COVID-19: The National Health Surveillance Agency (Anvisa) has cleared the start of Phase 3 clinical trials with the monoclonal antibody leronlimab against COVID-19. The authorization was announced this Monday (22) by Biomm, the company responsible for marketing the substance in Brazil.
The study will be led by the Academic Research Organization (ARO) of Hospital Israelita Albert Einstein in 35 Brazilian research centers with 612 people hospitalized for infections caused by the coronavirus and requiring oxygen support. The aim is to prevent exacerbation of symptoms in patients and to avoid the use of intubation.
No date has yet been set for the start of clinical trials, which rely on the importation of the drug produced by the company CytoDyn in the United States. The medicinal product is considered to be of general importance for the prevention or treatment of: COVID-19 by the Food & Drug Administration (FDA), a US agency similar to Anvisa.
What are Monoclonal Antibodies?
One of the ways the body’s immune system attacks foreign substances, such as viruses, bacteria and cancer, is by making a large number of antibodies that can attach to a foreign substance, known as an antigen. Once turned on, the antibodies can force other parts of the immune system to destroy cells that contain the foreign substance.
With the development of biotechnology, researchers were able to create proteins that specifically target a particular antigen, such as found in cancer cells or in the coronavirus. These lab-made proteins, which mimic the immune system’s ability to fight specific antigens, are called monoclonal antibodies.
How does leronlimab work?
Leronlimab is an investigational drug that has been studied for the treatment of cancer and HIV infections. With the COVID-19 pandemic, the drug was also tested against Sars-CoV-2.
The drug works to prevent an over-reaction of the immune system in infected patients, known as a “cytokine storm,” when the body produces an excessive level of inflammatory cytokines. The storm is considered by scientists to be the likely cause of the worsening of cases of patients with COVID-19, that can lead to death.
Leronlimab targets the immune receptor CCR5, a protein found on the surface of a variety of cells, including white blood cells and cancer cells. In white blood cells, CCR5 acts as a receptor for chemical attractants called chemokines, a family of small cytokines. By blocking the receptor, the drug prevents viruses or cancer cells from damaging healthy cells.
CytoDyn has conducted two separate clinical studies of leronlimab for the treatment of: COVID-19 in the United States. While it usually doesn’t release preliminary data on unapproved substances, the FDA reported in May 2021 that the available data indicate no clinical benefit from using the drug in infections caused by the new coronavirus.
A smaller study tried to understand the effectiveness of the medicine in 86 patients with mild to moderate infections, but no effect of the medicine on the primary endpoint of the study or on any of the secondary endpoints was observed.
A larger study, involving 394 patients with severe symptoms of respiratory disease associated with COVID-19, also showed no effect of the drug on mortality or on reducing the mean hospital stay in the group analyzed.