrials/NCI-04-C-0142.

Study Site and Contact Information
The trial is taking place at the NIH Clinical Center in Bethesda, Md. For more information, contact the NCI Clinical Studies Support Center at 1-888-NCI-1937. The toll-free call is confidential.