NCT07199465 · Merck Sharp & Dohme LLC
A Clinical Study of Letermovir (MK-8228) in Children and Adolescents Who Receive a Kidney Transplant (KT) (MK-8228-077)
What this study is about
Researchers are looking for a way to prevent cytomegalovirus (CMV) in children and adolescents who receive a kidney transplant (KT) and weigh less than 40 kilograms (88.2 pounds).
View original scientific description
Researchers are looking for a way to prevent cytomegalovirus (CMV) in children and adolescents who receive a kidney transplant (KT) and weigh less than 40 kilograms (88.2 pounds).
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- The main inclusion criteria include but are not limited to the following:
- Is a recipient of a primary or secondary allograft kidney
- Is at least 4 weeks posttransplant and not more than 52 weeks posttransplant at the time of enrollment (Day 1) and is being managed per local standard of care
- Has stable kidney function posttransplant
- Has undetectable CMV deoxyribonucleic acid (DNA) from a plasma or whole blood sample collected within 14 days prior to enrollment
- Must be able to take (as assessed by the investigator) letermovir tablets or oral pellets by mouth, or via gastrostomy or nasogastric tube (oral pellets only)
- Does not have a condition that may interfere with the absorption of oral medication (e.g., vomiting, diarrhea, or a malabsorptive condition) from the day of enrollment (Day 1) until the intensive pharmacokinetics (IPK) sampling is completed
- Weighs ≥2.5 and \<40 kg at enrollment (Day 1)
Exclusion criteria
- The main exclusion criteria include but are not limited to the following:
- Has CMV disease or suspected CMV disease between screening and enrollment
- Is on dialysis or plasmapheresis at the time of enrollment
- Has evidence of CMV viremia at any time from screening until the time of enrollment
- Has Child-Pugh B or C hepatic insufficiency within 14 days before enrollment
- Is a multi-organ transplant recipient (e.g., kidney-pancreas)
- Has any uncontrolled infection on the day of enrollment
- Requires mechanical ventilation, or is hemodynamically unstable, at the time of enrollment
- Has received or is receiving protocol-specified prohibited medications
Where
- Birmingham, Alabama
- Los Angeles, California
- Palo Alto, California
- Sacramento, California
- San Francisco, California
- Aurora, Colorado
- Miami, Florida
- Chicago, Illinois
- Ann Arbor, Michigan
- Minneapolis, Minnesota
- Rochester, Minnesota
- New York, New York
And 5 more locations — see the full list below.
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 12, 2026 · Source of record for eligibility and locations