Regeneron: How monoclonal antibody therapy has been shown to prevent COVID-19 works in phase III trials

Therapy Regeneron this is is part of a class of treatments called monoclonal antibodies, who are made for act like immune cells and fight infections. The drug, called REGN-COV2, is designed to prevent infected people from developing serious illness. Instead of waiting for the body to develop its own protective immune response, it mimics the body’s natural defenses. It was administered to the former US President Donald trump shortly thereafter, he was diagnosed with COVID-19 and was given emergency clearance in the United States by the FDA at the end of last November.

This Monday, the American laboratory Regeneron and its Swiss partner rock revealed promising new clinical trial results of a experimental cocktail designed to reduce the risk of COVID-19 infection. Phase III trials, corresponding to the most advanced phase of clinical studies, carried out to assess the combination of casirivimab and of imdevimab, they achieved their main goals, the US lab said in a statement.

“It is a mixture of pairs of human monoclonal antibodies. In the United States, the treatment works very well. However, one of the main problems of this therapy this is its high cost “, held in dialogue with Infobae Guillermo Docena, biochemist and immunologist, professor of immunology at the National University of La Plata and principal investigator of CONICET.

The study recruited 1,500 healthy volunteers, each sharing a home with someone who tested positive for SARS-CoV-2, and randomly assigned them to receive a single dose of your antibody treatment, administered subcutaneously in four injections, or a placebo. After 29 days, 11 patients in the treatment group developed COVID-19 compared to 59 on placebo. And for subjects who contracted COVID-19 despite treatment, their symptoms disappeared after a week, compared to three weeks for those who received a placebo. In 204 patients who had already tested positive for the SARS-CoV-2 virus at the start of the study, the injection reduced their chances of progressing to symptomatic COVID-19 by 31%.

Antibodies against RAIN-COV2 they attack the surface of the SARS-CoV-2 protein peak and neutralize its ability to infect healthy cells. According to Regeneron, Blocking this interaction between the virus and the cells of the infected person stops the infectious process and helps reduce high levels of viral load. generally associated with greater severity of illness caused by coronavirus.

The results reflect findings similar to those observed in a study conducted by Eli lilly about his monoclonal antibody in retirement homes. One key difference: While in previous studies conducted by both Lilly and Regeneron, antibodies had to be administered intravenously, in this Regeneron used a formulation that could be given by injection under the skin. Lilly is also exploring a subcutaneous injection of her antibodies.

It is “really, very important,” he said. Myron Cohen, Director of University of North Carolina Institute for Global Health and Infectious Diseases and one of the study’s principal investigators. For him, having to start an IV is “unequivocal” one of the barriers to using antibodies for treatment or prevention. The other barrier? Consciousness.

“For these antibodies to be used for treatment and prevention and for treatment as prevention, we need patients or their families to know the opportunity ”, warned Cohen. “We need healthcare professionals to know about these drugs and feel comfortable giving them. From the company, they announced that plan to apply to the US Drug Agency (FDA for its acronym in English) allow your medicine to be given by injection, as administered in the study results, which this would allow it to be managed more quickly and easily.

George Yancopoulos and Leonard S. Schleifer, founders of Regeneron Pharmaceuticals, they referred in the STAT 2020 Summit, where the highest referents of the American health system talk about the coronavirus crisis, among other things, the need to target a specific distribution. As the researchers warn, the cocktail of monoclonal antibodies has been shown to be “Particularly effective” in patients with the early stages of COVID-19, they have one high viral load, show mild to moderate symptoms and which the body has not yet produced antibodies, something that is “Absolutely essential”.

Why do we need antibodies when there are already vaccines? Dan Barouch, Director of Beth Israel Deaconess Medical Center Virology and Vaccine Research Center and a key figure in the development of the J&J vaccine and another researcher in the study of Regeneron he said that the approaches are “complementary”.

“Currently, there are still a considerable number of people who are not fully vaccinated ”, Explain Barouch. And he added: “It’s more, some people, including those with weakened immune systems, may not make enough antibodies by themselves, and they could benefit from the antibodies injected into their body. In certain circumstances, such as an outbreak in a nursing home, monoclonal antibodies, which start working immediately, might be the best approach. “

For its part, Yancopoulos explained during the meeting he attended Infobae, why antibody treatment alone will not be enough to beat the coronavirus, but on the contrary a vaccine will also be necessary. “Of course, the hope is that a vaccine is to drastically limit the need for treatment by reducing the numbers to the catastrophic levels we are at now. But we all understand that this is going to take time, that it will be an evolving process, and that we are in the early stages. “

“Antibodies are given to people who are already sick to treat them. The purpose of a The vaccine aims to protect people against infection and it can be given to millions of people around the world, which is not possible with a cocktail of antibodies ”, He said. Therefore, “in a sense, a vaccine is more useful because it will help build a strong wall of immunity against the virus ”. However, he clarified: “There are always vulnerable or elderly people, and in these cases the efficacy of a vaccine is lower, so the efficacy of antibody therapy in these cases could be greater.”

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