Real-World Effectiveness Study of Nirmatrelvir-Ritonavir or Molnupiravir in Hospitalized Unvaccinated Patients with Chronic Respiratory Diseases and Moderate COVID-19 at Presentation

Abstract

<p><strong>Introduction:</strong> Nirmatrelvir-ritonavir (NMV-r) and molnupiravir (MOL) were developed as out-patient anti-viral for mild COVID-19. There was limited data on their role in treating COVID-19 for hospitalized patients, especially among adult patients who are unvaccinated and had chronic respiratory diseases.<br><strong>Methods:</strong> A territory-wide retrospective study was conducted in Hong Kong to compare the efficacy of NMV-r and MOL against COVID-19 in unvaccinated adult patients with asthma, chronic obstructive pulmonary disease, bronchiectasis and interstitial lung diseases presenting with moderate COVID-19 from 16th February 2022 to 15th March 2023.<br><strong>Results:</strong> A total of 1354 patients were included, 738 received NMV-r and 616 received MOL. NMV-r was more effective in reducing 90-day mortality with adjusted hazard ratios (aHR) of 0.508 (95% confidence interval [CI] = 0.314– 0.822, p = 0.006). Patients who received NMV-r also had significantly shorter length of stay (LOS) than those receiving MOL, with median LOS of 4 (Interquartile range [IQR] = 2– 7) for NMV-r and 6 (IQR = 3– 10) for MOL (p-value < 0.001). There was no statistically significant difference in the development of respiratory failure and severe respiratory failure in the two groups.<br><strong>Discussion:</strong> NMV-r was more effective than MOL among unvaccinated adults with chronic respiratory diseases who were hospitalized for moderate COVID-19 without hypoxaemia on admission.<br></p>