Letermovir use for cytomegalovirus prophylaxis following lung transplantation: A single-center review

Abstract

Cytomegalovirus (CMV) remains a major cause of infection following solid organ transplant and valganciclovir prophylaxis is the standard of care. However, valganciclovir associated myelosuppression limits its tolerability and can require dose reduction in immunosuppression, particularly cell cycle inhibitors, or changes in antimicrobial prophylaxis. Letermovir, a viral terminase inhibitor, is approved by the FDA for use as CMV prophylaxis in kidney transplant recipients; data on its use in lung transplant recipients (LTRs) is limited. We performed a single-center retrospective cohort study of LTRs prescribed letermovir for prophylaxis between 1/1/18-9/1/23. Over the study period, 88 LTRs were prescribed letermovir with most (93%) switching due to myelosuppression while on valganciclovir. Of those prescribed letermovir, 67 (76%) actually started letermovir, with the primary barrier being insufficient insurance coverage or high copay cost. Among LTRs who started letermovir due to myelosuppression, 90% had improvement in their leukopenia or neutropenia, with a significant increase in white blood cell count one month after switching therapy (P<0.0001). Additionally, 46% of those who were not receiving a cell cycle inhibitor previously were able to restart this after switching to letermovir. CMV was detected in 14 LTRs following letermovir switch, with two discontinuing letermovir due to breakthrough CMV. Our findings support the use of letermovir for CMV prophylaxis in LTRs with possible benefits over valganciclovir, although a direct comparison is needed.