CMV-MVA Triplex Vaccination in HLA-Matched Related Stem Cell Donors for the Prevention of CMV Infection in Patients Undergoing Hematopoietic Stem Cell Transplant

PRIMARY OBJECTIVE: I. To determine whether multi-peptide CMV-modified vaccinia Ankara vaccine (Triplex) is safe and effective in protecting against CMV events defined as viremia requiring antiviral preemptive therapy (PET) or CMV end organ disease. SECONDARY OBJECTIVE: I. To examine if Triplex vaccination of hematopoietic stem cell transplant (HCT) donors has an impact on CMV events. OUTLINE: Donors are randomized to 1 of 2 arms. ARM I: DONORS: Donors receive Triplex vaccine intramuscularly (IM) on day 0 and then undergo stem cell mobilization with granulocyte colony-stimulating factor (G-CSF) on days 5 to 9 and apheresis for peripheral blood stem cell collection on days 10 to 14 per standard of care. Donors may optionally undergo blood sample collection on study. RECIPIENTS: Recipients undergo pre-transplant conditioning on days -60 to 0 and undergo HCT with the donor peripheral blood stem cells within 9 weeks of donor vaccination on day 0. Recipients undergo blood sample collection on study. ARM II: DONORS: Donors receive placebo IM on day 0 and undergo stem cell mobilization with G-CSF on days 5 to 9 and apheresis for peripheral blood stem cell collection on days 10 to 14 per standard of care. Donors may optionally undergo blood sample collection on study. RECIPIENTS: Recipients undergo pre-transplant conditioning on days -60 to 0 and undergo HCT with the donor peripheral blood stem cells within 9 weeks of donor vaccination on day 0. Recipients undergo blood sample collection on study. After completion of study treatment, donors follow up on days 90, 180 and 365 after vaccination and recipients follow up on days 14, 28, 42, 56, 70, 100, 140, 180, 270, and 365 after transplantation.