Monoclonal Antibodies: An Effective Treatment for COVID-19
The use of monoclonal antibody therapy has proven promising in the treatment of many diseases—for example, in carrying chemotherapy or radiation agents directly to cancer cells, or in reducing inflammation from rheumatoid arthritis, ulcerative colitis, Crohn’s disease, and other medical disorders.
And the good news for patients with early-stage COVID-19? Scientists have worked to develop a monoclonal antibody therapy that can fight the coronavirus, and certain treatment agents have been granted Emergency Use Authorization (EUA) from the US Food and Drug Administration (FDA).
The EUA has spurred healthcare organizations, including our team here at MedStar Health, to develop robust programs to administer these treatments. The currently authorized antibody treatments show promise, and we expect more and better treatments soon—treatments that will give us even stronger, more effective defenses against future pathogens, the bacteria and viruses that cause disease.
What Are Antibodies?
Antibodies are proteins, the substance of the body’s immune response. The body models its antibody proteins to recognize and target the unique protein signatures of certain pathogens, foreign invaders that infiltrate the bloodstream and attempt to break into healthy cells. When an antibody spots a pathogen, it grabs hold of the invader and sounds an alarm to activate other components of the immune system and destroy the pathogen.
Over time, as humans are exposed to various diseases, the body builds the antibodies it needs to fight them and retains them in case a disease tries to return. This is how we gain immunity to measles, mumps, chickenpox, and other diseases that generally appear once in a lifetime.
But making these antibodies takes time. The infecting pathogen can make us very sick until our body is able to make and deploy enough antibodies to fight back. With a new infectious disease like COVID-19, patients may suffer serious ill effects before their immune systems are able to mount an effective defense. And some people, of course, do not survive.
With antibody therapy, we’re able to give the body a shortcut, boosting its immune response by introducing antibodies that are pre-assembled and pre-programmed to fight the coronavirus.
Monoclonal antibody therapy can reduce the severity of COVID-19 for patients in the beginning stages of the virus. Details from Dr. Glenn Wortmann. https://bit.ly/30mDtDn via @MedStarWHC
Effective Treatment Approaches
The pathogens that present the greatest challenge to medicine are new ones like COVID-19, against which we have no immunity. This is why the novel coronavirus has spurred a global health pandemic—our bodies were not prepared to fight it.
Antibiotic drugs target bacteria directly and have changed world health for the better in many significant ways. But effective antivirals are harder to make. Viruses are composed of the same stuff as living cells but, unlike bacteria, they’re not a life form in the traditional sense. That makes them difficult to eliminate using drug therapy.
To treat an infectious disease like COVID-19, we can either target the virus directly or help the body develop its own defenses against it. Vaccines, antibody therapy, and plasma therapy all deliver more antibodies to our front line of defense, arming the body to fight the disease.
• Vaccines accomplish this by teaching the body to make antibodies. The newly introduced Johnson & Johnson therapy is a viral vector vaccine that uses a modified virus—one that’s different from the targeted virus—to serve as a carrier of the vaccine; it instructs the cells of the body to make a protein from the targeted virus.
On the other hand, COVID-19 vaccines from Pfizer and Moderna introduce a bit of synthetic genetic material, mRNA, to the body’s cells, enabling the cells to manufacture a harmless piece of COVID-19 protein.
In each of these vaccines, the particle introduced cannot cause illness, but instructs our own cells to make a virus protein so that the body’s immune system learns to recognize and block the real thing.
• In the case of plasma therapy, the blood plasma of a patient who successfully fought the pathogen is administered to another patient. The recipient’s immune system uses it to learn to fight the same pathogen.
• Monoclonal antibodies are laboratory-developed and have an effect similar to a vaccine in that antibodies are developed to boost our immunity. But instead of preventing infection by prompting the body to create new antibodies like a vaccine, the monoclonal antibodies are used to help treat an infection which has started.
Antibodies and COVID-19
Emergency use is granted to experimental drugs or drugs under development that are shown to be safe and demonstrate some level of effectiveness in clinical studies. In the study supporting emergency use of monoclonal antibodies, the patients who received the antibodies were slightly less likely to need hospitalization, compared with patients who did not receive them.
In November 2020, the FDA cleared two monoclonal antibodies for COVID-19 treatment: bamlanivimab, as well as a “cocktail” treatment of casirivimab and imdevimab. Both treatment approaches are currently available to early-stage COVID-19 patients at MedStar Washington Hospital Center, MedStar Southern Maryland Hospital Center, and MedStar Harbor Hospital.
FDA guidelines recommend monoclonal antibody treatment only for the following patients who have tested positive but who are not hospitalized due to COVID:
• 12 years or older
• Weigh more than 88 pounds
• Experiencing mild to moderate symptoms such as cough, fatigue, loss of appetite, and fever for fewer than 10 days
• At risk to get very sick from COVID-19
Currently, we have no real data on use of monoclonal antibodies to treat pregnant women who are sick with COVID-19. Consultation with a healthcare provider will help expectant moms to determine the best treatment approach, depending on individual risk factors.
Are there instances when antibodies are not recommended? Yes, antibodies have little effect if a patient’s case of COVID-19 is advanced enough to warrant hospitalization. By the time a patient is sick enough to need inpatient treatment, they may already be experiencing the massive inflammatory response that makes advanced COVID-19 so dangerous. At that point, the antibodies would have little effect.
When a high-risk individual contracts COVID-19, the process to receive antibodies at our hospital begins with a one-on-one consultation with one of our providers, followed by appointment scheduling for those who qualify for the treatment.
When the patient arrives for antibody treatment, a mask is required. We meet patients at the door to the hospital and escort them directly to our infusion center.
Antibody infusion takes about an hour. We then observe the patient for another hour or so, to avoid the rare allergic reaction. Down the road, we hope to be able to shorten infusion time to as little as 15 minutes.
After infusion, the patient goes home to quarantine and must continue to follow the standard isolation precautions established for people who have tested positive for COVID-19. He or she is also scheduled for a telehealth follow-up with their primary care physician or one of our providers.
Once recovered, should a patient who received monoclonal antibody treatment get the COVID-19 vaccine? Because active antibodies would likely interfere with the vaccine’s effectiveness, we advise waiting at least 90 days before getting a vaccine. Giving the antibodies time to clear the system leaves the immune system primed to respond to the vaccine.
The Future of Treatment
At MedStar Washington Hospital Center, we have already delivered antibody treatment to hundreds of patients, preventing a number of hospitalizations and potentially saving lives. New treatment agents are on the horizon, and development will continue on others.
We’re confident that future treatments will be even more effective. For example, EUA was granted in February for a new combination of bamlanivimab and etesevimab. This combination targets two of the coronavirus spike proteins, compared to just one for previous treatment agents.
We’re already very encouraged by what we have seen with the current monoclonal antibody treatments. And we’re excited about the opportunity to keep introducing new and better treatments here in the future.
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