Cost-Effectiveness of Oral Nirmatrelvir/Ritonavir in Patients at High Risk for Progression to Severe COVID-19 in the United States

Objectives:Nirmatrelvir/ritonavir (NMV/r) is an orally administered antiviral indicated for the outpatient treatment ofpatients with mild-to-moderate COVID-19 at high risk for disease progression to severe illness. We estimated the cost-effectiveness of NMV/r versus best supportive care for patients with mild-to-moderate COVID-19 at high risk forprogression to severe illness from a US health sector perspective. Methods:A cost-effectiveness model was developed using a short-term decision-tree (1 year) followed by a lifetime 2-stateMarkov model (alive and dead). The short-term decision-tree captured costs and outcomes associated with the primaryinfection and healthcare utilization; survivors of the short-term decision-tree were followed until death assuming USquality-adjusted life years (QALYs), adjusted in the short-term for survivors of mechanical ventilation. Baseline rate ofhospitalization and NMV/r effectiveness were taken from an Omicron-era US real-world study. Remaining inputs wereinformed by previous COVID-19 studies and publicly available US sources. Sensitivity analyses were conducted for allmodel inputs to test the robustness of model results.Results:NMV/r was found to decrease COVID-19 related hospitalizations (20.027 per infected case) increase QALYs (10.030),decrease hospitalization costs (2$1110), and increase total treatment cost (1$271), resulting in an incremental cost-effectiveness ratio of $8931/QALY. Results were most sensitive to baseline risk of hospitalization and NMV/r treatmenteffectiveness parameters. The probabilistic analysis indicated that NMV/r has a.99% probability of being cost-effective ata $100 000 willingness-to-pay threshold. Conclusions:NMV/r is cost-effective vs best supportive care for patients at high risk for severe COVID-19 from a US healthsector perspective