Monoclonal antibody bamlanivimab reduces hospitalization and death in moderate-to-severe COVID-19

By Angela Betsaida B. Laguipo, BSNMay 20 2021

Monoclonal antibody treatment may help prevent coronavirus disease (COVID-19) complications. Caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the infection has now caused over 164 million cases globally.

Researchers at the University of Pittsburgh School of Medicine and the University of Pittsburgh Medical Center found that monoclonal antibodies, a COVID-19 treatment administered early after infection, reduce the risk of hospitalization and death by 60 percent in people at high risk of suffering complications from the condition.

Published in the journal Open Forum Infectious Diseases, the team aimed to quantify the impact of bamlanivimab monoclonal antibody monotherapy on hospitalization and mortality among outpatients at high-risk COVID-19 complications.

Study: Impact of bamlanivimab monoclonal antibody treatment on hospitalization and mortality among non-hospitalized adults with SARS-CoV-2 infection. Image Credit: MattLphotography / Shutterstock

What are monoclonal antibodies?

Monoclonal antibodies are laboratory-produced molecules engineered to become substitute antibodies that can restore, enhance, and copy the immune system's attack on cancer cells and disease-causing pathogens.

In general, these antibodies bind to antigens that are found on the surface of cancer cells or pathogens, as opposed to healthy cells.

How do monoclonal antibodies work? The body's immune system produces antibodies to defend against unfamiliar molecules, called antigens. Molecules from viruses and bacteria act as antigens, triggering the production of antibodies.

These antibodies bind to antigens to kill them and ward off infection.  In SARS-CoV-2 infection, the body produces antibodies to the SARS-CoV-2 virus. Scientists have found that these antibodies can persist up to about seven months after infection.

From there, scientists can develop monoclonal antibodies by exposing white blood cells to a particular antigen in the laboratory. They can create many identical copies of the monoclonal antibody.

Monoclonal antibodies are given through a one-time intravenous (IV) infusion, which should be administered within ten days of COVID-19 symptom onset and diagnosis for patients who are more likely to progress to severe COVID-19. These include those over 65 years old, obese, or those with underlying health conditions such as lung disease, cardiovascular disease, or diabetes.

Bamlanivimab monoclonal antibody therapy

Bamlanivimab is a monoclonal antibody developed by AbCellera Biologics and Eli Lilly as a treatment for COVID-19. In November 2020, the U.S. Food and Drug Administration granted an emergency use authorization (EUA).

Between November 2020 and February 2021, four monoclonal antibodies were granted EUA from FDA. The drug is authorized for people with positive results of SARS-CoV-02 testing who are 12 years old and above, weighing at least 40 kilograms, and who are at high risk of progressing to severe COVID-19 or hospitalization.

In the current study, the researchers compared outpatients who received bamlanivimab monoclonal antibodies between December 9, 2020, and March 3, 2021, with non-treated patients.

The team considered factors like hospitalizations, mortality, and Emergency Department (ED) visits among patients at a high risk of progressing to severe COVID-19. Further, the team explored whether patient age, body mass index (BMI), and timing of treatment affected the link between monoclonal antibody treatment and outcome.

Researchers found that bamlanivimab treatment reduced the risk of hospitalization or mortality within 28 days. It was also associated with a lower risk of hospitalization or emergency department visits.

The researchers observed that the most substantial effect was seen in the elderly. Patients who are over 65 years old and received monoclonal antibodies were about three times less likely to be admitted to the hospital or die in the following month than untreated patients.

"If there's one key takeaway that we see in our data, it's this: If you get COVID-19 and are at higher risk for severe illness, ask your doctor about monoclonal antibodies," Dr. Graham Snyder, medical director of infection prevention and hospital epidemiology at UPMC and associate professor in Pitt's School of Medicine, said.

"Don't hesitate. Early treatment, while your symptoms are still mild, maybe essential," he added.

The study results encourage providers who are still hesitant to provide COVID-19 monoclonal antibodies. Also, the results can urge further studies and evaluation into the best patient groups to benefit from these treatments.