Potential Antibodies Treatments for COVID-19

Daniel Marcus';

By Daniel Marcus

Posted on February 20th, 2021 in Covid-19

In October 2020, as part of his treatment for the novel coronavirus, US President Donald Trump received Regeneron Pharmaceuticals’ experimental antibody cocktail REGN-COV2. Both Regeneron and Eli Lilly filed subsequent requests for Emergency Use Authorization from the US Foods and Drug Administration. 

Buoyed by a positive response, Cedars-Sinai scientists are looking for antibodies to detect and treat COVID-19. Several studies examine what antibodies can do at every stage of dealing with COVID-19, including diagnosis, treatment, predicting the disease course.

In fighting off pathogens, the body is like a fortress under siege. Like any castle, the body protects itself from infectious microbes through several lines of defense.

The first line is the innate immune system. It sets out to discourage any potential intruder. Raising the body’s temperature with a fever and assaulting pathogens with toxic chemicals makes the body as inhospitable for them as possible.

Pathogens that have developed stealth to evade the immune system and counter inflammatory responses dedicated to stopping germs can overwhelm and outmaneuver even these security forces. When that happens and a pathogen has invaded, the body has learned the type of threat it poses, and antibodies and T cells kick in. 

Clinical Trial Shows Monoclonal Antibodies Hold Promise for Fighting the Pandemic

Cedars-Sinai is one of the lead sites taking part in a multi-site, Phase II clinical trial using a monoclonal antibody (LY-CoV555) derived from the blood of one of the first patients to recover from COVID-19, according to a new study published in The New England Journal of Medicine.

The uniquely synthesized antibodies aim to block the virus from entering cells and prevent it from replicating. The COVID-19 patients who were administered the single-injection treatment had fewer symptoms. It was less likely to require emergency medical care or hospitalization than those who did not receive the antibody.

In the randomized, double-blind study, investigators gave patients intravenous doses of either 700, 2,800, or 7,000 mg of LY-CoV555 or a placebo. Around 300 patients received the treatment, and 150 patients received the placebo.

Investigators tested patients' viral load using a nasopharyngeal swab before administering the antibody and at several points after administering it. Patients in the trial also received a questionnaire about their subsequent symptoms and treatment.

The clinical trial tested three different doses of the novel antibody. While the trial is ongoing, results from the interim analysis showed:

  • a reduced viral load in outpatients with mild-to-moderate cases at 2,800 mg dosage level
  • reduced rates of hospitalization and emergency care for patients at all dosage levels

By day 11, the 2,800 mg dosage substantially diminished viral load for most patients, including those in the placebo arm. According to the investigators, they will need further studies to validate these results.

The most significant finding was the fact that LY-CoV555 has the potential to reduce COVID-19 severity for many patients, allowing more people to recover at home.

The principal co-author in the study at Cedars-Sinai is Peter Chen, MD, director of Pulmonary and Critical Care Medicine. The other co-authors of the new study were researchers from Eli Lilly and Company. The research involved investigators from 11 institutions and companies. Eli Lilly and Company developed the experimental molecule and funded this trial.

Antibody Tests for COVID-19

In another project, Anders Berg, MD, Ph.D., associate director of Clinical Chemistry and Core Laboratories, investigates the effectiveness of blood tests that measure antibody levels in detecting COVID-19. 

The probability of a false negative from the swab test is high because the virus lives first in the nasal cavity but later may move to other parts of the body that a swab cannot reach. This issue affects especially those who were symptomatic at home or in a nursing facility before being admitted to the hospital. 

Berg and his colleagues are also investigating if antibodies testing might:

  • prove useful as biomarkers to pursue a particular treatment course
  • identify patients who would most benefit from antiviral medications or antibody therapies

The team is working to pinpoint whether the level of antibodies in the bloodstream could help identify patients who are likely to require ventilator support as they're not mounting an adequate immune response to the virus.