Home » Common virus may factor in tomorrow’s cancer treatment
May 2005 – Baylor College of Medicine From the Laboratories
By Ross Tomlin
A mostly harmless virus could play a vital role in the treatment of a certain form of throat cancer, according to researchers at the Center for Cell and Gene Therapy at Baylor College of Medicine, The Methodist Hospital and Texas Children’s Hospital.
Carried in 90 percent of all people, the Epstein-Barr virus produces antigens that may be targets for immunotherapy in patients with nasopharyngeal carcinoma, a form of throat cancer common in North Africa and Southeast Asia. The findings came from a study, funded by the National Institutes of Health, published in a recent edition of Blood, the official journal of the American Society of Hematology.
“The results of this study demonstrate that T-cells (immune-system cells), specific for this virus, have activity in some patients with this cancer,” said Helen Heslop, M.D., professor of medicine and pediatrics at BCM as well as senior study author. “We have had two patients who had multiple relapsed disease who failed all other therapy yet attained complete remission after getting the cells.”
In the study, patients with nasopharyngeal carcinoma were given intravenous doses of specialized T cells that specifically targeted antigens produced by the Epstein-Barr virus (EBV), a member of the herpes family responsible for mononucleosis and commonly associated with this cancer’s tumors. The T-cells were created using the patient’s own blood to recognize and destroy cancerous cells harboring the virus. Unlike a vaccine which stimulates a person’s own immune response, Heslop and her colleagues removed patients’ T-cells, stimulated them with EBV-infected B-cells at the Good Manufacturing Practice Laboratories of the Center for Cell and Gene Therapy (CAGT) within The Feigin Center at Texas Children’s Hospital, and injected them back into the patients.
Ten patients diagnosed with advanced nasopharyngeal carcinoma took part in the study. All tested positive for the Epstein-Barr virus. The treatment was well tolerated in all but one patient, who had a pre-existing facial swelling that increased after the infusion.
Six patients remain completely disease-free one to two years after the treatment. Two patients showed no response to the treatment. One patient’s cancer progressed after the infusion. After the addition of chemotherapy, the patient experienced a partial remission. (Previous chemotherapy treatments alone had had no effect). The tenth patient’s disease remained stable after treatment and showed no improvement or decline.
Heslop said the researchers sought to find a less toxic alternative to current cancer treatments.
“There was a compelling need for therapies that could improve disease-free survival without severe toxicity,” said Heslop. “Radiation and chemotherapy, the traditional treatments for nasopharyngeal carcinoma, frequently fail and can cause severe long-term side effects. It would be nice if we could substitute less toxic therapy.”
In addition to studying nasopharyngeal carcinoma, Heslop and her collaborators Cliona Rooney, Ph.D., professor of medicine and pediatrics at BCM; Malcolm Brenner, MBBCH, Ph.D., director of the Center for Cell and Gene Therapy and professor of medicine and pediatrics at BCM; Catherine Bollard, MBBS, assistant professor of medicine and pediatrics at BCM, and Stephen Gottschalk, M.D., assistant professor of medicine and pediatrics at BCM, are examining the role of specialized T-cells in late stages of Hodgkin’s disease and non-Hodgkin’s lymphoma The research team is currently conducting follow-up studies that improve the efficacy of these specialized T-cells while also testing them in earlier stages of both kinds of cancers.
“What we’ve got to work out is defining for which patients this treatment works and also try to improve the response rate,” said Heslop.