The impact of neutralizing monoclonal antibodies on the outcomes of COVID-19 outpatients: A systematic review and meta-analysis of randomized controlled trials.

To assess the clinical efficacy and safety of neutralizing monoclonal antibodies (mABs) for outpatients with coronavirus disease 2019 (COVID-19). PubMed, Embase, Web of Science, Cochrane Library, ClinicalTrials.gov, and World Health Organization International Clinical Trials Registry Platform (ICTRP) databases were searched from inception to July 19, 2021. Only randomized controlled trials (RCTs) that assessed the clinical efficacy and safety of neutralizing mABs in the treatment of COVID-19 outpatients were included. The Cochrane risk-of-bias tool was used to assess the quality of the included RCTs. The primary outcome was the risk of COVID-19-related hospitalization or emergency department (ED) visits. The secondary outcomes were the risk of death and adverse events (AEs). Five articles were included, in which 3309 patients received neutralizing mAB and 2397 patients received a placebo. A significantly lower rate of hospitalization or ED visits was observed among patients who received neutralizing mABs than those who received a placebo (1.7% vs. 6.5%, odds ratios (OR): 0.26; 95% confidence interval (CI): 0.19-0.36; I 2  = 0%). In addition, the rate of hospitalization was significantly lower in the patients who received neutralizing mABs than in the control group (OR: 0.24; 95% CI: 0.17-0.34; I 2  = 0%). The mortality rate was also significantly lower in the patients who received neutralizing mABs than in the control group (OR: 0.16; 95% CI: 0.05-0.58; I 2  = 3%). Neutralizing mABs were associated with a similar risk of any AE (OR: 0.81; 95% CI: 0.64-1.01; I 2  = 52%) and a lower risk of serious AEs (OR: 0.37; 97% CI: 0.19-0.72; I 2  = 45%) compared with a placebo. Neutralizing mABs can help reduce the risk of hospitalization or ED visits in COVID-19 outpatients. For these patients, neutralizing mABs are safe and not associated with a higher risk of AEs than a placebo.