In a recent study published in the Journal of Clinical Medicine, a team of researchers evaluated the effectiveness of regdanvimab on clinical outcomes in patients with mild to moderate coronavirus disease 2019 (COVID-19).
Remdesivir received the Food and Drug Administration (FDA) and the European Medicines Agency (EMA) Emergency Use Authorizations (EUA) in May 2020 and June 2020, respectively. Since then, several therapeutic options, including antiviral agents, monoclonal antibodies (mAbs), etc., have been developed to improve outcomes in COVID-19. However, given the limited treatment options, remdesivir and dexamethasone remain the most potent drugs for treating hospitalized COVID-19 patients requiring supplemental oxygen.
Several past studies have demonstrated that a mAb Regdanvimab reduces hospitalization in patients with mild to moderate COVID-19. Subsequently, in September 2021, it received approval from the Korean Ministry of Food and Drug Safety for use in patients at risk of progression to severe COVID-19. Despite being highly recommended, the data regarding its effectiveness and safety in clinical practice is sparse.
About the study
In the present retrospective observational study, the researchers enrolled 152 patients admitted to Armed Forces Goyang Hospital, South Korea, between August -October 2021 who were diagnosed with mild to moderate COVID-19.
Of these 152 study participants, 89 patients receiving regdanvimab formed the regdanvimab group, whereas 63 others formed the non-regdanvimab group. The researchers compared the clinical outcomes of regdanvimab usage in both the study groups, simultaneously investigating its safety profile.
They used a linear mixed-effects model (LMEM) to test the effectiveness of regdanvimab usage on symptom severity score (SSS) and the results of laboratory tests. The researchers conducted all the lab tests on hospital days (HDs) 1, 4, and 7 as routine clinical practice.; likewise, all the patients completed a questionnaire inquiring for SSS on these HDs to help researchers surveil COVID-19-related symptoms. The patients in the regdanvimab group were administered a single intravenous infusion of 40 mg/kg for 60 minutes by hospitalization day (HD) 2.
Further, using a multivariate logistic regression model, the researchers calculated the odds ratio (OR) for additional therapeutic options, such as remdesivir, dexamethasone, and supplemental oxygen, more specifically, the effect of regdanvimab usage on the initiation of these treatments. This model adjusted for all possible clinical variables, including age, sex, Charlson comorbidity index (CCI) score, vaccination status, body mass index, baseline body temperature, etc., and other variables between the regdanvimab and the non-regdanvimab groups.
The study findings revealed that compared to the non-regdanvimab group, the patients who received regdanvimab were older, showed a higher rate of vaccination, CCI score, baseline body temperature, and percentages of pneumonia at admission.
As demonstrated by LMEM analysis, the use of regdanvimab showed no interactive effects on the SSS and laboratory findings; however, its usage decreased the probability of requiring additional treatments. The need for dexamethasone, remdesivir, and oxygen supplementation after regdanvimab usage was 85.8%, 90.3%, and 89.8%, respectively. Additionally, older age, male sex, obesity, high initial body temperature, and the presence of pneumonia at admission were associated with increased ORs for the use of these additional treatments.
This finding is consistent with previous studies; for instance, in another study, regdanvimab usage reduced death, oxygen supplementation, and the need for intensive care unit care by 83.1%. However, it is possible that since the age of patients receiving regdanvimab was lower in the present study (46.9 vs. 61 years), slightly fewer patients showed severe disease progression.
In the regdanvimab and non-regdanvimab groups, LMEM analysis showed decreasing trends for creatinine, C-reactive protein, and lactate dehydrogenase. However, safety profiles based on laboratory testing showed no significant differences between these two groups.
The estimated SSSs of both respiratory and non-respiratory symptoms showed no association between regdanvimab usage and symptom improvement, as demonstrated by the LMEM model.
Several other mAbs have shown promise as a treatment for mild to moderate COVID-19, including a combination of bamlanivimab plus etesevimab, the REGN-COV2 antibody cocktail, to name a few. Even a lab-engineered mAb, Sotrovimab, has been shown to reduce the need for hospitalization or death in COVID-19 patients by 85%, with no safety concerns.
The present study demonstrated the potential of regdanvimab usage. It was well tolerated and decreased the probability of requiring remdesivir, dexamethasone, and oxygen therapy in mild to moderately ill COVID-19 patients. However, SSS was not significantly reduced by drug usage. It is worth noting here that a previous study has shown mitigation of clinical symptoms in regdanvimab-treated animals who were infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) D614G variant.
In the future, studies using larger sample sizes and a prediction model or a clustering algorithm based on machine learning might provide better insights into predicting patients who would specifically respond to the regdanvimab treatment.