Cost-effectiveness analysis of the use of letermovir for the prophylaxis of cytomegalovirus in adult cytomegalovirus seropositive recipients undergoing allogenic hematopoietic stem cell transplantation in Italy

Background: The aim of the analysis is to assess the efficiency of the allocation of economic resources related to the use of letermovir cytomegalovirus (CMV) prophylaxis in adult seropositive recipients (R+) patients receiving an allogenic hematopoietic stem cell transplantation (HSCT), compared with a no-prophylaxis strategy, assuming preemptive antiviral administration in both groups from the perspective of the Italian National Health Service (NHS), through a cost-effectiveness analysis. Methods: The model used is based on a decision tree which simulates on a lifetime horizon the progression of CMV infection, considering two alternatives: the use of letermovir CMV prophylaxis, followed by preemptive therapy in case of clinically significant CMV infection, or the avoided use of letermovir CMV prophylaxis, considering direct medical costs (referred to 2018) and quality-adjusted life years (QALYs), both discounted considering a 3% annual rate. Two scenarios were considered, representing the differences related to regional contexts and clinical practice of different typologies of hospitals (public or private accredited with Regional Health Services). Results: The use of letermovir prophylaxis compared with no prophylaxis strategy would lead to an increase of QALYs and direct medical costs in the two scenarios considered, with a mean increase of 0.45 QALYs, and an increase of direct medical costs of 10,222.4 € and of 10,809.9 € in the two scenarios. The incremental cost-effectiveness ratios are equal to 22,564 €/QALY and 23,861 €/QALY. The probabilistic sensitivity analysis conducted showed a percentage of results below the threshold of 40,000 €/QALY of 67.4% and 71.3%; and below a threshold of 25,000 €/QALY equal to 50.4% and to 53.0%. Conclusions: The use of letermovir CMV prophylaxis in adult R+ patients receiving allogenic HSCT, compared with a no-prophylaxis strategy, would be cost-effective for the Italian NHS considering the incremental cost-effectiveness thresholds of 40,000 €/QALY and of 25,000 €/QALY.