This review aimed to synthesise the evidence related to the incidence of serious and non-serious adverse events with the use of monoclonal antibodies (mAbs) among COVID-19 patients.

Databases were searched from January 2020 to September 2023 for randomized clinical trials (RCTs) that used mAbs for the treatment of COVID-19 regardless of disease severity. Study screening, data extraction and data analysis were performed independently by two reviewers. The Cochrane risk of bias 1.0 tool was used for methodological quality assessment.

Sixteen studies were identified for analysis with 9682 participants in the intervention arm and 10 115 participants in the control arm. Seven trials reported hepatoxicity and there was a statistically significant increase in the chance of hepatoxicity among patients treated with mAbs compared to those given standard of care (SoC) or placebo with risk ratio (RR) = 1.70, 95% confidence interval (CI) 1.29-2.24. Five trials reported for neutropenia and there was a statistically significant association of neutropenia with the use of mAbs compared to SoC or placebo with RR = 4.03, 95% CI 1.74-9.34. Ten trials reported any disease-related serious adverse events related to the disease and there was a reduction of risk compared to SoC/placebo,  although this reduction was not statistically significant (RR = 0.88, 95% CI 0.70-1.11).

The use of mAbs was found to be associated with an increased risk of hepatoxicity and neutropenia compared to SoC/placebo among COVID-19 patients with moderate certainty of evidence. Long-term observational studies are recommended to observe post-COVID adverse events related to the use of mAbs.

Monoclonal antibodies (mAbs) have shown clinical benefits against coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Several studies have reported the use of bamlanivimab as a promising treatment option for COVID-19.

To synthesize the latest evidence for the efficacy and safety of bamlanivimab alone in the treatment of adult patients with COVID-19.

A literature search was conducted in PubMed, Cochrane Library, Web of Science, medRxiv, and Google Scholar using "SARS-CoV-2", "COVID-19", "LY-CoV555", and "Bamlanivimab" keywords up to January 25, 2023. The quality of included studies was assessed using the Cochrane bias tools. The Comprehensive Meta-Analysis software version 3.0 was used to analyze the data.

A total of 30 studies involving 47368 patients were included. A significant difference was observed between the bamlanivimab and standard of care/placebo groups in terms of mortality rate [risk ratio (RR) = 50, 95% confidence interval (CI): 0.36-0.70], hospitalization rate (RR = 0.51; 95%CI: 0.39-0.68), and emergency department (ED) visits (RR = 0.69; 95%CI: 0.47-0.99); while the two groups exhibited no significant difference in terms of intensive care unit (ICU) admission (P > 0.05). Compared to other mAbs, bamlanivimab was associated with a higher rate of hospitalization (RR = 1.44; 95%CI: 1.07-1.94). However, no significant difference was detected between the bamlanivimab and other mAbs groups in terms of mortality rate, ICU admission, and ED (P > 0.05). The incidence of any adverse events was similar between the bamlanivimab and control groups (P > 0.05).

Although the results suggest the efficacy and safety of bamlanivimab in COVID-19 patients, further research is required to confirm the efficacy of this drug for the current circulating SARS-CoV-2 variants.

Evidence on the effectiveness and safety of COVID-19 therapies across a diverse population with varied risk factors is needed to inform clinical practice.

To assess the safety of neutralizing monoclonal antibodies (nMAbs) for the treatment of COVID-19 and their association with adverse outcomes.

This retrospective cohort study included 167 183 patients from a consortium of 4 health care systems based in California, Minnesota, Texas, and Utah. The study included nonhospitalized patients 12 years and older with a positive COVID-19 laboratory test collected between November 9, 2020, and January 31, 2022, who met at least 1 emergency use authorization criterion for risk of a poor outcome.

Four nMAb products (bamlanivimab, bamlanivimab-etesevimab, casirivimab-imdevimab, and sotrovimab) administered in the outpatient setting.

Clinical and SARS-CoV-2 genomic sequence data and propensity-adjusted marginal structural models were used to assess the association between treatment with nMAbs and 4 outcomes: all-cause emergency department (ED) visits, hospitalization, death, and a composite of hospitalization or death within 14 days and 30 days of the index date (defined as the date of the first positive COVID-19 test or the date of referral). Patient index dates were categorized into 4 variant epochs: pre-Delta (November 9, 2020, to June 30, 2021), Delta (July 1 to November 30, 2021), Delta and Omicron BA.1 (December 1 to 31, 2021), and Omicron BA.1 (January 1 to 31, 2022).

