Neutralizing Monoclonal Antibodies for COVID-19 Reduces ED Visits

On April 24, 2023, researchers published the results of a cohort study analyzing the effect of neutralizing monoclonal antibodies (nMABs) on patients with COVID-19, noting significantly improved outcomes. In addition to reducing the number of emergency department (ED) visits, investigators noted a reduction in hospitalizations and death.

The study used data from academic healthcare systems in four states: California, Minnesota, Texas, and Utah. The healthcare facilities funneled patient data into a centralized registry using the Observational Medical Outcomes Partnership model.

From the registry, investigators extrapolated data on 167,183 patients who tested positive for COVID-19 with a PCR or antigen test from November 9, 2020, to January 31, 2022. All patients included in the study had not initially been hospitalized and were 12 years old or older.

Additionally, researchers only included patients who fit one or more of the FDA’s criteria for high risk of poor outcomes. This patient population — including people 65 and older, pregnant individuals, obese patients, patients with certain chronic diseases, and immunocompromised patients — was the most likely to get nMAB treatment.

Over 25,200 patients included in this study were treated with nMABs, accounting for a relatively small proportion of patients.

A statistical analysis from the researchers revealed that nMAB treatment reduced the risk of an ED visit within two weeks of diagnosis by 24%. While that may not seem significant to many, patients who do not have to visit the ED reduce the risk of spreading or contracting other illnesses and help minimize the workload on physicians who are already overworked.

In the same vein, nMAB treatment also minimized the risk of hospitalization within 14 days of diagnosis. The treatment cut down hospitalization risk by nearly half, accounting for a 48% reduction in hospitalizations. Once again, reduced hospitalization rates may minimize the risks and workload associated with hospital visits.

Finally, the risk of death within 30 days of diagnosis was extraordinarily lower for patients treated with nMABs. The investigators noted an 86% reduction in death for nMAB-treated patients.

Beyond determining the general reduction in visits, hospitalizations, and deaths, the researchers also identified trends in treatment impact. For example, specific populations, including unvaccinated and extremely high-risk patients, benefited significantly more from the treatment.

Additionally, researchers noticed that patients who had nMAB treatment during the Delta variant period significantly reduced hospitalizations; however, those infected during the Omicron BA.1 epoch did not have improved hospitalization rates with nMAB treatment.

“This cohort study found that nMAbs for the treatment of COVID-19 were generally safe and associated with reductions in adverse outcomes, including ED visits, hospitalization, and death, with patients at greatest risk of severe COVID-19 complications benefiting most from treatment. These findings suggest that targeted risk stratification strategies may help optimize future nMAb treatment decisions,” concluded researchers in the study.

Despite the clinically useful data included in the publication, multiple limitations must be addressed. First, all patients in this study were over 12, meaning clinicians cannot rely on these results to support pediatric decision-making.

Moreover, the analyses conducted for this publication focused on White patients, as 83.4% of the patient population was White. With that in mind, the data carries little to no clinical significance for patients of other races. Additional research analyzing a more diverse patient population and long-term outcomes is vital before definitive conclusions are made regarding nMAB treatment.