Therapy with EBV-specific CTLs effective for severely immune-compromised patients

Nov 3 2009

Specially developed immune system cells that target the common Epstein-Barr virus can protect immune-suppressed bone marrow transplant recipients against lymph system disease and cancers that arise from the viral infection, said a group of researchers led by those from Baylor College of Medicine, The Methodist Hospital and Texas Children's Hospital.

"Therapy with EBV-specific CTLs (cytotoxic lymphocytes) was effective for these patients who were severely immune-compromised, as the cells successfully reached the tumor, multiplied and were able to kill tumor cells" said Dr. Helen Heslop, lead author of the study and professor of pediatrics and medicine and a member of the Center for Cell and Gene therapy at BCM, The Methodist Hospital and Texas Children's. The cell remained in the body for up to nine years, providing long-term protection.

Patients who undergo the transplants are often immune-suppressed. Because most people have been infected with Epstein-Barr virus, the lack of immune protection makes their lymph system vulnerable to adverse effects of the virus, especially lymphomas that can be traced directly back to the infection.

In this study, 114 patients who had received hematopoietic or blood-related stem cell transplants from an unrelated donor or a family member whose bone marrow was not a perfect match also received infusions of immune components called T-cells that were design to target Epstein-Barr virus-infected cells. The treatment was preventive in 101 patients, none of whom developed lymphomas associated with Epstein-Barr virus infection. Eleven of 13 patients who had this disease or symptoms of it had sustained remissions.

Because the cells were marked, researchers determined that the special cells remained in the body for as long as nine years. The cost of the therapy, which spares normal cells, was estimated at just over $6,000, which compares favorably to other treatments for the disorder.

Researchers infused the cells soon after the patients received the stem cell transplants, which could account for its success, said Heslop and her colleagues.

"With such a promising therapy, it's important that it is not only effective, but that it is a cost-effective option for high-risk patients," said Heslop.

Source: Baylor College of Medicine