Antibodies are our natural response to infection. They can be collected from the blood of recovered patients or – using modern technology – produced synthetically in a laboratory.
The idea of using antibodies as a medical treatment dates back to the 1
Nearly a century later, scientists Georges JF Koehler and Cesar Milstein learned to design cells that produced many copies of an antibody that could be used to treat disease in the 1970s. These drugs, known as monoclonal antibodies, use a concentrated, large number of identical antibodies to attack a very specific target.
The first monoclonal antibody was approved to reject kidney transplantation in the 1980s. By 2019, the Food and Drug Administration has approved 79 drugs with monoclonal antibodies.
“Antibodies make up some of the world’s most important drugs for anything from cancer to autoimmune disease,” said Dr. Elaine Lanning Prak, a professor of pathology at the University of Pennsylvania.
Medicines, sometimes called “biologicals,” treat a variety of ailments, ranging from cancer to eczema to certain types of arthritis. Humira, the brand version of the drug called adalimumab, was the best-selling drug in the world in 2018, bringing sales to drug maker AbbVie of $ 19.9 billion.
And last week, biotechnology company Regeneron – the same company that makes the drug Trump received – won FDA approval for the first treatment for Ebola, Inmazeb, a mixture of three monoclonal antibodies. These antibodies target parts of the outer protein that Ebola uses to attach to and infect human cells.
As for COVID-19, anti-antibody drugs – all of which are still experimental and have not yet been shown to work – block the virus’s ability to attach to the body’s cells and infect them. Companies such as Regeneron, Eli Lilly and AstraZeneca are currently being tested at a late stage.
“These antibodies are designed to bind to very specific sites of the SARS-CoV-2 protein,” explained Dr. Thomas Campbell, a physician at the University of Colorado School of Medicine who runs the Colorado COVID site for Regeneron-19. tests for the treatment of antibodies.
“It’s a way to provide you with quick protection when you’re already in trouble,” Prak said. Medications are designed to protect already infected patients when there is not enough time for the body to make its immune response.
Monoclonal antibody drugs are not the same as convalescent plasma, another high-profile experimental treatment with COVID-19. However, the treatment is similar, with both providing a shortcut to the body’s natural defenses against a foreign invader – a concept called passive immunity.
Convalescent plasma is a “mixture of hundreds or thousands of different antibodies” that targets multiple sites of the virus, according to Prak. Monoclonal antibody treatment has a high concentration of a single, specific antibody, which makes the drug stronger than reducing plasma.
These treatments, which are used for a wide range of diseases, are not without risk. Depending on where the antibodies bind in the body, the drugs can cause different effects. For example, the pharmaceutical company Genentech removed efalizumab, originally approved for the treatment of psoriasis, from the US market because in 2009 it was associated with a risk of fatal brain infections.
Another company, Janssen, stopped making drugs from synthetic antibodies in 2010, in part because of severe side effects – some of which are potentially fatal.
Although synthetic antibodies are currently being tested as a way to prevent COVID-19, in addition to treating the disease, researchers still don’t know if this type of drug can repel the virus. And they say that even if it works, the protection will probably only last a short time.
“If they only last a few weeks to a month, then they probably won’t be protective in six months or a year,” Campbell explained.
Alternatively, vaccines teach the body to recognize foreign invaders, such as the new coronavirus, and give the body longer-lasting immunity.
But experts say monoclonal antibodies could be a “bridge” to the vaccine and work in tandem with one to control the pandemic.
“The people who are most at risk for COVID are the ones who can get pretty bad vaccine reactions,” Prak said. “So, in this population, this kind of therapy can be very useful.”
Dr. Miranda Rosenberg is a resident of dermatology at the University of Miami and a contributor to the medical unit of ABC News.