Regdanvimab Treatment of COVID-19.

Dear Editor:

We would like to correspond and share ideas on the publication “Real world experience with regdanvimab treatment of mild-to-moderate coronavirus disease-19 in a COVID-19 designated hospital of Korea [1].” In conclusion, our real-world investigation reveals that regdanvimab treatment of mild-to-moderate COVID-19 considerably slowed disease development; however, the benefit seemed to wane during the Delta variant-dominant wave, according to Hong et al. To investigate the effects of regdanvimab in the period of Omicron dominance and large numbers of vaccinated persons, a large-scale prospective investigation or randomized clinical trial is required [1]. We agree that there might be clinical role of regdanvimab in COVID-19 therapy. In terms of mechanism, it prevents viral spike proteins from interacting with angiotensin-converting enzyme 2 (ACE2), which permits the virus to enter the cell. The current report tried based to control the confounding factors due to demographic background and the concurrent medical problem. It is expected that there should be a controlling of confounding factor from additional alternative therapy for management of infection in each COVID-19 case. Further issue that should be discussed is the impact of genetic polymorphism. Pathophysiologically, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) disrupts the ACE/ACE2 balance and activates the renin-angiotensin-aldosterone system (RAAS), leading to COVID-19 development, particularly in individuals with comorbidities such hypertension, diabetes, and cardiovascular disease [2]. As a result, ACE2 expression could have contradictory consequences, boosting SARS-CoV-2 pathogenicity while also reducing viral infection [2]. Severity of the infection is reported for association with genetic polymorphism of ACE2 [3]. Therefore, the impact of ACE2 genetic polymorphism might exist and this is an interesting issue for further study in assessment efficacy of the new drug, regdanvimab.