Extended duration letermovir in allogeneic hematopoietic stem cell transplant

Area of Science:

• Hematology
• Infectious Diseases
• Transplant Medicine

Background:

• Cytomegalovirus (CMV) infection poses significant risks post-allogeneic hematopoietic cell transplant (HCT).
• Current letermovir prophylaxis guidelines recommend use up to 100 days post-HCT for CMV-seropositive recipients.
• The benefit of extending letermovir prophylaxis beyond 100 days remains unclear.

Purpose of the Study:

• To evaluate the efficacy of extended duration letermovir prophylaxis in preventing CMV reactivation.
• To compare CMV reactivation rates between standard (≤100 days) and extended (>100 days) letermovir prophylaxis in CMV-seropositive HCT recipients.

Main Methods:

• Retrospective chart review of 87 CMV-seropositive allogeneic HCT recipients.
• Patients initiated letermovir between days 0-28 post-transplant.
• Comparison of CMV reactivation rates between standard and extended letermovir prophylaxis groups.

Main Results:

• Extended letermovir prophylaxis (median 132 days) was associated with lower CMV reactivation rates (19%) compared to standard duration (median 78 days, 28%).
• One case of CMV pneumonitis occurred in the standard duration group.
• All-cause mortality at day 200 was similar between groups.

Conclusions:

• Extended letermovir prophylaxis beyond 100 days may reduce CMV reactivation in CMV-seropositive HCT recipients.
• Further research may support longer prophylaxis durations to mitigate CMV complications.