Inspired by a unique kind of infection-fighting antibody found in llamas, alpacas, and other camelids, a research team at the University of California, San Francisco, has synthesized a molecule that they say is among the most potent anti-coronavirus compounds tested in a lab to date.
Called nanobodies because they are about a quarter of the size of antibodies found in people and most other animals, these molecules can nestle into the nooks and crannies of proteins to block viruses from attaching to and infecting cells.
The lab-made one created by the UCSF team is so stable it can be converted into a dry powder and aerosolized, meaning it would be much easier to administer than Covid-19 treatments being developed using human monoclonal antibodies. While the work is still very preliminary, the goal is to deliver the synthetic nanobody via simple inhaled sprays to the nose or lungs, allowing it to potentially be self-administered and used prophylactically against Covid-19 — if it’s shown safe and effective in both animal tests and clinical trials.
After four months of working nearly around the clock, the team posted the results Monday to the bioRxiv preprint server. The paper has not yet been peer-reviewed, but the researchers said they are already in talks to find a partner that can quickly test, manufacture, and distribute the new compound in hopes it can prevent new infections and mitigate disease in those who are already infected. “Every day, 5,000 people die of this disease. We’d like as soon and as fast as possible to find a partner to make this,” said Peter Walter, a veteran biochemist who permanently resides on many short lists of those expected to win a Nobel Prize and who co-led the project with structural biologist Aashish Manglik.
Well-aware of the furor over early announcements for coronavirus therapies, the duo do not want to oversell their findings and acknowledge the nanobody, called Aeronab 6, needs to be tested in clinical trials. But they are enthusiastic because of both how stable the compound is and how well it has responded in lab tests where it inhibits the infection of cells by binding ferociously to the infamous spike proteins that allow coronavirus particles to enter and infect cells. “It’s almost like a mousetrap that never lets go,” said Walter.
While the lab results look promising, experts in the field advise caution because important work has not been done to test the compound in animals. “The critical thing is animal data. We’ve found things that are very potent in vitro that do nothing in vivo,” said Dimiter Stanchev Dimitrov, a professor of medicine who directs the Center for Antibody Therapeutics at the University of Pittsburgh and has created antibody-based therapeutics for numerous viruses including SARS and MERS, two other coronaviruses. He said it can take months to collect the needed data in animals. “Once these are tested in animal models, then I…