A Study of Maribavir in Chinese Adults With Cytomegalovirus (CMV) Infections

Inclusion Criteria

• •The participant or the participant's legally acceptable representative is willing and able to understand and fully comply with study procedures and requirements, in the opinion of the investigator.
• •The participant/participant's legally representative has provided informed consent (that is, in writing, documented via a signed and dated informed consent form \[ICF\]) and any required privacy authorization prior to the initiation of any study procedures.
• •The participant is aged 18 years or older (ie, greater than or equal to \[\>=\] 18 years) at the time of signing the ICF.
• •The participant must be of Chinese descent, defined as born in China and having Chinese parents and Chinese maternal and paternal grandparents.
• •The participant must be a recipient of hematopoietic stem cell or solid organ transplant.
• •The participant must have a documented CMV infection in whole blood or plasma, with a screening value of \>=1,365 International unit per milliliter IU/mL in whole blood or \>=455 IU/mL in plasma in 2 consecutive assessments, separated by at least 1 day, as determined by local laboratory quantitative polymerase chain reaction (qPCR) or comparable quantitative CMV DNA results. Both samples should be taken within 14 days prior to receiving the investigational product with second sample obtained within 5 days prior to receiving the investigational product. The same laboratory and same sample type (whole blood or plasma) must be used for these assessments.
• •The participant must have a current CMV infection that is refractory to the most recently administered of the 4 anti-CMV treatment agent(s) eg, intravenous (IV) ganciclovir/oral valganciclovir, IV foscarnet, or IV cidofovir. Refractory is defined as documented failure to achieve greater than (\>) 1 log10 (common logarithm to base 10) decrease in CMV DNA level in whole blood or plasma after a 14 day or longer treatment period with the above 4 agents.
• •Participants who have documentation of 1 or more CMV genetic mutations associated with resistance to ganciclovir/valganciclovir, cidofovir, or foscarnet must also meet the definition of refractory CMV infection.
• •Have all the following results as part of screening laboratory assessments:
• •* Absolute neutrophil count \>=1000 per cubic millimeter (/mm\^3) (1\*10\^9 per liter \[/L\]).
• •* Platelet count \>= 25,000/mm\^3 (25\*10\^9/L)
• •* Hemoglobin \>= 8 grams per deciliter (g/dL)
• •* Estimated glomerular filtration rate \>= 30 milliliter per minute per 1.73 square meter (mL/min/1.73 m\^2) as assessed by Modification of Diet in Renal Disease (MDRD) formula.
• •The participant must have life expectancy of at least 8 weeks.
• •The participant has a body weight of at least 35 kilogram (kg).
• •The female participant either be of nonchildbearing potential, or if of childbearing potential then have a negative serum human chorionic gonadotropin (hCG) or beta-hCG (β-hCG) pregnancy test at screening. Males, or nonpregnant, nonlactating female participants who are sexually active must agree to comply with the applicable contraceptive requirements of this protocol during the investigational product administration period and for 90 days after the last dose of investigational product.
• •The participant must be able to swallow tablets, or receive tablets crushed and/or dispersed in water via a nasogastric or orogastric tube.