A Clinical Study of Letermovir (MK-8228) in Children and Adolescents Who Receive a Kidney Transplant (KT) (MK-8228-077)
A Phase 1, Open-label, Single-arm Study to Evaluate the Pharmacokinetics and Safety of Letermovir in Pediatric Kidney Transplant (KT) Recipients Less Than 18 Years of Age and Weighing Less Than 40 Kilograms
2 other identifiers
interventional
40
1 country
12
Brief Summary
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). The goals of the study are to:
- Learn what happens to letermovir in the body over time
- Learn about the safety of letermovir and if participants tolerate it
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P50-P75 for phase_1
Started Mar 2026
Typical duration for phase_1
12 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
September 22, 2025
CompletedFirst Posted
Study publicly available on registry
September 30, 2025
CompletedStudy Start
First participant enrolled
March 30, 2026
CompletedPrimary Completion
Last participant's last visit for primary outcome
April 14, 2028
ExpectedStudy Completion
Last participant's last visit for all outcomes
May 19, 2028
April 20, 2026
April 1, 2026
2 years
September 22, 2025
April 16, 2026
Conditions
Outcome Measures
Primary Outcomes (1)
Area Under the Curve From Time 0 to 24 Hours (AUC0-24)
Blood samples will be collected at multiple time points to estimate AUC0-24
Day 7: Predose and at designated timepoints post-dose (up to 24 hours)
Secondary Outcomes (2)
Percentage of Participants Who Experience an Adverse Event (AE)
Up to 21 days
Percentage of Participants Who Discontinue Study Intervention Due to an AE
Up to 7 days
Study Arms (1)
Weight-banded letermovir dosing
EXPERIMENTALParticipants who are between 4 and 52 weeks post-KT will receive letermovir for 7 consecutive days.
Interventions
Administered orally (as tablets/pellets) or via gastrostomy or nasogastric tube (as pellets) for 7 consecutive days.
Eligibility Criteria
You may qualify if:
- 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)
You may not qualify if:
- 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
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (12)
UCLA Clinical & Translational Research Center (CTRC) ( Site 0006)
Los Angeles, California, 90095, United States
Lucile Packard Children's Hospital ( Site 0001)
Palo Alto, California, 94304, United States
University of California Davis Health ( Site 0023)
Sacramento, California, 95817, United States
UCSF Medical Center at Mission Bay ( Site 0017)
San Francisco, California, 94158, United States
Children's Hospital Colorado ( Site 0013)
Aurora, Colorado, 80045, United States
Ann & Robert H. Lurie Children's Hospital of Chicago ( Site 0004)
Chicago, Illinois, 60611, United States
University of Michigan ( Site 0014)
Ann Arbor, Michigan, 48109, United States
M Health Fairview University of Minnesota Masonic Children's Hospital, West Bank ( Site 0007)
Minneapolis, Minnesota, 55454, United States
Mayo Clinic - Rochester ( Site 0015)
Rochester, Minnesota, 55905, United States
Morgan Stanley Children's Hospital ( Site 0018)
New York, New York, 10032, United States
Duke University Medical Center ( Site 0008)
Durham, North Carolina, 27710, United States
Cincinnati Children's Hospital Medical Center ( Site 0002)
Cincinnati, Ohio, 45229, United States
Related Links
MeSH Terms
Interventions
Study Officials
- STUDY DIRECTOR
Medical Director
Merck Sharp & Dohme LLC
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- phase 1
- Allocation
- NA
- Masking
- NONE
- Purpose
- TREATMENT
- Intervention Model
- SINGLE GROUP
- Sponsor Type
- INDUSTRY
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
September 22, 2025
First Posted
September 30, 2025
Study Start
March 30, 2026
Primary Completion (Estimated)
April 14, 2028
Study Completion (Estimated)
May 19, 2028
Last Updated
April 20, 2026
Record last verified: 2026-04
Data Sharing
- IPD Sharing
- Will share
https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf