Experts think monoclonal antibodies, like the cocktail taken by Mr. Trump, could fare better than hydroxychloroquine and convalescent plasma.
The treatment is “super promising, and all of us are excited from a theoretical perspective,” Dr. Ranney said. “But it’s just too early,” she added, to tell if theory will translate into practice.
Monoclonal antibodies are synthetic, mass-produced mimics of the molecules the human body produces in response to an infection. Some antibodies are powerful enough to block the coronavirus from infiltrating cells. Administered to people battling the coronavirus, the monoclonal antibodies could help naturally produced immune molecules fend off the virus.
Just days before Mr. Trump tested positive for the coronavirus and was admitted to the hospital, Regeneron announced a batch of preliminary results, collected from ongoing trials, via news release. They suggested Regeneron’s monoclonal antibody cocktail could tamp down the amount of virus found in the nasal cavity, and hasten recovery in people who had contracted the virus but hadn’t been hospitalized.
On Wednesday evening, Regeneron announced it was seeking an emergency approval from the F.D.A. for its antibody cocktail.
The data so far for monoclonal antibodies looks “very promising,” said Dr. Phyllis Tien, an infectious disease physician at the University of California, San Francisco. But it’s crucial, she added, to let the trials run to completion to fully assess safety and efficacy. Unanticipated side effects could crop up, or the treatment might not perform as well in certain people as it does in others.
Mr. Trump’s allusions to making monoclonal antibodies “free” for widespread use are also probably off base. Monoclonal antibodies are expensive and difficult to produce in large quantities. Regeneron estimated that it would initially have enough doses for only 50,000 people, though the company plans to scale up production in coming months.
What’s cheaper, Dr. Ranney said, are the many preventive strategies available to keep the virus from infecting people in the first place, such as masks and physical distancing: “How about we focus on that?”