Clearance of viremia was defined as documentation of two negative PCR values (i.e., below level of detection) obtained at least one week apart. The first negative of the two negative PCR values was considered as date of clearance. Time to reactivation corresponds to time from HCT (day 0) to first detectable viremia. Time to spontaneous clearance was defined as time from first detectable viremia to clearance, as defined above, in the absence of antiviral therapy. Time to treatment-induced clearance, among those who received antivirals, was defined from date of initiation of anti-CMV therapy to clearance. Therapeutic failure was defined as inability to achieve clearance of viremia, as defined above, in response to antivirals (and other interventions such as tapering of immunosuppression and, in one case, adoptive T-cell immunotherapy). All-cause mortality and NRM (defined as death without recurrent or progressive disease after HCT) were calculated at 100, 200 and 365 days post-HCT.