Abstract
Background: Nirmatrelvir/ritonavir (NMV/r) and molnupiravir are oral antiviral drugs approved for the treatment of early symptomatic patients with mild to moderate COVID-19 at high risk of progression to severe disease in Japan. Objective: This study evaluated, from a Japanese payer perspective, the cost-effectiveness of NMV/r compared with molnupiravir among patients with COVID-19. Methods: This cost-effectiveness model describes the COVID-19 disease history and the impact of antiviral treatment on short-term and long-term outcomes. Nirmatrelvir/ritonavir was compared with molnupiravir, and in the scenario analysis NMV/r was compared with standard of care over a lifetime horizon. Results: When compared with molnupiravir, NMV/r showed higher quality-adjusted life years (QALYs) (15.752 vs 15.739) and higher total cost (¥6 248 014 vs ¥6 245 829 [US 44 136.86vs 44 121.42]). The incremental cost-effectiveness ratio was ¥164 934 (US 1165.12)perQALYgained, whichwaslowerthanthewillingness - to - pay(WTP)thresholdinJapan(¥5 000 000/QALY[US 35 320.71/QALY]). In the scenario analysis, the incremental cost-effectiveness ratio was ¥3 646 821 (US 25 761.66)perQALYgained.One - waysensitivityanalysisandprobabilisticsensitivityanalysisshowedthatNMV/rwascost - effectivecomparedwithmolnupiravirandstandardofcareconsistently.Allresultsofone - waysensitivityanalysisshowedthattheincrementalcost - effectivenessratioswerebelowtheWTPthresholdinJapan.Theresultofthecost - effectivenessacceptabilitycurveshowedthattheprobabilitythattheincrementalcost - effectivenessratiowasbelowtheWTPof¥5 000 000/QALY(US 35 320.71/QALY) was 100.00%. Conclusion: Nirmatrelvir/ritonavir is cost-effective compared with molnupiravir and standard of care from a Japanese payer perspective. This study provides evidence for the cost-effectiveness of NMV/r for patients with COVID-19.