Effectiveness of Remdesivir and in Combination with Dexamethasone among Hospitalized COVID-19 Patients in Hong Kong

Abstract

Introduction and Project Objectives: Evidence on the significant benefits of remdesivir and its combination with dexamethasone on mild-to-moderate COVID-19 patients is insufficient. Our research aims to investigate the disease progression, various clinical outcomes, changes in viral load, and duration of hospital stay associated with early remdesivir treatment as well as introducing remdesivir on top of dexamethasone among COVID-19 patients. Methods: A territory-wide retrospective cohort of >10400 patients hospitalized with confirmed COVID-19 infection from 21st January 2020 to 31st January 2021 in Hong Kong SAR, China was analyzed. Early remdesivir treatment was evaluated using 352 patients who had initiated remdesivir within the first two days of admission, and 1,347 patients without early remdesivir treatment as controls at a 1:4 matching ratio. In addition, 466 patients with remdesivir use before or coinitiated with dexamethasone and 1078 patients who had received remdesivir after dexamethasone or only received dexamethasone treatment were selected to examine optimal timing of remdesivir initiation on top of dexamethasone use. Propensity-score matching or weighting were used to minimize residual confounding, and balance baseline covariates between exposure and non-exposure groups. Cox regression models estimated hazard ratios (HR) of event outcomes, while linear regression models examined the treatment effects on hospital length of stay (LOS). Results: During a 14-day median follow-up, early remdesivir treatment was associated with significantly shorter time to clinical improvement (HR=1.14, 95%CI 1.01-1.29, p=0.038) and positive IgG antibody (HR=1.50, 95%CI 1.31- 1.70, p<0.001), lower risk of in-hospital death (HR=0.58, 95%CI 0.34-0.99, p=0.045), significant shorter hospital LOS among survivor (-2.56 days, 95%CI -4.86 to -0.26, p=0.029), in addition to achieving low viral load quicker (HR=1.51, 95%CI 1.24-1.83, p<0.001). Among hospitalized patients receiving dexamethasone within 13-day median follow-up, initiation of remdesivir prior to or co-initiated with dexamethasone had shorter time to clinical improvement (HR=1.23, 95%CI 1.02-1.49, p=0.032) and positive IgG antibody (HR=1.22, 95%CI 1.02-1.46, p=0.029), lower risk of in-hospital death (HR=0.59, 95%CI 0.36-0.98, p=0.042), as well as shorter hospital LOS by 2.65 days among survivors when compared with those receiving remdesivir after dexamethasone or non-remdesivir users. Conclusion: For hospitalized COVID-19 patients with the moderate disease but not requiring oxygen therapy on admission, early remdesivir treatment could be a potentially effective choice. Among hospitalized patients receiving dexamethasone, early or co-initiation of remdesivir with dexamethasone demonstrated significant clinical benefits, and was associated with shorter time to clinical improvement and positive IgG antibody, lower risk of in-hospital death, in addition to significantly shorter length of hospital stay.