R-MVST Cells for Treatment of Viral Infections in Children and Young Adults

The primary objective is to determine the safety and feasibility of administering R-MVST cells to patients with refractory viral reactivation and/or symptomatic disease caused by Epstein Barr Virus (EBV), cytomegalovirus (CMV), adenovirus (ADV) or BK virus. R-MVST cells will be generated on-demand from the closest partially human leukocyte antigen (HLA)-matched (minimum haploidentical) healthy donors or from the original allo-transplant donor if available. The investigator will closely monitor the recipients for potential toxicities including graft-versus-host disease (GVHD) post-infusion. Secondary objectives are to determine the effect of R-MVST infusion on viral load, possible recovery of antiviral immunity post-infusion and for evidence of clinical responses and overall survival. Recipients will be monitored for secondary graft failure at day 28 post R-MVST infusion.

Starting from childhood, majority of healthy humans are exposed to common viruses such as CMV, EBV, BK and related human polyomaviruses and herpes viruses. Under normal circumstances those infections are well controlled by the adaptive immune system, but never eliminated. Instead, they are fairly inactive and produce relatively few consequences or symptoms. However, when T cell mediated immunity is suppressed, those dormant viruses reactivate and can cause a significant end-organ or severe systemic syndrome. This viral reactivation contributes to morbidity and mortality in recipients of allogeneic stem cell transplant (HCT) and solid organ transplants (SOT), and can affect many other patients who receive immunosuppressive therapies or have underlying pathology that affects T cell function, including patients with autoimmune diseases, congenital immunodeficiencies or HIV/AIDS. As a result of a weakened immune response, conventional antiviral prophylaxis or treatment with acyclovir and ganciclovir/foscarnet (for CMV) or rituximab (against EBV) are not always effective. The main purpose of this study is to test whether giving an experimental cell product can treat the viral infection in patients who have conditions that cause poor function of their immune system, such as infections caused by viruses such as Cytomegalovirus (CMV), Epstein-Barr Virus (EBV), BK virus, or adenovirus. The cell product is called rapidly generated virus specific T cells or R-MVST. This is a single center, Phase 1, non-randomized open-label dose escalation study in three groups of immunocompromised patients. The recipients of allogeneic HCT who will be enrolled in Group A, while SOT recipients will be enrolled in Group B and non-transplanted immunocompromised recipients will be enrolled in Group C. Each group will undergo independent dose escalation.