Impact of CMV-Specific Immune Reconstitution at the End of Letermovir Prophylaxis on the Development of Late Cytomegalovirus Infection in Hematopoietic Stem Cell Transplant Recipients (INMUNOEND)

Inclusion criteria

• Age >18 years.
• CMV seropositivity (positive IgG) in the recipient at the time of SCT.
• First allogeneic hematopoietic stem cell transplant recipient (bone marrow, peripheral blood, or cord blood).
• Within the first 28 days post-SCT at the time of inclusion.
• Indication for LTV prophylaxis within the first 28 days post-transplant up to 100 days post-SCT, according to the criteria established in each center.

Exclusion criteria

• CMV seronegativity (negative IgG) in the recipient at the time of transplant.
• Previous allogeneic stem cell transplant (patients with a prior autologous transplant are allowed to be included).
• History of CMV disease in the 6 months prior to inclusion.
• Need for preemptive therapy in the month prior to inclusion in the study.
• Received any of the following in the 14 days prior to inclusion: Ganciclovir, valganciclovir, foscarnet, acyclovir (at doses >3200 mg orally per day or >25 mg/kg IV per day), valacyclovir (at doses >3000 mg orally per day), famciclovir (at doses >1500 mg orally per day).
• Received any of the following in the 30 days prior to screening: Cidofovir, CMV hyperimmune immunoglobulin, any CMV antiviral in the investigational phase.
• Suspected or confirmed hypersensitivity reaction to the LTV formulation or any of its components.
• Severe hepatic insufficiency (defined as Child-Pugh class C).
• History of primary immunodeficiency prior to transplant.
• Participation in a clinical trial involving the administration of CMV vaccines, other investigational CMV drugs, or monoclonal antibodies.