Azvudine versus Paxlovid for oral treatment of COVID-19 in Chinese patients with pre-existing comorbidities

Abstract: Journal of Infection 87 (2023) e24–e27 Contents lists available at ScienceDirect Journal of Infection journal homepage: www.elsevier.com/locate/jinf Letter to the Editor Azvudine versus Paxlovid for oral treatment of COVID-19 in Chinese patients with pre-existing comorbidities ]]]] ]] Dear Editor, Chinese guidelines grant the use of Azvudine and Paxlovid in COVID-19 patients, especially those with pre-existing comorbid­ ities.1,2 Recently, Gao Y et al. reported that Paxlovid appears to be superior to Azvudine in the virus clearance among general COVID-19 patients.3 However, a multicenter randomized controlled study de­ monstrated that Paxlovid showed no significant reduction in the risk of all-cause mortality on day 28 and the duration of virus clearance in hospitalized adult COVID-19 patients with pre-existing co­ morbidities.4 Several studies demonstrated that Azvudine could re­ duce the duration of virus clearance and improve the clinical prognosis in COVID-19 patients including those with pre-existing comorbidities.5–8 Therefore, concerns arise about the clinical effec­ tiveness of Azvudine versus Paxlovid in COVID-19 patients with preexisting comorbidities on admission. Here, we conducted a single-center, retrospective cohort study during the outbreak caused by the omicron from December 5, 2022 to January 31, 2023 in Xiangya Hospital of Central South University. The study included hospitalized patients with preexisting comorbidities and confirmed diagnosis of SARS-CoV-2 infection who received Paxlovid or Azvudine. The patients with these conditions were excluded: 1) younger than 18 years; 2) re­ ceived oxygen support or mechanical ventilation on the date of the admission; 3) not received any antiviral agents; 4) received both Azvudine and Paxlovid. The study was approved by the in­ stitutional review board of Xiangya Hospital of Central South University, and all the patients were anonymous and no need for individual informed consent. The primary endpoint was a composite disease progression outcome which was defined as any of the following events: 1) noninvasive respiratory support; 2) initiation of endotracheal intuba­ tion; 3) intensive care unit admission; 4) all-cause death. The sec­ ondary endpoints were each of these individual disease progression outcomes. Patients were observed from the date of admission until discharge, occurrence of outcome event or death, whichever came first. We used propensity-score models conditional on baseline characteristics, and the probability of receiving Azvudine was esti­ mated in an approach of calliper matching without replacement, with a calliper width of 0.2. The baseline covariates included age, sex, time from symptom onset to hospitalization, COVID-19 vacci­ nation status, severity of COVID-19 on admission (severe cases were defined as having respiratory rate ≥30, or oxygen saturation ≤93%, or PaO2/FiO2 ≤300 mmHg, or lung infiltrates > 50%), and concomitant treatments initiated at admission (systemic steroid and antibiotics). The standard mean differences (SMDs) were used to assess the balance of each baseline covariates between the groups before and after propensity-score matching which less than 0.1 indicating covariate was balanced.9 The incidence rates of outcome events were calculated as the number of outcome events / (sum of person × hospital days). Univariate Cox regression model was used to estimate a hazard ratio (HR) with 95% confidence interval (CI) for each..