Effectiveness and Safety of Regdanvimab in Patients With Mild-To-Moderate COVID-19: A Retrospective Cohort Study

Safety and Effectiveness of Regdanvimab for COVID-19 Treatment: A Phase 4 Post-marketing Surveillance Study Conducted in South Korea

INTRODUCTION

Regdanvimab, a neutralising monoclonal antibody (mAb) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), received approval for the treatment of coronavirus disease 2019 (COVID-19) in South Korea in 2021. The Ministry of Food and Drug Safety in South Korea mandate that new medications be re-examined for safety and effectiveness post-approval in at least 3000 individuals. This post-marketing surveillance (PMS) study was used to evaluate the safety and effectiveness of regdanvimab in real-world clinical care.

METHODS

This prospective, multicentre, phase 4 PMS study was conducted between February 2021 and March 2022 in South Korea. Eligible patients were aged ≥ 18 years with confirmed mild COVID-19 at high risk of disease progression or moderate COVID-19. Patients were hospitalised and treated with regdanvimab (40 mg/kg, day 1) and then monitored until discharge, with a follow-up call on day 28. Adverse events (AEs) were documented, and the COVID-19 disease progression rate was used to measure effectiveness.

RESULTS

Of the 3123 patients with COVID-19 infection identified, 3036 were eligible for inclusion. Approximately 80% and 5% of the eligible patients were diagnosed with COVID-19 during the delta- and omicron-dominant periods, respectively. Median (range) age was 57 (18-95) years, and 50.6% of patients were male. COVID-19 severity was assessed before treatment, and high-risk mild and moderate COVID-19 was diagnosed in 1030 (33.9%) and 2006 (66.1%) patients, respectively. AEs and adverse drug reactions (ADRs) were experienced by 684 (22.5%) and 363 (12.0%) patients, respectively. The most common ADR was increased liver function test (n = 62, 2.0%). Nine (0.3%) patients discontinued regdanvimab due to ADRs. Overall, 378 (12.5%) patients experienced disease progression after regdanvimab infusion, with extended hospitalisation/re-admission (n = 300, 9.9%) as the most common reason. Supplemental oxygen was required by 282 (9.3%) patients. Ten (0.3%) patients required intensive care monitoring and 3 (0.1%) died due to COVID-19.

CONCLUSION

This large-scale PMS study demonstrated that regdanvimab was effective against COVID-19 progression and had an acceptable safety profile when used in real-world clinical practice.

Loss of Neutralizing Activity of Tixagevimab/Cilgavimab (Evusheld™) Against Omicron BN.1, a Dominant Circulating Strain Following BA.5 During the Seventh Domestic Outbreak in Korea in Early 2023

Tixagevimab/cilgavimab is a monoclonal antibody used to prevent coronavirus disease 2019 among immunocompromised hosts and maintained neutralizing activity against early omicron variants. Omicron BN.1 became a dominant circulating strain in Korea early 2023, but its susceptibility to tixagevimab/cilgavimab is unclear. We conducted plaque reduction neutralization test (PRNT) against BN.1 in a prospective cohort (14 patients and 30 specimens). BN.1 PRNT was conducted for one- and three-months after tixagevimab/cilgavimab administration and the average PRNT ND₅₀ of each point was lower than the positive cut-off value of 20 (12.9 ± 4.5 and 13.2 ± 4.2, respectively, P = 0.825). In the paired analyses, tixagevimab/cilgavimab-administered sera could not actively neutralize BN.1 (PRNT ND₅₀ 11.5 ± 2.9, P = 0.001), compared with the reserved activity against BA.5 (ND₅₀ 310.5 ± 180.4). Unlike virus-like particle assay, tixagevimab/cilgavimab was not active against BN.1 in neutralizing assay, and would not be effective in the present predominance of BA.2.75 sublineages.

Efficacy and safety of regdanvimab in patients with mild to moderate COVID-19: A rapid review and meta-analysis

AIMS

This study aimed to evaluate the efficacy and safety of regdanvimab, an anti-SARS-COV-2 monoclonal antibody approved by the European Medicines Agency in November 2021, for the treatment of confirmed COVID-19 disease.

METHODS

Cochrane Library, PubMed, medRxiv and Google Scholar were searched for relevant evidence up to October 27, 2022. The quality of included studies was assessed using the Cochrane risk of bias tools. Data were analysed using RevMan software.

RESULTS

Eight studies involving 4793 patients were included. A significant difference was observed between the regdanvimab and no-regdanvimab groups in terms of length of hospital stay (mean difference [MD] = -1.15, 95% confidence interval [CI]: -1.80 to -0.43), clinical recovery (odds ratio [OR] = 2.09, 95% CI: 1.38 to 3.18), disease progression (OR = 0.23, 95% CI: 0.16 to 0.33), the need for oxygen therapy (OR = 0.33, 95% CI: 0.25 to 0.43) and duration of oxygen therapy (MD = -3.00, 95% CI: -4.44 to -1.56). However, no significant difference was detected between 2 groups regarding mortality rate (OR = 0.46, 95% CI: 0.11 to 1.89), need for mechanical ventilation (OR = 0.39, 95% CI: 0.08 to 1.89) and hospital admission rate (OR = 0.61, 95% CI: 0.35 to 1.03). The incidence of adverse events was similar in both groups (OR = 0.96, 95% CI: 0.77 to 1.18).

CONCLUSION

Regdanvimab was not effective in reducing mortality and hospital admission rate in patients with mild to moderate COVID-19, but it was effective in improving other efficacy outcomes. Further research is needed to confirm these findings.

Use of the Monoclonal Antibody Regdanvimab to Treat Patients Hospitalized with COVID-19: Real-World Data during the Delta Variant Predominance

Regdanvimab is the only monoclonal antibody available in Korea that targets severe acute respiratory syndrome coronavirus 2. We retrospectively evaluated the clinical characteristics of 374 adults hospitalized with coronavirus disease 2019 (COVID-19) who were treated with regdanvimab from September through December 2021. In total, 322 (86.1%) patients exhibited risk factors for disease progression. Most patients (91.4%) improved without additional treatment. No patient died or was transferred to intensive care. This study shows that regdanvimab prevented disease progression in high-risk patients with mild to moderate COVID-19 infections during Delta variant predominance.