A closer look at the race to develop antibody drugs for COVID-19.
A vaccine is likely what will stop the new coronavirus, so it's no surprise that the dozens of programs speeding through testing are getting so much attention. Even at the unprecedented pace vaccines are moving, the first might not be available until next year. And it'll likely take much longer than that for enough people to be vaccinated that the U.S. achieves 'herd immunity,' and can more definitively curb the spread of SARS-CoV-2.
That's why many experts believe the efforts of a group of companies developing antibody drugs are so vital. Regeneron, Eli Lilly, Amgen and Vir Biotechnology are leading an increasingly competitive race to develop therapies that could give people short-term protection from the coronavirus, or help treat those who are exposed or infected. And they could be more potent than the current standard of care, Gilead's antiviral drug remdesivir, which seems to help hasten recovery from COVID-19 but only modestly so.
"These medicines may be the best chance for a meaningful near-term success," former FDA commissioner Scott Gottlieb recently wrote in an op-ed in the Wall Street Journal.
Still, even if successful — which is no guarantee — these injectable biologic drugs won't solve the pandemic. Their effects are temporary, for instance, and manufacturing will also be a challenge.
But many believe there is a good chance that they could get through clinical testing and be available for use before vaccines arrive. In combination with mass testing and tracing measures, they could, then, be a critical tool in helping keep the disease in check.
"Can you turn this into something where we can take the distancing requirements down in a significant way?" said Ronny Gal, a biotech analyst at Bernstein, in an interview.
The first clinical tests of COVID-19 antibodies should start next month. With those trials approaching, BioPharma Dive spoke with the developers of these drugs and some outside observers about what lies ahead.
What are antibody therapies for coronavirus, and how do they work?
When fighting off foreign invaders, our bodies make antibodies specifically produced for the task. The reason vaccines provide such long-lasting protection is they train the immune system to recognize a pathogen, so immune cells remember and are ready to attack the virus when it appears.
Monoclonal antibodies for coronavirus would take the place of the ones our bodies might produce to fight the disease. Specifically engineered to act like coronavirus-fighting immune cells, the manufactured antibodies would be infused into the body to either tamp down an existing infection, or to protect someone who has been exposed to the virus.
This approach has proven effective against infectious diseases before. A major study in the Democratic Republic of the Congo, for instance, showed a cocktail of antibodies developed by Regeneron reduced the risk of death from Ebola compared to two other treatments. That success has fueled hopes of a repeat, both for Regeneron and for other companies, too.
"Antibodies are the treatments that turned out to be most useful for Ebola. That may or may not be the case with coronavirus," said Diane Griffin, a professor of infectious diseases and of neurology at the Johns Hopkins University School of Medicine, in an interview.
"But it at least brings to the fore the possibility that antibodies could be an important component for treatment."
Effectively, these drugs are synthetic versions of the convalescent plasma treatments that rely on antibodies from people who have recovered from infection. But the engineered versions are easier to scale because they're manufactured in vats, rather than from plasma donors.
The biggest problem with antibody treatments, however, is their staying power. Their effects only last as long as the antibodies are alive — likely a month or more. As Gal puts it, "the weakness is that they're not a solution."
Why care about antibodies if vaccines are the real solution?
First, it's risky to count on vaccines being developed at an historic pace — testing normally takes many years — and be an immediate panacea. There are many other uncertainties ahead, too. No vaccine has ever been successfully developed for any type of coronavirus, and the most advanced prospects rely on new, unproven technologies that have never been made at the kind of global scale needed to fight a pandemic.
What's more, some vaccines are only effective for a portion of people. Among the hardest to help are elderly people with weaker immune systems — the kind that are most prone to serious complications from coronavirus disease. Vaccine's effects also take time; they don't kick in immediately.
"We don't know if the vaccines will work, when they will work, or how well they will work," said Vir CEO George Scangos in an interview. "I hope it will be the case, but I don't believe it will be the case that vaccines provide universal protection for everyone."
Vaccines aside, the cupboard of drugs that doctors can use to treat infected patients right now is nearly bare. The only treatments granted emergency use by the FDA thus far are the antiviral remdesivir and the generic malaria pill hydroxychloroquine. But remdesivir must be infused over either 5 or 10 days and has only shown it may help shorten hospital stays for people with severe disease. It's unclear what, if any, benefit hydroxychloroquine has.
Social distancing has, thus far, helped to keep case numbers from rising exponentially and reduce strain on the healthcare system. But some states are already reducing such measures or soon will, and the economic pressure to open has grown by the day. That will likely lead to a spike in new cases or, perhaps, a second wave in the fall, experts predict. There is a huge need for a temporary solution that can help people until a vaccine arrives.
"We need something to bridge that gap," said Andrew Adams, Eli Lilly's chief scientific officer of RNA therapeutics in an interview. Adams also works on antibodies.
Author: Ben Fidler
Published: May 12, 2020 https://www.biopharmadive.com/news/coronavirus-antibody-drug-trials/577778/