After Covid-19 vaccine, next big step may be a class of biotech antibodies

As the world awaits a Covid-19 vaccine, the next big advance in battling the pandemic could come from a class of biotech therapies widely used against cancer and other disorders - antibodies designed specifically to attack this new virus.

Development of monoclonal antibodies to target the virus has been endorsed by leading scientists. Anthony Fauci, the top U.S. infectious diseases expert, called them "almost a sure bet" against Covid-19.

When a virus gets past the body's initial defenses, a more specific response kicks in, triggering production of cells that target the invader. These include antibodies that recognise and lock onto a virus, preventing the infection from spreading.

Monoclonal antibodies - grown in bioreactor vats - are copies of these naturally-occurring proteins.

Scientists are still working out the exact role of neutralising antibodies in recovery from Covid-19, but drugmakers are confident that the right antibodies or a combination can alter the course of the disease that has claimed more than 675,000 lives globally.

"Antibodies can block infectivity. That is a fact," Regeneron Pharmaceuticals executive Christos Kyratsous told Reuters.

Regeneron is testing a two-antibody cocktail, which it believes limits the ability of the virus' to escape better than one, with data on its efficacy expected by late summer or early fall. "Protection will wane over time. Dosing is something we don't know yet," said Kyratsous.

The U.S. government in June awarded Regeneron a $450 million supply contract. The company said it can immediately begin production at its U.S. plant if regulators approve the treatment.

Eli Lilly and Co, Amgen, and GlaxoSmithKline were cleared by the U.S. government to pool manufacturing resources in order to scale up supplies if any of these drugs prove successful.

Even with that unusual cooperation among rivals, manufacturing these medicines is complex and capacity is limited. There is also a debate over whether a single antibody will be powerful enough to stop Covid-19.

AstraZeneca said it plans to start human trials of its dual-antibody combination within weeks.

Lilly, which began human testing in June of two antibody candidates in separate trials, is focusing on a one-drug approach.

"If you need a higher dosage or more antibodies, fewer people can be treated," Lilly Chief Scientific Officer Dan Skovronsky said.