HORUS-Cytomegalovirus Open Proof-of-concept Exploratory Trial

Inclusion Criteria: * Clinically stable adult patients (aged 18 years or older) who have received a solid organ transplant (e.g., kidney, liver, heart, lung, pancreas) and developed clinically significant CMV infection as determined by positive CMV PCR. * On maintenance therapy of tacrolimus, MPA, +/- steroids. * Informed consent signed. Exclusion Criteria: * Active acute graft rejection or significant graft dysfunction requiring modification of the current immunosuppressive regimen, in the opinion of the investigator. * Receipt of more than 72 hours of antiviral therapy for CMV infection prior to enrolment, before randomization, including valganciclovir and/or IV ganciclovir therapy * Known intolerance or hypersensitivity to mTOR inhibitors or to any component of the everolimus formulation. * Any medical condition that constitutes a contraindication to everolimus use, as judged by the investigator. * Additional exclusion criteria for French sites: * Patient not affiliated to the French social security system * Patient under legal protection (guardianship, curatorship).