All investigator-determined cases of CMV disease (i.e., CMV infection or CMV organ disease), were adjudicated by an independent, blinded EC. CMV infection was assessed by (1) pp65 antigenemia assay; (2) CMV DNA polymerase chain reaction (PCR); (3) either assay (pp65 antigenemia or CMV DNA PCR); or (4) initiation of anti-CMV therapy. CMV infection was defined as: CMV infection detected by a positive result from a CMV laboratory assay from at least one central laboratory assay (pp65 antigenemia or CMV DNA PCR assay in plasma) and fever >/=38 °C on >/=2 occasions >/=24 hours apart within a 7-day period and at least one of the following: new or increased malaise, two successive measurements of leucopenia (white blood cell [WBC] count <3500/mm3 or a WBC count decrease of 20% if the cell count prior to onset of clinical symptoms was >4000/mm3) >/=24 hours apart, atypical lymphocytosis >/=5%, and thrombocytopenia. CMV organ disease was defined as described by Ljungman et al., 2002.

The Intent-to-Treat (ITT) population, defined as all participants who were randomized to one of the therapy groups, regardless of whether the participant received study drug or had any post-baseline evaluations.

All investigator-determined cases of CMV disease (i.e., CMV infection or CMV organ disease), were adjudicated by an independent, blinded EC. CMV infection was assessed by (1) pp65 antigenemia assay; (2) CMV DNA polymerase chain reaction (PCR); (3) either assay (pp65 antigenemia or CMV DNA PCR); or (4) initiation of anti-CMV therapy. CMV infection was defined as: CMV infection detected by a positive result from a CMV laboratory assay from at least one central laboratory assay (pp65 antigenemia or CMV DNA PCR assay in plasma) and fever >/=38 °C on >/=2 occasions >/=24 hours apart within a 7-day period and at least one of the following: new or increased malaise, two successive measurements of leucopenia (white blood cell [WBC] count <3500/mm3 or a WBC count decrease of 20% if the cell count prior to onset of clinical symptoms was >4000/mm3) >/=24 hours apart, atypical lymphocytosis >/=5%, and thrombocytopenia. CMV organ disease was defined as described by Ljungman et al., 2002.

The ITT population, defined as all participants who were randomized to one of the therapy groups, regardless of whether the participant received study drug or had any post-baseline evaluations.

All investigator-determined cases of CMV disease (i.e., CMV infection or CMV organ disease) were adjudicated by an independent, blinded EC. CMV infection was assessed by (1) pp65 antigenemia assay or (2) CMV DNA polymerase chain reaction (PCR). CMV infection was defined as: CMV infection detected by a positive result from a CMV laboratory assay from at least one central laboratory assay (pp65 antigenemia or CMV DNA PCR assay in plasma) and fever >/=38 °C on >/=2 occasions >/=24 hours apart within a 7-day period and at least one of the following: new or increased malaise, two successive measurements of leucopenia (white blood cell [WBC] count <3500/mm3 or a WBC count decrease of 20% if the cell count prior to onset of clinical symptoms was >4000/mm3) >/=24 hours apart, atypical lymphocytosis >/=5%, and thrombocytopenia. CMV organ disease was defined as described by Ljungman et al., 2002.

The ITT population, defined as all participants who were randomized to one of the therapy groups, regardless of whether the participant received study drug or had any post-baseline evaluations.

CMV infection was assessed by (1) pp65 antigenemia assay; (2) CMV DNA polymerase chain reaction (PCR); (3) either assay (pp65 antigenemia or CMV DNA PCR); or (4) initiation of anti-CMV therapy. CMV infection was defined as: CMV infection detected by a positive result from a CMV laboratory assay from at least one central laboratory assay (pp65 antigenemia or CMV DNA PCR assay in plasma) and fever >/=38 °C on >/=2 occasions >/=24 hours apart within a 7-day period and at least one of the following: new or increased malaise, two successive measurements of leucopenia (white blood cell [WBC] count <3500/mm3 or a WBC count decrease of 20% if the cell count prior to onset of clinical symptoms was >4000/mm3) >/=24 hours apart, atypical lymphocytosis >/=5%, and thrombocytopenia. CMV organ disease was defined as described by Ljungman et al., 2002.

The ITT population, defined as all participants who were randomized to one of the therapy groups, regardless of whether the participant received study drug or had any post-baseline evaluations.

