Real-world Efficacy of Ensitrelvir in Hospitalized Patients with COVID-19 in Japan: A Retrospective Observational Study
Background: The coronavirus disease 2019 (COVID-19) pandemic necessitates continuously evaluating antiviral treatments, especially for high-risk groups, including older individuals. This study aimed to compare the e cacy of three antiviral drugs, including remdesivir, molnupiravir, and ensitrelvir, in hospitalized patients, focusing on outcomes such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen levels, hospitalization duration, and fever resolution. Methods: This retrospective observational study was conducted at Yoshida Hospital, Asahikawa city, Japan, enrolling 154 patients who received antiviral treatment upon COVID-19 diagnosis from July 1, 2022 to September 15, 2023. The diagnosis was con rmed by proprietary antigen tests or loop-mediated isothermal ampli cation assays. Patients who received treatment outside the hospital or with consistently negative antigen results were excluded. Drug administration was determined by attending physicians, considering oral administration challenges and renal dysfunction. The data were statistically analyzed using an unpaired two-tailed Student's t-test and one-way analysis of variance complemented by the Tukey post-hoc test for detailed group comparisons. Results: No signi cant differences were observed in the initial antigen levels among the treatment groups. By day 10, the ensitrelvir group showed lower antigen levels than did the other groups, but not signi cantly. The ensitrelvir group had a higher antigen-negative conversion rate and a signi cantly shorter hospital stay than did the molnupiravir group. However, no signi cant differences were noted in the fever resolution time among the groups. Conclusion: This study suggests the potential bene ts of ensitrelvir in reducing antigen levels and hospitalization duration. However, the overall e cacy of the antiviral agents for symptomatic relief appears similar. These ndings underscore the need for further research to optimize COVID-19 management by considering personalized treatment approaches and long-term outcomes.
Abbreviations The study protocol was approved by the Institutional Review Board of Yoshida Hospital (approval no. 20230809003) and conducted in accordance with the principles of the Declaration of Helsinki. Informed consent was obtained from all study patients using the opt-out method.
Consent for publication Not applicable.
Availability of data and materials The datasets used and/or analyzed in the current study are available from the corresponding author on reasonable request.
Competing interests The authors declare that they have no competing interests. Author contributions RY analyzed the data and was a major contributor in writing the manuscript. TS contributed to the manuscript by reviewing and editing the content and also played a supervisory role in the overall project. YO was responsible for the conceptualization of the project and managed the project administration. Duration before an admission temperature of >37 °C decreased to <37 °C with antiviral treatments.
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