Outcomes following posttransplant viral-specific T-cell therapy in patients with sickle cell disease

Hematopoietic stem cell transplantation (HSCT) is increasingly used as a curative approach for sickle cell disease (SCD). With the risk of graft-versus-host disease (GVHD), especially in the HLA-mismatched donors, intense immunosuppression is required leading to an increased risk of viral infection. Post-HSCT, adoptive transfer of virus-specific T cell (VSTs) therapies have not been well-studied in SCD patients. Here, we report the outcomes of patients with SCD at a single-center who received VSTs post-transplant to prevent or treat virus infections. Thirteen patients who received HSCT from HLA-matched (n=9) or mismatched (n=4) donors for SCD were treated with a total of 15 VST products for the treatment or prophylaxis of multiple viruses (cytomegalovirus, ebstein barr virus, adenovirus, BK virus, human herpes virus 6 +/- human parainfluenza virus 3). Of the patients evaluated, 46.2% (n=6)) received VSTs as treatment of virus infection. Eighty percent of patients with active viremia (n=4/5) achieved remission of at least 1 target virus. Seven additional patients (53.8%) received VSTs prophylactically and 6/7 (85.7%) remained virus-free post-infusion. No immediate infusion-related toxicities occurred, and severe de novo acute GVHD occurred in only 2 (15.4%) patients. Given the good safety profile, high-rate of clinical responses and sustained remissions when administered with standard anti-viral treatments, the routine use of VSTs post-HSCT as prophylaxis or treatment may improve the overall safety of transplant for patients with SCD.