Efficacy of Antibody Cocktail Drug in COVID-19 Positive Patients: A Retrospective Single-centered Study

Introduction: Neutralising monoclonal antibodies (mABs) have been proposed and developed for the treatment of Coronavirus Disease-2019 (COVID-19) patients with mild to moderate diseases and to prevent further progression. The combination of Casirivimab and Imdevimab blocks the entry of virus into cells by attaching to receptor binding domain of Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2) spike glycoprotein. The mABs are utilised as a pre-emptive strategy in certain high-risk groups such as those suffering from chronic liver, kidney and respiratory disease, malignancies and other immunocompromised states where efficacy of vaccines may be suboptimal.

Aim: To evaluate the clinical outcomes in COVID-19 patients who were treated with Antibody Cocktail drug (casirivimab and imdevimab).

Materials and Methods: A retrospective observational study was conducted in patients confirmed positive for SARS-CoV-2 from June 2021 to January 2022 and subsequently, the collected data was analysed from May 2022 to June 2022. The study was conducted in a tertiary care referral hospital in eastern India. All eligible patient subsequently received casirivimab and imdevimab at COVID-19 facility. Monitoring of patients was done upto 12 hour postinfusion. Demographic parameters, routine investigations and clinical outcomes were assessed. Data entry was done using Microsoft excel. Data was entered, coded and analysed using International Business Machines (IBM) Statistical Package for the Social Sciences (SPSS) version 21.0. All analysis was done at a preset alpha error of 5% and results expressed at confidence levels of 95%.

Results: Total 104 eligible cases were taken in present study. Nearly, 93% of those patients who had not been vaccinated were at higher risk for having severely elevated levels of C-Reactive Protein (CRP) as compared to 48% of those with COVID-19 vaccination. Nearly, 9 out of 10 patients with moderate-severe CRP levels were at nine times more risk for longer duration of hospitalisation as compared to normal levels of CRP. All patients having moderate-severe CRP levels required mechanical ventilation in comparison to mild CRP levels. Patients with co-morbidities were more likely to get severe COVID-19 infections (p-value ≤0.05). Unvaccinated subjects were more likely to have severe infections than vaccinated subjects. (p-value ≤0.05). Prolonged hospitalisation (>7 days) was statistically significant in severe COVID-19. Unvaccinated subjects had a statistically significant rise in CRP over vaccinated subjects. The majority of the patients receiving antibody cocktail did not require prolonged hospitalisation while a minor fraction required invasive ventilation. Antibody cocktail was safe, well tolerated and had good efficacy and low mortality rate as compared to other modalities of treatment in this study.

Conclusion: The duration of hospitalisation and outcomes were superior in patients having mild to moderate COVID-19 who received antibody cocktail without any serious side-effects.