Virus-Specific T Cells for Hematopoietic Stem Cell Transplantation

Purpose of Review: During the period of T cell immune recovery after hematopoietic stem cell transplantation (HSCT), viral infections and reactivation are a major cause of morbidity and mortality. Adoptive immunotherapy using virus-specific T cells (VSTs) derived from virus-exposed or naïve donors has emerged as an effective strategy to prevent viral complication early after HSCT. Recent Findings: Early-phase clinical trials show that such VSTs can both prevent and treat viral infections in 70–90% of patients, are safe, and are well tolerated with no infusion-related adverse events and/or worsening of graft-versus-host disease. These clinical trials have a tremendous potential in preventing and treating viral infections post HSCT. The field of adoptive T cell therapy has made huge strides to overcome some of the challenges such as cumbersome manufacturing strategies, targeting multiple viral antigens, and making the T cell product widely available through third-party banks. A collaborative effort between academic centers and industry is likely to facilitate the broader implementation and accessibility of these novel therapies. It will also enable randomized phase 3 clinical trials to prove the efficacy of these T cell products in comparison to often expensive and ineffective pharmacotherapies. Summary: Here we review the current methods of VST generation, clinical results using VSTs in the HSCT setting, and applications of VSTs to treat viral-associated malignancies. © 2017, Springer International Publishing AG.