Psy97 - Cost-Effectiveness Analysis of Enzyme Replacement Therapy for Type 1 Gaucher Disease

Abstract

OBJECTIVES: Data from a recent clinical trial (PN001) has demonstrated the efficacy of letermovir as prophylaxis of cytomegalovirus (CMV) reactivation and disease in adult CMV-seropositive recipients [R+] of an allogeneic haematopoietic stem cell transplant (HSCT). The objective of this cost-effectiveness analysis is to evaluate the clinical and economic value of letermovir compared to pre-emptive treatment from the payer perspective in England. METHODS: A decision-analytic model evaluated total costs and lifetime QALYs from the perspective of the NHS and personal and social services in England. Efficacy data included in the model were incorporated from PN001 at the time of primary endpoint assessment (24 weeks post-transplant). Costs of trial outcomes were obtained from published sources. Life-years were estimated from mortality observed in the clinical trial and were estimated for the week 24 survivors by applying a relative risk of death to the general population. Utility values were based on EQ-5D data. The annual cost to treat 1-year survivors was based on a proportion of patients receiving treatment for chronic graft-versus-host disease. Sensitivity analysis explored the impact of including data from the extended follow-up period (48 weeks post-transplant). The model used an annual discount rate of 3.5%. RESULTS: In the base-case analysis, letermovir reduced the number of CMV infections requiring pre-emptive treatment vs standard of care (SoC) (20.0% vs 49.3%) at 24 weeks post-transplant. Letermovir prophylaxis resulted in lower all-cause mortality at week 24 in comparison to SoC (10.2% vs. 15.9%), and a mean increase in QALYs (+0.46) and total costs per patient. Results of a probabilistic sensitivity analysis indicated that letermovir was cost effective in 81.9% of iterations at £20,000 per QALY gained and 89.5% of iterations at £30,000 per QALY gained. CONCLUSIONS: The results of this model suggest that CMV prophylaxis with letermovir is a cost-effective strategy at commonly accepted ICER thresholds.