CMV Infection Prevention with Letermovir in HSCT Recipients – Phase IIb

Study of Letermovir in Pediatric Participants from Birth to Less than 18 Years of Age at Risk of Developing CMV Infection and/or Disease Following Allogeneic Hematopoietic Stem Cell Transplantation

Protocol Description

This research study evaluates the drug letermovir (LET or MK-8228) for prevention of cytomegalovirus (CMV) infection in pediatric patients who have received an allogeneic hematopoietic stem cell transplant (HSCT). LET has been approved in the United States and other countries for use in adults who have received an allogeneic HSCT for prevention of CMV infection and disease; however, it has not yet been approved for children who have received an allogeneic HSCT.

Study Level: Phase IIb

Eligibility Criteria

Subject to certain exclusion criteria, this study is enrolling pediatric patients who have received an allogeneic HSCT.
Boys and Girls: Ages birth through 17


Within 28 days after the transplant, LET will be administered either orally or intravenously, once daily through week 14 (approximately 100 days). Dosing will vary based on age, weight, and whether the participant also takes the medication cyclosporin. Blood testing will also be done at intervals to evaluate how the body processes LET, and participants will be monitored for side effects and presence of CMV.
Visits: Up to 19
Duration: About 50 weeks

Status: Open to Enrollment

Source(s) of Support

Merck Sharp & Dohme

Primary Investigator

Jessie Barnum, MD

Contact Information

For more information about the study or enrollment, please contact:
Shawna McIntyre, Clinical Research Supervisor