Targeted immunotherapy has been an attractive new therapeutic area for a number of cancers because it has the potential to destroy tumor cells without damaging surrounding normal tissue. New study results demonstrate high success rates using specialized white blood cells to prevent or treat lymphoma associated with the Epstein-Barr virus (EBV-lymphoma) in patients who have received a hematopoietic stem cell transplant (HSCT). This study was pre-published online today in Blood, the official journal of the American Society of Hematology.
Lymphoma is a cancer of white blood cells called lymphocytes that are largely responsible for maintaining the body's immunity, and EBV is one of the most common human viruses that can have a long-lasting impact on the body's immune system. Immune-compromised patients who receive HSCT, especially from mismatched donors or matched but unrelated donors, may be at higher risk of developing EBV-lymphoma than other patients. Previous studies have suggested that EBV-lymphoma occurs most often in the first few months post-transplant.
The researchers hypothesized that aggressive EBV-lymphomas may be responsive to control or eradication with EBV-specific cytotoxic T lymphocyte (CTL) treatment. (CTLs are highly specialized white blood cells that build the body's defenses against disease.) To test their theory, the team infused EBV-specific CTL lines into two groups of patients: those who were undergoing HSCT and were at high risk of developing EBV-lymphoma, and patients who had already developed lymphoma. The study reported that CTL treatment successfully prevented the development of EBV-lymphoma in all 101 patients in the at-risk group who received the therapy prophylactically and achieved sustained complete remission in 11 of the 13 patients (85 percent) treated therapeutically (those who already had the disease).
"Therapy with EBV-specific CTLs was effective for these severely immunocompromised patients. The CTLs successfully reached tumors, multiplied, and were able to kill the tumor cells," said lead study author Helen Heslop, MD, of the Center for Cell and Gene Therapy at Baylor College of Medicine, The Methodist Hospital, and Texas Children's Hospital.