The Food and Drug Administration (FDA) has granted emergency use authorization (EUA) to sotrovimab for the treatment of mild to moderate COVID-19. This designation allows for the drug's use even though it has not yet been approved. Other monoclonal antibodies that have received EUA for COVID-19 treatment include bamlanivimab with etesevimab (authorized in February) and casirivimab with imdevimab (authorized in November 2020). The EUA for bamlanivimab when used alone was revoked in April, as variant COVID-19 strains were highly resistant to bamlanivimab monotherapy.

Sotrovimab is a monoclonal antibody that works directly against the spike protein of SARS-CoV-2, the virus that causes COVID-19, to block its attachment and entry into a human cell. The EUA allows sotrovimab to be used to treat mild to moderate COVID-19 in individuals ages 12 years and older who are at high risk for progression to severe illness, which increases the likelihood of hospitalization, the need for mechanical ventilation, and the possibility of death. According to the Centers for Disease Control and Prevention, patients at increased risk for moderate to severe COVID-19 include those over 65 years of age and those with cardiovascular disease, type 1 or 2 diabetes, chronic respiratory disease, cancer, chronic kidney disease, neurological conditions (like dementia), Down syndrome, HIV infection, an immunocompromised state, liver disease, overweight/obesity, pregnancy, sickle cell disease or thalassemia, a smoking history (current or past), solid organ or blood stem cell transplant, stroke or cerebrovascular disease, and substance use disorders. Factors such as race, ethnicity, and certain disabilities can also contribute to higher risk.

Sotrovimab should not be used in patients who are moderately to severely ill and hospitalized with COVID-19 or who require oxygen therapy, because monoclonal antibodies have not been shown to be effective in these populations and may worsen clinical outcomes.

The FDA granted EUA to sotrovimab based on a combination phase 1/2/3 randomized, double-blind, placebo-controlled clinical trial in 583 nonhospitalized adults with mild to moderate COVID-19 symptoms and a positive laboratory test for the virus. Half received sotrovimab and half received placebo within five days of symptom onset. The primary end point was progression of COVID-19-defined as hospitalization for more than 24 hours for acute management of any illness or death from any cause-through day 29. The primary end point was reached in 7% of those receiving placebo compared with only 1% of those treated with sotrovimab, an 85% reduction.

Because there are limited data on sotrovimab, unexpected or previously unreported adverse effects may occur. Hypersensitivity reactions were noted in trials, with both infusion-related reactions and anaphylaxis possible. Hypersensitivity reactions can occur more than 24 hours after infusion. Rash and diarrhea were also noted after sotrovimab treatment. Some patients who received sotrovimab experienced clinical worsening of COVID-19 illness. It is not yet known if this occurred as a result of normal disease progression or sotrovimab.

Nurses should confirm that their facility has immediate access to medications to treat a severe infusion reaction, such as anaphylaxis, and the ability to activate the emergency medical system as necessary. Patients must weigh at least 40 kg to be eligible for sotrovimab treatment, so nurses should confirm the weight of small patients prior to initiating therapy. Sotrovimab is administered as a 500-mg single IV dose. Nurses should gently swirl the single-use vial, avoiding the creation of bubbles, prior to withdrawing the 500 mg/8 mL dose. Sotrovimab should then be injected into a mini bag of normal saline (NS). The bag should not be inverted, but gently rocked back and forth by hand three to five times once it is hanging on the IV pole. Attaching a 0.2-micron polyethersulfone filter to the infusion set is strongly recommended. The infusion line should be primed with plain NS; the entire bag of diluted sotrovimab should then be infused over 30 minutes; sotrovimab should not be given as an IV push or bolus. The tubing should be flushed with plain NS to ensure that the entire sotrovimab dose has been administered. Patients should be monitored for at least an hour following infusion for hypersensitivity reactions.

Nurses can find more information in the fact sheets for health care providers (http://www.fda.gov/media/149534/download) and patients, parents, and caregivers (http://www.fda.gov/media/149533/download). To read the full EUA letter, see http://www.fda.gov/media/149532/download.

To read the FDANews Release regarding the EUA for sotrovimab, go to http://www.fda.gov/news-events/press-announcements/coronavirus-covid-19-update-f.