Among 167 183 patients, the mean (SD) age was 47.0 (18.5) years; 95 669 patients (57.2%) were female at birth, 139 379 (83.4%) were White, and 138 900 (83.1%) were non-Hispanic. A total of 25 241 patients received treatment with nMAbs. Treatment with nMAbs was associated with lower odds of ED visits within 14 days (odds ratio [OR], 0.76; 95% CI, 0.68-0.85), hospitalization within 14 days (OR, 0.52; 95% CI, 0.45-0.59), and death within 30 days (OR, 0.14; 95% CI, 0.10-0.20). The association between nMAbs and reduced risk of hospitalization was stronger in unvaccinated patients (14-day hospitalization: OR, 0.51; 95% CI, 0.44-0.59), and the associations with hospitalization and death were stronger in immunocompromised patients (hospitalization within 14 days: OR, 0.31 [95% CI, 0.24-0.41]; death within 30 days: OR, 0.13 [95% CI, 0.06-0.27]). The strength of associations of nMAbs increased incrementally among patients with a greater probability of poor outcomes; for example, the ORs for hospitalization within 14 days were 0.58 (95% CI, 0.48-0.72) among those in the third (moderate) risk stratum and 0.41 (95% CI, 0.32-0.53) among those in the fifth (highest) risk stratum. The association of nMAb treatment with reduced risk of hospitalizations within 14 days was strongest during the Delta variant epoch (OR, 0.37; 95% CI, 0.31-0.43) but not during the Omicron BA.1 epoch (OR, 1.29; 95% CI, 0.68-2.47). These findings were corroborated in the subset of patients with viral genomic data. Treatment with nMAbs was associated with a significant mortality benefit in all variant epochs (pre-Delta: OR, 0.16 [95% CI, 0.08-0.33]; Delta: OR, 0.14 [95% CI, 0.09-0.22]; Delta and Omicron BA.1: OR, 0.10 [95% CI, 0.03-0.35]; and Omicron BA.1: OR, 0.13 [95% CI, 0.02-0.93]). Potential adverse drug events were identified in 38 treated patients (0.2%).

In this study, nMAb treatment for COVID-19 was safe and associated with reductions in ED visits, hospitalization, and death, although it was not associated with reduced risk of hospitalization during the Omicron BA.1 epoch. These findings suggest that targeted risk stratification strategies may help optimize future nMAb treatment decisions.

The therapeutic potential of sotrovimab in the treatment of coronavirus disease 2019 (COVID-19) is a controversial issue. The aim of this study was to evaluate the efficacy and safety of sotrovimab in COVID-19 patients. To this end, PubMed, Cochrane Library, Embase, Web of Science, medRxiv, and Google Scholar were searched up to 15 August 2022. The reference lists of key studies were also scanned to find additional records. Meta-analysis was performed using Comprehensive Meta-Analysis. Seventeen studies involving 27,429 patients were included. A significant difference was observed in mortality rate (odds ratio [OR] = 0.40; 95% CI: 0.25-0.63, p = 0.00), hospitalisation rate (OR = 0.53; 95% CI: 0.43-0.65. p = 0.00), hospital or death rate (OR = 0.43; 95% CI: 0.25-0.73, p = 0.00), the need for mechanical ventilation (OR = 0.57; 95% CI: 0.33-0.96, p = 0.03), and ICU admission (OR = 0.33; 95% CI: 0.17-0.67, p = 0.00) of the sotrovimab-receiving group compared to those having no sotrovimab. However, no significant difference was observed between the two groups in terms of disease progression (OR = 0.45; 95% CI: 0.16-1.24, p = 0.12) and emergency department visit (OR = 1.01; 95% CI: 0.83-1.24, p = 0.87). The two groups had no significant difference in terms of incidence of adverse events (OR = 0.98; 95% CI: 0.78-1.23, p = 0.88). The findings of the present meta-analysis support that sotrovimab could be an effective and safe treatment option to reduce mortality and hospitalisation rate in both Delta and Omicron Variants of COVID-19.