A: Short answer: Yes.
For people with COVID-19 infections who do not need to be hospitalized and who are at high risk of progressing to severe illness, monoclonal antibody therapies can reduce the risk of hospitalization and death. For the long answer, keep reading!
Monoclonal antibody therapies use laboratory made antibodies that are similar to the ones your body would make if you had the COVID-19 infection. These antibodies target the spike protein of the SARS-CoV-2 virus and stop the virus from entering the cells and making more copies of itself. The US Food and Drug Administration (FDA) has issued emergency use authorizations for several monoclonal antibody treatments: the combination of casirivimab and imdevimab, the combination bamlanivimab and etesevimab, and sotrovimab. These treatments are not available to everyone but are authorized for use in people diagnosed with mild to moderate COVID-19 (they don’t need to be in the hospital) and who are at high risk of developing severe disease. Currently, the combo therapy bamlanivimab/etesevimab is not recommended in the US because of decreased efficacy against some of the circulating variants (like Gamma and Beta).
I can hear you from home shouting into your computers: “Show me the evidence!” Ok! Hold your horses, but I applaud your enthusiasm!
First up: sotrovimab. The data supporting the use of sotrovimab came from the Phase 3 COMET-ICE trial (good name, right?). This trial included 583 people with mild to moderate COVID-19 randomized either to sotrovimab or placebo. All participants had a risk factor for worsening disease. The trial looked at how many participants were hospitalized or died from any cause within 29 days of randomization. Three of the 291 participants who got sotrovimab either died or were hospitalized compared to 21 of the 292 participants who got the placebo. That is a 6% absolute risk reduction in the combined endpoint of hospitalization and death. To put it another way, we would need to treat about 17 people with sotrovimab to prevent one case of hospitalization or death (this is called the number needed to treat, or NNT). That’s pretty darn good. Sotrovimab is still effective against the variants because it targets a part of the spike protein that has not mutated, so it maintains that neutralizing activity we are going for (Wooo!).
Next up: the combination of casirivimab and imdevimab. The data supporting the use of casirivimab/imdevimab comes from a Phase 3 double blind clinical trial (called R10933-10987-COV-2067 study, which we can all agree is not a cool trial name). In this trial, 736 people with at least one risk factor who had mild to moderate COVID-19 received casirivimab/imdevimab and 738 received placebo. Just like the COMET-ICE trial, the trial looked at hospitalization and death. 1% of the study group were hospitalized or died, compared to 3.2% in the placebo group. This is a 2.2% absolute risk reduction. We would need to treat about 45 people with casirivimab/imdevimab to prevent one case of hospitalization or death.
Great, you say. But who can get these?
The US FDA has granted emergency use authorization for people age 12 and up who have COVID-19, don’t need to be in a hospital, and have risk factors for getting really sick. Risk factors include older age, being overweight or obese, chronic diseases (like kidney, heart, or lung diseases), weakened immune systems, diabetes, or pregnancy. This is not an exhaustive list, as many different things (including other social determinants of health like where you live or work and the impacts of structural racism) can impact your risk of getting really sick. Treatment should be started as soon as possible after getting a positive test and within 10 days of your first symptom. Talk with your primary care clinician to see if you might benefit from monoclonal antibody therapies.
Do I have to go to an ER to get this treatment?
Nope! These treatments are given through an IV and can be administered anywhere that is set up to do that. Many doctor’s offices, infusion centers, and hospitals can give these. In the US, there is a website to help you find one of these sites (see below!).
What should I expect if I get one of these treatments?
The infusion takes about an hour to give and then you are watched closely for another hour to make sure that you are doing ok. Common side effects include feeling sick to your stomach, dizziness, rash, itching, and headache. Anaphylaxis (a severe allergic reaction) is rare but possible, which is why you get watched for a bit after the IV stops running.
Monoclonal antibodies aren’t a magic answer. People who get monoclonal antibody treatments still need to isolate and take steps to protect others from infection. They should look out for any signs of worsening illness (like trouble breathing, feeling confused, or chest pain) and seek medical help if symptoms are getting worse. People who got monoclonal antibody treatments should wait 90 days to get the COVID-19 vaccine.
There you have it! The quick and dirty (or not so quick?) of monoclonal antibody treatments for COVID-19.
Lots of Love,
The Nerdy Girls