ASH Clinical News May 2015 | Page 58

On Location Study Evaluates Safety of Cytotoxic T Lymphocytes for Rituximab-Refractory Epstein-Barr Virus For patients who have undergone stem cell or organ transplantation, the drugs administered to prevent organ rejection can weaken the immune system, which can lead to Epstein-Barr virus-associated lymphoproliferative disorder (EBV-LPD). “Historically, the life expectancy for somebody who developed an EBV lymphoma was less than 30 days,” said Susan E. Prockop, MD, a pediatric oncologist at the Memorial Sloan Kettering Cancer Center in New York at the American Association for Cancer Research meeting. While rituximab is a standard line of treatment for these patients, the drug induces remissions in only approximately 55 percent of patients with radiographically demonstrable disease, and the median survival for rituximab-refractory patients is 16 to 56 days. New research presented by Dr. Prockop found that more than 60 percent of patients with rituximab-refractory (EBV-LPD) responded to cytotoxic T lymphocyte (CTL) therapy. EBV-LPD most frequently presents as malignant, high-grade, diffuse large B-cell lymphomas that do not respond to the usual first approach to these disorders, of reducing or eliminating the drugs suppressing the immune system. In the current investigation, Dr. Prockop and researchers evaluated the safety and efficacy of EBV-CTLs in two clinical trials that included 57 allogeneic hematopoietic cell transplant patients with EBV disease. • Patients in the first trial (n=39) had a median age of 21 years, and 28 had failed prior therapy with rituximab. • Patients in the second trial (n=18) had a median age of 52 years, and all had failed prior rituximab therapy. In both studies, patients received up to five cycles of EBV-CTL infusions, with each session consisting of one or two infusions of 106 cells/kg weekly for three weeks. Richard J. O’Reilly