A Comparison of the Adverse Effects and Utility of Different Monoclonal Antibodies for SARS-CoV-2: A Retrospective Cohort Study

Introduction Multiple monoclonal antibody (mAb) treatments have been developed to combat the growing number of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strains. These treatments have been shown to be effective in reducing the risk of hospitalization and death from SARS-CoV-2 infection with a low risk of adverse effects; however, more data is required to evaluate the comparative efficacy of mAbs. The primary objective of this study is to describe the hospitalization rate, length of stay (LOS), and mortality rate in SARS-CoV-2 patients treated with four different mAb treatments, including bamlanivimab plus etesevimab, casirivimab plus imdevimab, sotrovimab, and bebtelovimab. Methods A retrospective chart review and prospective phone surveys of SARS-CoV-2 patients treated with mAbs in a 400-bed tertiary, suburban medical center were conducted between June 2020 and April 2022. Eligibility criteria for mAbs included non-hospitalized patients over the age of 18 with less than 10 days of SARS-CoV-2 symptoms and no oxygen requirement on emergency department (ED) admission. Data were collected from the retrospective chart review and subjective patient surveys. A chi-squared test was used. Significance was assessed at p < 0.05. Results The study population included 3249 patients, with 1537 males and 1712 females and an average age of 62.48 ± 17.54 years. Five hundred forty-two patients received bamlanivimab plus etesevimab; 849 received bebtelovimab; 1577 received casirivimab plus imdevimab; and 281 received sotrovimab. The overall hospitalization rate was 1.0%, and the mortality rate was 0.2% following mAb treatment. The hospitalization rate was greatest among patients administered Sotrovimab (2.1%) and least among patients administered Bebtelovimab (0.1%) (p = 0.010). 2.4% of patients who were discharged from the ED after receiving one of the four mAbs returned within 30 days with SARS-CoV-2 symptoms. The average length of stay was 4.75 ± 4.56 days, with no significant differences between the mAbs. The provider-reported adverse event rate was 2.2%, with significant differences in adverse event rates between mAbs. Bamlanivimab-etesevimab was associated with the highest adverse event rate (4.6%), and sotrovimab was associated with the lowest adverse event rate (1.4%) (p < 0.001). Conclusion This study shows a low hospitalization and mortality rate following mAb infusion in patients with mild and moderate COVID-19. However, there were significant differences in hospitalization and mortality among patients receiving each of the four mAb treatments. There was a high degree of patient-reported symptom improvement, and adverse reactions were reported in only 2.2% of patients with no severe reactions. Multiple monoclonal antibody treatments are not effective as monotherapy; however, this study shows the potential benefits of including a mAb infusion as part of a SARS-CoV-2 treatment plan.