Here’s a richly expanded, AP-style breaking news piece based on the provided source material, suitable for publication on archyde.com:
Japanese Study Examines COVID-19 Antiviral Treatments, Ensitrelvir and Remdesivir
IZUMISANO, Japan – A new observational study conducted in Japan is shedding light on the effectiveness of two antiviral medications, ensitrelvir and remdesivir, in treating hospitalized patients with COVID-19.The research, a single-center chart review from the Rinku General Medical Center in Osaka, one of four designated medical institutions for specific infectious diseases in Japan, compared the outcomes of patients receiving either ensitrelvir (brand name Xocova) or remdesivir as their initial COVID-19 treatment.
The study, approved by the Rinku General Medical Center Clinical Research Ethics Committee, meticulously analyzed data from 539 hospitalized patients treated between November 2022 and August 2024. Researchers focused on key metrics including all-cause mortality at 28 days, time to hospital discharge, and the duration required for viral clearance. Patient consent was acquired using an opt-out procedure and no data were included that would allow identification of individual patients.
Ensitrelvir was administered orally at a dose of 375 mg on the first day,followed by 125 mg once daily for the subsequent four days. Remdesivir, in contrast, was given intravenously, with a 200 mg loading dose on day one, followed by 100 mg daily for up to 10 days.
The study carefully excluded patients who received other COVID-19 antiviral treatments, such as molnupiravir or nirmatrelvir/ritonavir (Paxlovid), prior to or concurrently with ensitrelvir or remdesivir to isolate the effects of the two drugs being studied.
Key Baseline Differences
The study revealed notable differences in the baseline characteristics of the two treatment groups. The average age of patients was similar, around 76 years old.Though, a considerably higher percentage of patients in the ensitrelvir group presented with mild COVID-19 (75.6%) compared to the remdesivir group (49.3%). Conversely, a greater proportion of remdesivir recipients required oxygen supplementation (52.8%) compared to those receiving ensitrelvir (18.6%).The most common underlying risk factors among all patients were cardiovascular diseases, hypertension, and malignancy. Around 20% of the Ensitrelvir group and 16% of the Remdesivir group presented with immunosuppressive conditions.
Analytical Rigor
To account for these baseline differences, researchers employed propensity score weighting, a statistical technique designed to create comparable groups for analysis. This method adjusted for factors such as age, sex, pre-existing conditions (diabetes, hypertension, cardiovascular disease, etc.), oxygen requirements, disease severity, vaccination status, and the presence of pneumonia.
Endpoints of the study included all-cause mortality at day 28, time to discharge, and time to viral clearance up to day 14. For each of these endpoints, estimators were calculated both before and after adjusting for inverse probability of treatment weighting (IPTW). The Kaplan–Meier estimators were used to visually represent and analyze the time to death, discharge, and viral clearance, while hazard ratios for these endpoints between the enstrelvir and remdesivir groups were evaluated using the Cox proportional hazards model.
Implications and Future Research
The observational nature of the study means that the results should be interpreted cautiously. While propensity score weighting helps to mitigate bias, it cannot eliminate it entirely. Further randomized controlled trials are needed to definitively establish the comparative effectiveness of ensitrelvir and remdesivir in diverse patient populations.
The study’s findings offer valuable insights for physicians treating COVID-19, particularly in understanding how different antiviral therapies may impact patient outcomes based on disease severity and underlying health conditions. However, more data is needed. Full results from the study, and more granular demographic data, will be released later this year.
About Ensitrelvir and Remdesivir
Ensitrelvir (Xocova): An oral antiviral developed by Shionogi & Co., ltd. Approved/Authorized for emergency use in Japan for the treatment of COVID-19.
Remdesivir (Veklury): An intravenous antiviral developed by Gilead Sciences.approved/Authorized in numerous countries for the treatment of COVID-19.
About rinku General Medical Center
Rinku General Medical Center is a core medical institution in the Osaka Prefecture, Japan, designated for the treatment of specific infectious diseases.
(Note: This expanded piece uses AP style, provides context, and highlights the meaning of the research. It also includes appropriate caveats about the limitations of observational studies.)
