Cytomegalovirus ProphylaxisPhase 1NCT07199465
A Clinical Study of Letermovir (MK-8228) in Children and Adolescents Who Receive a Kidney Transplant (KT) (MK-8228-077)
A Phase 1 study testing Letermovir in people with Cytomegalovirus Prophylaxis, run by Merck Sharp & Dohme LLC at 21 sites in United States.
Trial 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). Read more about this study
- Who is it for?
- Ages Up to 17 years
- Conditions the study is for
- Cytomegalovirus Prophylaxis
- What is being tested?
- Letermovir
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 40 participants
- Where
- 21 sitesUnited States
- Study dates
- 30 Mar 2026to 19 May 2028
- Phase
- Phase 1
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Up to 17 years
- All sexes
- No healthy volunteers
- Child
Who may be able to join
- 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)
Who cannot join
- 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)
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- 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
Trial locations and contacts
21 sites in 1 country. Contact the study team or a site near you to ask about taking part.
21 sites in 1 country
United States21 sites, 21 recruiting
- Recruiting
University of Michigan ( Site 0014)
Ann Arbor, Michigan, 48109
Study Coordinator, 734-936-6280
- Recruiting
Children's Healthcare of Atlanta-Center for Advanced Pediatrics ( Site 0020)
Atlanta, Georgia, 30329
Study Coordinator, 404-785-5437
- Recruiting
Children's Hospital Colorado ( Site 0013)
Aurora, Colorado, 80045
Study Coordinator, 720-777-6263
- Recruiting
University of Alabama at Birmingham - School of Medicine - Pediatrics ( Site 0019)
Birmingham, Alabama, 35233
Study Coordinator, 205-638-9781
- Recruiting
Levine Children's Hospital ( Site 0022)
Charlotte, North Carolina, 28203
Study Coordinator, 704-446-4842
- Recruiting
Ann & Robert H. Lurie Children's Hospital of Chicago ( Site 0004)
Chicago, Illinois, 60611
Study Coordinator, 312-227-2061
- Recruiting
Cincinnati Children's Hospital Medical Center ( Site 0002)
Cincinnati, Ohio, 45229
Study Coordinator, 513-636-3017
- Recruiting
Duke University-Pediatrics ( Site 0008)
Durham, North Carolina, 27710
Study Coordinator, 919-684-6335
- Recruiting
Texas Children's Hospital ( Site 0005)
Houston, Texas, 77030
Study Coordinator, 832-824-4330
- Recruiting
Children's Hospital Los Angeles ( Site 0016)
Los Angeles, California, 90027
Study Coordinator, 323-660-2450
- Recruiting
UCLA Clinical & Translational Research Center (CTRC) ( Site 0006)
Los Angeles, California, 90095
Study Coordinator, 310-825-5225
- Recruiting
University of Miami School of Medicine ( Site 0021)
Miami, Florida, 33136
Study Coordinator, 305-243-4445
- Recruiting
M Health Fairview University of Minnesota Masonic Children's Hospital, West Bank ( Site 0007)
Minneapolis, Minnesota, 55454
Study Coordinator, 612-365-0013
- Recruiting
Morgan Stanley Children's Hospital ( Site 0018)
New York, New York, 10032
Study Coordinator, 212-305-2500
- Recruiting
Lucile Packard Children's Hospital ( Site 0001)
Palo Alto, California, 94304
Study Coordinator, 408-828-5120
- Recruiting
Children's Hospital of Philadelphia (CHOP) ( Site 0003)
Philadelphia, Pennsylvania, 19104
Study Coordinator, 215-590-1000
- Recruiting
Children's Hospital of Pittsburgh - Department of Pediatrics ( Site 0011)
Pittsburgh, Pennsylvania, 15224
Study Coordinator, 412-864-6893
- Recruiting
Mayo Clinic - Rochester ( Site 0015)
Rochester, Minnesota, 55905
Study Coordinator, 507-254-1714
- Recruiting
University of California Davis Health ( Site 0023)
Sacramento, California, 95817
Study Coordinator, 916-734-8036
- Recruiting
UCSF Medical Center at Mission Bay ( Site 0017)
San Francisco, California, 94158
Study Coordinator, 415-347-1885
- Recruiting
Montefiore Medical Center ( Site 0024)
The Bronx, New York, 10467
Study Coordinator, 718-741-2426
About this study
Official title: 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
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
- Conditions
- Cytomegalovirus Prophylaxis
- Being tested
- Letermovir
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
LetermovirDrug
Also called MK-8228, AIC246, AIC001, PREVYMIS™
Administered orally (as tablets/pellets) or via gastrostomy or nasogastric tube (as pellets) for 7 consecutive days.
| Study group | Role | What they receive |
|---|---|---|
| Weight-banded letermovir dosing | Experimental | Participants who are between 4 and 52 weeks post-KT will receive letermovir for 7 consecutive days. Receives: Drug: Letermovir |
What is being measured
The primary outcome is the main question the study is designed to answer.
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
Measured: 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)
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention. The percentage of participants who experienced an AE is reported.
Measured: Up to 21 days
Percentage of Participants Who Discontinue Study Intervention Due to an AE
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention. The percentage of participants who discontinued study treatment due to an AE is reported.
Measured: Up to 7 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Sep 2025
- Study start30 Mar 2026
- Primary completion14 Apr 2028 (estimated)
- Study completion19 May 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Cytomegalovirus ProphylaxisStudies of the same condition, open and under way.
- More trials run by Merck Sharp & Dohme LLCThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Merck Sharp & Dohme LLC
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Medical Director, Study director, Merck Sharp & Dohme LLC
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07199465
- Sponsor's protocol ID
- 8228-077
- Other IDs
- MK-8228-077
- Status last verified
- Oct 2026
- First submitted
- 22 Sep 2025
- Last updated
- 13 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf