BACKGROUND: Data from a recent phase III clinical trial have demonstrated the efficacy of letermovir as cytomegalovirus (CMV) prophylaxis in adult CMV seropositive allogeneic HSCT recipients. Our objective was to assess the cost effectiveness of letermovir when compared to preemptive treatment in this population from the perspective of a third-party US payer.
METHODS: A decision-analytic model evaluated total cost and quality-adjusted life-years (QALY's) from a lifetime perspective. Efficacy data, including rates of CMV infection, CMV disease, rehospitalization, mortality, and quality of life were incorporated from clinical trial data at 24 weeks post-transplant (primary endpoint of the trial). Costs were obtained from published literature. Life-years during the first 24 weeks were estimated from the mortality seen in the clinical trial. Life-years post 24 weeks were estimated for the 24-week survivors by applying a relative risk of death for HSCT to the general mortality risk from the US Life Tables. Utility values were applied based on health status. Sensitivity analysis explored the impact of including data from the extended follow-up period, where some trial data was collected through 48 weeks post-transplant. The model used a discount rate of 3% annually.
RESULTS: In the base-case analysis, 1000 patients were followed until death. Letermovir reduced the number CMV infections requiring preemptive treatment (189 versus 443) at 24 weeks post-transplant. Prophylaxis with letermovir resulted in fewer cases of mortality (102 versus 159) and an increase in life-years (+481) and QALY's (+410), while increasing total cost from discharge to 24 weeks post-transplant. This resulted in an incremental cost-effectiveness ratio (ICER) of $29,110 per QALY gained. The sensitivity analysis using data from 48 weeks post-transplant did not have a significant effect on the results. Results of a probabilistic sensitivity analysis indicated that letermovir was cost effective in 93.5% of iterations at $100,000 per QALY gained and 95.2% of iterations at $150,000 per QALY gained.
CONCLUSIONS: The results of this model would suggest that letermovir is cost effective at commonly accepted ICER thresholds ($100,000 or $150,000 per QALY gained). The model inputs with a greatest impact on the results were a reduction in the rate of mortality and rehospitalization relative to a preemptive treatment strategy, and an increase in the cost of prophylaxis for letermovir.
