Common virus becomes a new target for cancer treatment

A typically innocuous virus found in 90 percent of people worldwide is the key to a new treatment for a cancer particularly common in North Africa and Southeast Asia. A new study showing that antigens produced by the Epstein Barr virus may provide an ideal target for therapy will be published in the March 1, 2005, issue of Blood, the official journal of the American Society of Hematology.

Ten patients diagnosed with advanced nasopharyngeal carcinoma took part in the study – these patients also tested positive for the Epstein Barr virus, a member of the herpes family responsible for the “kissing disease” (mononucleosis) and commonly associated with this cancer’s tumors.

Patients were given intravenous doses of specialized T cells that specifically targeted antigens produced by the Epstein Barr virus. Developed by researchers from the Center for Cell and Gene Therapy at Baylor College of Medicine, Methodist Hospital in Houston, and Texas Children’s Hospital, these T cells were created using the patient’s own blood to recognize the antigens and destroy the cancerous cells harboring the virus. The treatment was well tolerated in all but one patient, who had pre-existing facial swelling that increased after the infusion.

“Radiation and chemotherapy, the traditional treatments for nasopharyngeal carcinoma, frequently fail and can cause severe long-term side effects,” said senior study author Helen Heslop, M.D., Professor of Medicine and Pediatrics at Baylor College of Medicine. “There is a compelling need for therapies that can improve disease-free survival without severe toxicity. This study demonstrates that virus-specific T cells show remarkable activity in some patients with this cancer and this may lead to new treatments for nasopharyngeal carcinoma.”

A majority of the patients (six) remain completely disease-free one to two years after the treatment. Two patients had no response to the treatment. One patient’s cancer progressed after the infusion, which required the addition of chemotherapy. However, the patient experienced a partial remission, whereas previous chemotherapy treatments alone had had no effect. The tenth patient’s disease did not better or worsen, but remained stable after treatment.

“This very important work combines the use of a novel target – the antigen produced by the Epstein Barr virus – with the use of cells directed at that protein,” notes Donald M. Miller, M.D., Ph.D., Director of the James Graham Brown Cancer Center in Louisville, Kentucky. “The authors provide considerable hope that this approach will realize the important potential of cell-based therapies.”