A vital group of Covid drugs has stopped working

The changing nature of the virus also makes it difficult to conduct human clinical trials and provide patients with new antibodies in time to combat current subspecies.and December meetingpharmaceutical companies have asked regulators in the United States and Europe to consider adopting new criteria for approving new antibody drugs, particularly those intended for immunocompromised people. He suggested that new antibody drugs similar to those approved would not need to undergo large-scale clinical trials to test their efficacy. , a large lab test and a small safety trial may be sufficient.

Researchers are now searching for the holy grail of antibodies. It is a long-lasting and effective antibody against many SARS-CoV-2 variants, including those that may emerge in the future. Carnahan’s team identified what he called a “small panel of antibodies.” This works for all existing his Covid-19 variants, including XBB.1.5, at least in the lab. They are now looking for a partner company that can further develop these antibodies and test them in clinical trials, a group that previously partnered with his company AstraZeneca, which commercialized Evusheld.

Scientists at Regeneron Pharmaceuticals, a New York-based biotech company, One of the monoclonal antibody treatmentsidentified antibodies that bind to the region outside receptor binding domain. “We were able to identify one of his antibodies against a highly conserved site of the virus,” said Christos Kyratsous, who leads infectious disease research at Regeneron. “It has been conserved since the beginning of the pandemic to this day.

And that gives him hope that even if the virus’ receptor-binding domain continues to mutate in the future, the lab-made antibodies developed to recognize this site will continue to work. says that there is often a trade-off between breadth and potency. There may be many antibodies that bind many variants but do not adequately neutralize them. So far this seems to do both. In clinical trials this summer, Regeneron plans to test the antibody as both a prophylaxis and treatment against his Covid-19.

In December, AstraZeneca began testing potential replacements for Evusheld. Studies in immunocompromised patientsLaboratory studies have shown that the new long-acting antibody neutralizes all SARS-CoV-2 variants tested to date. This includes variants with proven resistance to other monoclonal antibodies. Company statement from JanuaryAstraZeneca said it aims to have the new antibody available in the second half of 2023, pending regulatory approval. The company estimates that about 2% of the world’s population could benefit from her monoclonal antibodies for Covid-19 defense.

Adarsh ​​Bhimraj, an infectious disease specialist at Houston Methodist Hospital in Texas, believes current vaccines and antivirals will suffice for the rest of the population. “This is not him in 2020. There are no drugs in 2020 and the pandemic is causing many deaths and hospitalizations,” he says.

He says the hurdles to getting antibodies approved to treat Covid-19 need to be raised now that effective antiviral drugs are available and mortality and hospitalization rates have fallen. He believes pharmaceutical companies should be able to show that new antibodies can alleviate symptoms and shorten the duration of illness, rather than simply keeping people out of the hospital. , should be studied in trials,” he says.

For now, the FDA recommends that clinics and hospitals keep existing monoclonal antibody drugs on hand. “Monoclonal antibodies don’t work at the moment, but there’s always the chance that Covid-19 variants that he’s in the epidemic will change, so monoclonal antibodies might work again in the future,” Wales said. . “We don’t know that yet.”