Allogeneic Virus-specific T Cell Lines (VSTs)

The primary purpose of the study is to evaluate whether most closely HLA-matched multivirus-specific T cell lines obtained from a bank of allogeneic virus-specific T cell lines (VSTs) have antiviral activity against three viruses: EBV, CMV and adenovirus. Reconstitution of anti-viral immunity by donor-derived VSTs has shown promise in preventing and treating infections associated with CMV, EBV and adenovirus post-transplant. However, the time taken to prepare patient-specific products and lack of virus-specific memory T cells in cord blood and seronegative donors, limits their value. An alternative is to use banked partially HLA-matched allogeneic VSTs. A prior phase II study at our institution using trivirus-specific VSTs generated using monocytes and EBV-transformed B cells gene-modified with a clinical grade adenoviral vector expressing CMV-pp65 to activate and expand specific T cells showed the feasibility, safety and activity of this approach for the treatment of refractory CMV, EBV and Adenovirus infections. However, the production process was lengthy, requiring 8-12 weeks, with exposure to biohazards (B95.8 EBV viral strain and adenovector), while antigenic competition between different viral components precluded increasing the spectrum of specificity beyond these three viruses. Investigator have overcome these limitations and in the current trial, they will evaluate whether rapidly generated, allogeneic most closely HLA-matched multivirus-specific VSTs, activated using overlapping peptide libraries spanning immunogenic antigens from CMV, adenovirus and EBV will be safe and produce anti-viral effects in allogeneic HSCT recipients infected with one of more of the targeted viruses that are persistent despite conventional anti-viral therapy. The study agent will be assessed for safety (stopping rules defined) and antiviral activity.