547. Molnupiravir and Nirmatrelvir/Ritonavir Effectiveness in Reducing the Risk for COVID-19 Disease Progression and Death

• Published in: Open forum infectious diseases 2023-11, Vol.10 (Supplement_2)
• Main Authors: Paraskevis, Dimitrios, Gkova, Mary, Mellou, Kassiani, Gkolfinopoulou, Kassiani, Kostaki, Evangelia Georgia, Loukides, Stylianos, Kotanidou, Anastasia, Skoutelis, Athanasios, Thiraios, Eleftherios, Saroglou, George, Zografopoulos, Dimitrios, Mossialos, Elias, Zaoutis, Theoklis, Gaga, Mina, Antoniadou, Anastasia, Tsiodras, Sotirios
• Format: Article
• Language: English
• ISSN: 2328-8957; 2328-8957
• DOI: 10.1093/ofid/ofad500.616

Abstract Background Molnupiravir (M) and Nirmatrelvir/Ritonavir (N/R) have been authorized for use in COVID-19 patients at high risk for severe disease. We aimed to evaluate the effectiveness of M and N/R in highly vulnerable SARS-CoV-2 patients using a retrospective cohort study design. Methods The study population consisted of SARS-CoV-2 infected non-hospitalized patients in Greece, aged 65 years or older, that received M between February 2 and March 25, 2022 and N/R between March 26 and July 20, 2022. The impact of each drug was determined via comparisons with age-matched control groups of SARS-CoV-2-positive patients who did not receive oral antiviral therapy, using as outcome (i) hospital admission with COVID-19 within 10 days after tested positive, and (ii) death from COVID-19 within 35 days from positive test. Results Overall, 4,240 M and 13,861 N/R recipients were enrolled. Administration of M significantly reduced the risk of hospitalization (Odds Ratio [OR] = 0.40, p < 0.001) and death (OR = 0.31, p < 0.001) among these patients based on data adjusted for age, previous SARS-CoV-2 infection, vaccination status, and time elapsed since the most recent vaccination. The reductions in risk were most profound among elderly patients (≥75 years old) and among those with high levels of drug adherence. Administration of N/R also resulted in significant reductions in the risk of hospitalization (OR = 0.31, p < 0.001) and death (OR = 0.28, p < 0.001). Similar to M, the impact of N/R was more substantial among elderly patients and in those with high levels of drug adherence. Conclusion N/R and M use prevented hospital admissions and death in a large real-world study of highly vulnerable patient populations. Disclosures All Authors: No reported disclosures