Monoclonal antibodies infusion is expected to limit the disease in covid-19 patients with mild to moderate symptoms. Although the therapy is not that common yet, several types of research are in process regarding the efficacy of monoclonal antibodies.
A respiratory virus that was detected back in December 2019 terrified the whole world with its havocking effects. To this date, it has infected 180,900,087 people and has taken 3,918,958 lives. From the beginning, scientists around the globe are trying to find out the methods to halt its spread since it has been increasing the burden on healthcare and pushing the healthcare workers up to the verge of exhaustion.
In this regard, researchers have been investing their time, energy, and knowledge to find a treatment of SARS-CoV-2. They have been using biotech to invent new drugs and vaccines. But the rapid variation in the genomic sequence of viral particles makes it difficult for them to combat the disease.
In this uncertainty, monoclonal antibodies infusion seems like a ray of hope to prevent hospitalizations and frequent visits to Emergency Departments.
What Is Monoclonal Antibody?
To understand the application of Monoclonal Antibodies (MAB) in the treatment of SARS-Cov-2, it is important to know what a monoclonal antibody is? How is it produced? And how does it act against the viral particles?
Monoclonal antibodies are laboratory-produced antibodies mimicking the ones produced by the human body in response to the foreign antigen. In general Monoclonal Antibodies are produced by introducing specific viral proteins to immune cells. As a result, those immune cells produce antibodies in a large amount against that viral protein. In COVID-19, the viral protein scientists have been using to produce monoclonal antibodies is the spike protein, which helps the viral particle adhere and enter the human cell. MAB binds to s-protein and prevents them from performing their duty while triggering the immune response to destroy viral particles.
Studies revolving around the efficacy of MAB have been coming since the very start of the pandemic. Now it seems like research has got some more pace with advancing knowledge of the viral genome. Scientists are now estimating that the induction of Monoclonal Antibodies earlier in the disease can prevent people from hospitalizations.
Study On Effectiveness Of COVID-19 MAB
Research supporting the fact, published in Open Forum Infectious Diseases journal on the 4th of June 2021. Via the Tampa General Hospital (TGH) combined efforts and the University of South Florida Health (USF Health). It started on the 18th of November, 2020, and ended on the 5th of January, 2021, under the supervision of Asa Oxner, MD, USF Health Morsani College of Medicine.
Purpose Of This Study
The study was conducted to evaluate the effectiveness, sensitivity, and specificity of COVID-19 Monoclonal Antibodies. Especially the MABs in Bamlanivimab and Casirivimab/Imdevimab. Furthermore, it ruled out the relation of MABs to hospitalization and visits to the Emergency Department.
Details Regarding The Study Design And Participants
The study protocol that USF’s review board approved was a retrospective cohort study. Including the 200 out-patients who were about to take MABs. The age and weight of participants were according to the FDA’s EUA on Monoclonal Antibodies. Coming towards the symptoms, they had mild to moderate symptoms of COVID-19 for the past ten days or less, and they were at high risk for progression in the disease.
However, there was another cohort, the control cohort, which did not take monoclonal antibodies. This cohort also followed the EUA’s criteria and included the same number of participants, i.e., 200.
To analyze the situation, researchers divided the outcomes into two separate groups, the primary one and the secondary. Primary outcomes included hospitalizations and visits to ER within 29 days of monoclonal antibodies infusion or diagnosis. In contrast, secondary outcomes included all-cause mortality and any severe adverse event related to Monoclonal Antibodies infusion.
Cohort, which gets MAB jabs, faced fewer hospitalizations and ER visits than the control group, with an astounding difference in the statistics. For instance, it stated that only 13.5% of individuals needed hospitalization among the participants who received monoclonal antibodies infusion, in contrast to 40.5% of individuals from the control group.
Talking about the individual, MAB, results were almost the same for both bamlanivimab and casirivimab/imdevimab. In the case of the bamlanivimab vs. control group, the ratio was 14.5% vs. 40.5%. Stats were also similar in casirivimab/imdevimab, where the ratio was 10.5% vs. 40.5%.
