OBJECTIVES: Nirmatrelvir/ritonavir (NMV/r) and Molnupiravir (Mol) are oral antiviral drugs approved for treating COVID-19 in Japan. This study evaluated the cost-effectiveness of NMV/r compared with Mol among patients with mild-to-moderate COVID-19 who have risk factors for severe disease from a Japanese payer perspective over a lifetime horizon.

METHODS: The cost-effectiveness model used in this study comprised of a short-term decision tree (1 year) and a lifetime 2-state Markov model (alive and dead). The modeled results were reported as total costs, incremental costs, total quality-adjusted life years (QALYs), incremental QALYs, and incremental cost-effectiveness ratio (ICER). One-way sensitivity analysis and probabilistic sensitivity analysis were conducted to evaluate the robustness of the results. Scenario analysis was performed to compare NMV/r with standard of care (SoC).

RESULTS: When compared to Mol, NMV/r showed higher QALYs (15.566 vs. 15.544) and lower total cost (JPY 6,176,551 vs. 6,183,599 [USD 43,632.03 vs. 43,681.83]), indicating that NMV/r was dominant over Mol. Scenario analysis compared NMV/r to SoC showed that the ICER was JPY 1,928,169 [USD 13,620.86] per QALY, which was lower than the threshold in Japan (JPY 5,000,000/QALY [USD 35,320.71/QALY]).

CONCLUSIONS: NMV/r is dominant or cost-effective compared to Mol and SoC from a Japanese payer perspective. The findings of this study provide substantial evidence for the cost-effectiveness of NMV/r for patients with COVID-19 in Japan.