The use of the therapy, a drug known as rituximab, grew out of recent discoveries about the human immune system and the interactions between transplanted cells and recipients' own tissue. In the new study, posted on the website of the journal Blood (www.bloodjournal.org), researchers found that rituximab reduced the severity of chronic GVHD in 70 percent of the study participants who completed at least one course of treatment, including two who experienced complete remissions of symptoms. The benefits, which continued up to a year after therapy, occurred mainly in patients whose skin and musculoskeletal systems were affected by chronic GVHD.

"Our findings validate the preliminary work about the benefits of rituximab for this group of patients," says the study's lead author, Corey Cutler, MD, MPH, of Dana-Farber. "It offers a new line of therapy for individuals for whom, until now, few good options have existed."

Chronic graft-versus-host disease is the most common cause of disease and death among long-term survivors of donor stem-cell transplants for certain forms of cancer and blood diseases, affecting 60-70 percent of long-term survivors. It occurs when immune system cells in transplanted tissue launch an attack on recipients' own tissue, producing problems that can range from a mild rash to diarrhea and fever to life-threatening disorders. Despite therapy that can last months or years, chronic GVHD kills up to a third of all those who survive long-term after stem-cell transplants for leukemia.

Traditionally, scientists have thought that GVHD is caused by T cells, immune system cells whose job is to attack foreign tissue and
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Contact: Teresa Herbert
teresa_herbert@dfci.harvard.edu
617-632-5653
Dana-Farber Cancer Institute
23-Mar-2006