In secondary outcomes, the all-cause mortality was 0% in the MAB group, whereas it was 3.5% in a controlled group. However, two patients who received Monoclonal antibodies showed adverse reactions. One participant experienced rectal bleeding soon after the administration, and the other one had an allergic reaction, treated with diphenhydramine.
Time To Administer Monoclonal Antibodies Infusion
There was also a significant role of a day of antibody administration. It found out that the people who received their dosages earlier in the disease had lower chances of hospitalizations and ER visits than those who received it late. For example, chances for such events dropped to 7.7% for the people receiving their jab on the 6th day than those who received MAB after the 6th day, i.e., 28.1%.
Hence, Monoclonal antibodies are beneficial for patients with mild to moderate symptoms of COVID via preventing COVID-19 induced infection and mitigating progression to a severe state. Thus, help in lowering down the burden on hospitals and health care workers.
Several other types of research also highlight the efficacy of MABs and their importance in preventing the disease’s prognosis. One of them was published in nature reviews immunology on the 19th of April, 2021. It highlighted the several perks of MABs and their application in the treatment of COVID-19.
Other Facts About MABs
MABs are intended to bind only to one epitope, representing their monovalent affinity. It also helps distinguish them from plasma antibodies that are polyvalent and can bind to several epitopes.
Apart from its use in coronavirus, MAB is applicable in certain other viral diseases such as Human Immunodeficiency Virus (HIV). In addition, it is also beneficial to treat certain types of cancers by destroying their cell walls or hampering the protein synthesis mechanism.
Casirivimab And Imdevimab
The most common or, say, prevailing Monoclonal Antibody-based vaccines are casirivimab and imdevimab, also known as REGN10933 and REGN10987, respectively. American company Regeneron Pharmaceuticals produced them, and now they are available under the title REGN-COV2.
REGN-COV2 is an IgG1 type of Neutralizing Monoclonal Antibody with unmodified Fc regions. It aims to act against the spike proteins of the SARS-Cov-2.
On the 21st of November, 2020, US Food and Drug Administration, FDA authorized casirivimab and imdevimab under Emergency Use Authorization (EUA) to treat mild to moderate cases COVID-19, especially the ones who are at high risk and can need hospitalization. Patients eligible for this were adults and children aged 12 years or more weighing a minimum of 40 kilograms, i.e., around 88 pounds.
However, there are some limitations in the administration of casirivimab and imdevimab. People hospitalized and on oxygen therapy because of COVID-19 are not authorized to use casirivimab/imdevimab. People who are 65 years and above or those dealing with chronic illnesses are at high risk. Including them, the people who have Body Mass Index (BMI) equal to or greater than 35 are also prone to disease progression.
AbCellera Biologics and Eli Lilly developed MAB infusion under the title Bamlanivimab. Similar to casirivimab and imdevimab, FDA also authorized it under EUA back in November 2020. But it has revoked authorization for bamlanivimab because of concerns regarding its in-vitro activity with variants of SARS-CoV-2. This fact also limited the study of USF as the author stated the reason for limitations was a large number of bamlanivimab therapies and its revocation of EUA approval.
Possible Risk Factors Of MAB
People getting Monoclonal Antibodies can encounter potential risk factors. According to the article published by Jama Network on the 5th of February, 2021, some allergic or nonallergic reactions because of monoclonal antibodies infusion can represent as:
- Shortness of breath
- Low blood pressure.
- Pain, bruising, or soreness around the site of administration can be there too.
Every latest research regarding the treatment of COVID-19 helps to keep our hopes alive for a COVID-free world. This research from USF and TGH highlighted an important aspect of monoclonal antibodies in the treatment of coronavirus. Since there is a notable difference among the number of hospitalizations when comparing the efficacy of MAB-based vaccinations with a control group. It can be beneficial to prevent hospitalization and all-cause mortality. Thus, it can ease the burden on the health care system.
Currently, we have one MAB vaccine available that FDA has authorized under EUA, which is casirivimab and imdevimab. This combination regimen seems preferable for COVID-19 patients aged 12 years or more, suffering from mild to moderate symptoms and deemed high-risk.
It is not the end, several studies are in line, and several institutes and their scientists are investing their time and efforts to rule out more about the outcomes of MAB in the treatment of COVID-19.