Single-center experience with use of letermovir for CMV prophylaxis or treatment in thoracic organ transplant recipients

Background Cytomegalovirus (CMV) infection is common in thoracic organ transplant recipients. Valganciclovir and ganciclovir are used for both prophylaxis and treatment of this infection, but intolerance and treatment failure are common. Letermovir has been demonstrated to reduce the risk of CMV infection when used for prophylaxis in allogeneic hematopoietic cell transplantation. However, there are no data on its efficacy in thoracic organ transplantation. Methods We examined the use of letermovir for either CMV prophylaxis (primary and secondary) or treatment in heart and lung transplant recipients at our institution from February 1, 2018, through December 31, 2018. Results Nine total patients received letermovir at our institution (8 lung transplant, 1 heart transplant) during the study period. Letermovir was prescribed for CMV prophylaxis in eight patients (primary prophylaxis in two patients and secondary prophylaxis in 6 patients), and for treatment of CMV DNAemia in two cases. One patient received letermovir for both secondary prophylaxis and treatment on separate occasions. Three out of 8 (37.5%) patients receiving letermovir for prophylaxis developed CMV DNAemia during prophylaxis. One patient treated for CMV disease had clinical failure with a sharp rise in serum CMV DNA PCR. The other patient treated for low-grade CMV DNAemia initially had a slight rise in CMV DNA PCR, but has since had a sustained response. No major side effects were experienced, and 2 patients reported minor side effects. Conclusion Letermovir was well tolerated with only minor side effects reported; however, the rate of development of CMV DNAemia on prophylaxis was considerable. Further study of the dosing and efficacy of letermovir for CMV prophylaxis or treatment in thoracic organ transplant recipients is warranted.