Multivirus-specific T-cell Transfer Post SCT vs AdV, CMV and EBV Infections

For a growing number of patients suffering from various conditions as, e.g., haematological malignancies or diverse genetic disorders, haematopoietic stem cell transplantation (HSCT) or bone marrow transplantation offer the only possible curative options. However, HSCT is associated with three major risks: graft rejection, graft-versus-host disease (GvHD) and opportunistic, mostly viral, infections or reactivations resulting from delayed immune reconstitution. Delayed immune reconstitution, however, often is the direct result of the severe pre-transplantation conditioning treatment and T-cell depletion of the transplant necessary to fight the risks of graft rejection and GvHD. Therefore, the risk for life-threatening opportunistic, mostly viral, infections is increased in post-transplantation patients. The most common infections after HSCT are Cytomegalovirus (CMV), Epstein-Barr virus (EBV) and Adenovirus (AdV).

The standard treatment approach for viral infections/reactivations is chemotherapy which shows limited efficacy and does not restore immunity. Therefore, effective new treatment options are required for this condition.

Previous investigations have shown that sufficient T-cell immunity is essential for the control and prevention of viral reactivations and newly occurring infections after HSCT. The infusion of T-cells is therefore a promising new approach to treat immune-comprised patients. However, infusion with unselected T cells is associated with an increased risk for GvHD due to the high content of alloreactive T cells. A very promising approach to minimize this problem is to remove alloreactive T cells and enrich, isolate and purify virus-specific T cells.

This approach has been studied for nearly two decades and the data published up to date indicate that virus-specific T-cell responses after adoptive T-cell transfer protect against virus-related complications post HSCT and restore T-cell immunity, in particular for AdV-, CMV- and EBV-infections. Despite these promising results, virus-specific T-cell transfer is not yet translated into daily clinical practice due to the lack of prospective clinical trials confirming the efficacy of this treatment approach.

The overall goal of this Phase III, double-blind placebo-controlled study is to test efficacy of multivirus-specific T cells to bring this treatment method in clinical routine. Multivirus-specific T cells generated in this study will be directed against all three most common post-HSCT viral infections: AdV, CMV and EBV. Thus, T-cell immunity will be restored to fight and prevent new viral infections.

After an initial screening visit, patients eligible to participate in the study will be treated within 28 days after screening. Patients will be randomized in a 2:1 (treatment: placebo) ratio and receive a single infusion with either multivirus-specific T cells or placebo. Patients will be followed up on the day of treatment, 1 day after and 1, 2, 4, 8 and 15 weeks after treatment. Treatment success will be measured by assessing different parameters including symptoms, quality of life, viral load and T-cell immunity in blood samples.

Patients eligible to participate in this study are adult and paediatric patients who have received allogeneic stem cell transplantation and suffer from new or reactivated EBV, AdV or CMV infection refractory to standard antiviral treatment for two weeks. Patients from the six European countries Germany, Belgium, Netherlands, UK, France and Italy will be enrolled. In total 130 patients plus 19 screening failures are expected to participate in the study.