Effect of Regdanvimab on Mortality in Patients Infected with SARS-CoV-2 Delta Variants: A Propensity Score-Matched Cohort Study

Introduction: Regdanvimab, a monoclonal antibody pharmaceutical, is the first Korean drug approved for treating coronavirus disease 2019 (COVID-19). We analyzed the therapeutic efficacy of regdanvimab in patients with the COVID-19 delta variant infection.

Methods: We retrospectively reviewed the electronic medical records of patients hospitalized at two Korean tertiary COVID-19 hospitals with COVID-19 delta variant infection between May 26, 2021, and January 30, 2022. To analyze the therapeutic efficacy of regdanvimab, the patients were divided into regdanvimab and non-regdanvimab groups and were 1:1 propensity-score (PS)-matched on age, severity at admission, and COVID-19 vaccination history.

Results: Of 492 patients, 262 (53.3%) and 230 (46.7%) were in the regdanvimab and non-regdanvimab groups, respectively. After PS matching the groups on age, severity at admission, and COVID-19 vaccination history, each group comprised 189 patients. The 30-day hospital mortality rates (0.0% vs. 1.6%, p = 0.030), proportions of patients with exacerbated conditions to severe/critical/died (9.5% vs. 16.4%, p = 0.047), proportions who received oxygen therapy because of pneumonia exacerbation (7.4% vs. 16.4%, p = 0.007), and proportions with a daily National Early Warning Score ≥ 5 from hospital day 2 were significantly lower in the regdanvimab group.

Conclusions: We showed that regdanvimab reduced the exacerbation rates of conditions and mortality in patients with the COVID-19 delta variant infection. Thus, it is recommended to streamline the drug approval system during epidemics of new variant viruses to improve the availability and usage of therapeutics for patients. To facilitate this, relevant institutional support is required.