All investigator-determined cases of CMV disease (i.e., CMV infection or CMV organ disease), were adjudicated by an independent, blinded EC. CMV infection was assessed by (1) pp65 antigenemia assay; (2) CMV DNA polymerase chain reaction (PCR); (3) either assay (pp65 antigenemia or CMV DNA PCR); or (4) initiation of anti-CMV therapy. CMV infection was defined as: CMV infection detected by a positive result from a CMV laboratory assay from at least one central laboratory assay (pp65 antigenemia or CMV DNA PCR assay in plasma) and fever >/=38 °C on >/=2 occasions >/=24 hours apart within a 7-day period and at least one of the following: new or increased malaise, two successive measurements of leucopenia (white blood cell [WBC] count <3500/mm3 or a WBC count decrease of 20% if the cell count prior to onset of clinical symptoms was >4000/mm3) >/=24 hours apart, atypical lymphocytosis >/=5%, and thrombocytopenia. CMV organ disease was defined as described by Ljungman et al., 2002.

The ITT population, defined as all participants who were randomized to one of the therapy groups, regardless of whether the participant received study drug or had any post-baseline evaluations.

All investigator-determined cases of CMV disease (i.e., CMV infection or CMV organ disease), were adjudicated by an independent, blinded EC. CMV infection was assessed by (1) pp65 antigenemia assay; (2) CMV DNA polymerase chain reaction (PCR); (3) either assay (pp65 antigenemia or CMV DNA PCR); or (4) initiation of anti-CMV therapy. CMV infection was defined as: CMV infection detected by a positive result from a CMV laboratory assay from at least one central laboratory assay (pp65 antigenemia or CMV DNA PCR assay in plasma) and fever >/=38 °C on >/=2 occasions >/=24 hours apart within a 7-day period and at least one of the following: new or increased malaise, two successive measurements of leucopenia (white blood cell [WBC] count <3500/mm3 or a WBC count decrease of 20% if the cell count prior to onset of clinical symptoms was >4000/mm3) >/=24 hours apart, atypical lymphocytosis >/=5%, and thrombocytopenia. CMV organ disease was defined as described by Ljungman et al., 2002.

The ITT population, defined as all participants who were randomized to one of the therapy groups, regardless of whether the participant received study drug or had any post-baseline evaluations.

Analysis of acute GVHD was based on reported adverse events that mapped to the relevant MedDRA dictionary terms for acute GVHD. The percentage reported is for the occurrence of any grade of acute GVHD.

The ITT Safety (ITT-S) population, defined as participants in the ITT population who received at least one dose of study drug.

Analysis of chronic GVHD was based on reported adverse events that mapped to the relevant MedDRA dictionary terms for chronic GVHD. The percentage reported is for the occurrence of any grade of chronic GVHD.

The ITT-S population, defined as participants in the ITT population who received at least one dose of study drug.

The ITT-S population, defined as participants in the ITT population who received at least one dose of study drug.

Pharmacokinetic (PK) profile sampling was performed to evaluate plasma concentrations of Maribavir. During the study drug administration period, blood samples for this purpose were collected on Day 7 (Week 1) and at Week 4. Every effort was made to ensure that doses were administered 12 hours apart on the day before and on the day of PK sampling. Permissible assessment windows for PK profile sampling purposes were +/- 3 days and +/- 5 days for the 1- and 4- week samples, respectively. Samples were analyzed by a validated liquid chromatography tandem mass spectrometry (LC/MS/MS) method. The validated lower limit of quantitation (LLOQ) in plasma was 0.2 μg/mL.

The pharmacokinetic (PK) population, defined as those participants in the ITT population from whom plasma samples were drawn, tested for maribavir concentrations, and complete, evaluable PK data were available.

Pharmacokinetic (PK) profile sampling was performed to evaluate plasma concentrations of VP 44469, a metabolite of Maribavir. During the study drug administration period, blood samples for this purpose were collected on Day 7 (Week 1) and at Week 4. Every effort was made to ensure that doses were administered 12 hours apart on the day before and on the day of PK sampling. Permissible assessment windows for PK profile sampling purposes were +/- 3 days and +/- 5 days for the 1- and 4- week samples, respectively. Samples were analyzed by a validated liquid chromatography tandem mass spectrometry (LC/MS/MS) method. The validated lower limit of quantitation (LLOQ) in plasma was 0.2 μg/mL.

The PK population, defined as those participants in the ITT population from whom plasma samples were drawn, tested for maribavir concentrations, and complete, evaluable PK data were available.