Makers of monoclonal antibody treatments say they have shown the therapies can help prevent severe coronavirus disease in people who are already infected. Now they’re planning to ask the US Food and Drug Administration for authorization to use them as a kind of “passive vaccine” to protect people at high risk of infection.
The treatments made by Regeneron and Eli Lilly and Co. are only authorized for use with non-hospitalized patients at high risk of severe disease. If they get the FDA’s OK, it’s still an open question as to how many people will use them.
The United States has been slow to roll out Covid-19 vaccines, and for different reasons, it’s been even slower to adopt monoclonal antibodies. The companies are gambling that maybe Americans will be quicker to embrace these lab-engineered immune system proteins as prevention.
Monoclonal treatment 101
However, the treatments are not as simple as swallowing a pill. A nurse wearing full protective gear needs to administer the treatment for about an hour and then monitor the patient for another.
Monoclonal treatments have a lot of advantages. They work right away, unlike a vaccine that takes a few weeks to kick in.
Plus, they’ll cost the patients nothing under an agreement the companies reached with the government, although there may be an administration fee.
Both companies released additional details about the results of prevention trials Tuesday, although they have yet to publish the results.
Antibody treatments may protect nursing homes
On a shareholder call Tuesday, Lilly discussed what it called “a remarkable” prevention trial that it did with nursing home patients and staff.
Lilly set up on-site infusion centers at nursing homes that had reported a recent Covid-19 case. The company infused 965 people who tested negative for the coronavirus and 132 who tested positive.
Half the volunteers got the treatment, known as LY-CoV555or bamlanivimab, while the other group got a placebo, which does nothing.
After eight weeks, trial results showed residents and staff who got the treatment had an 80% lower risk of testing positive for Covid-19 than the people in the same facility who got a placebo.
During the trial, 16 residents died, some of them from Covid-19. No staff did. Eleven of those who died were among the group that got the placebo, compared to five who had received the antibody therapy.
“Bamlanivimab can play a critical role in turning the tide of this pandemic,” said Lilly’s chief science officer Dr. Daniel Skovronsky. He said he believes it can help the country’s most vulnerable demographic. Nursing homes have had high rates of infection and accounted for 40% of US Covid-related deaths, a January study found.
Antibody treatments may protect against infections in the home
Regeneron has been testing its antibody treatment as a way to protect people vulnerable to infection after someone in their own home has tested positive.
Among 400 volunteers, half got the therapy and half got a placebo. The number of infections was lower among those who got the treatment, the company said Tuesday.
Among the volunteers who got the therapy, those who did get sick had symptoms that lasted no more than one week, while 40% of people in the placebo group who got infected were sick for three to four weeks.
None of those who were infected who received the therapy had high viral loads, while 62% of those in the placebo group who were infected had high viral loads.
One person given placebo died. There were no deaths or hospitalizations in the group that got the treatment.
Eli Lilly and Regeneron argue that their treatments can play an important role in the pandemic, even as more people get vaccinated.
Where antibodies fit in a world with vaccines
“These data using REGEN-COV as a passive vaccine suggest that it may both reduce transmission of the virus as well as reduce viral and disease burden in those who still get infected,” Dr. George Yancopoulos, president and chief scientific officer at Regeneron, said in a news release.
“Even with the emerging availability of active vaccines, we continue to see hundreds of thousands of people infected daily, actively spreading the virus to their close contacts. The REGEN-COV antibody cocktail may be able to help break this chain by providing immediate passive immunity to those at high risk of infection, in contrast to active vaccines which take weeks to provide protection,” Yancopoulos said.
Lilly’s Skovronsky said there is “variable uptake of vaccination,” in nursing homes. In some cases less than 50% want to be vaccinated.
“There are deaths every day in these facilities and that motivates us to be aggressive about prophylaxis, where we think we can have a quick impact during this sort of uncertain mixed vaccination period,” Skovronsky said.
Skovronsky also thinks there may come a day when the vaccines may not fully protect against the new variants of Covid-19.
“That probably informs our thinking on next generation antibodies and the need to stay ahead of this,” Skovronsky said.
Lilly is testing bamlanivimab against new variants of the virus. Regeneron’s tests on two different variants of the coronavirus show that one of the two monoclonal antibodies in its cocktail therapy can neutralize both, despite the mutations.
If approved how do people get these treatments
So far, the US has been slow to adopt antibody treatments. Last week the Health and Human Services Department told CNN that of the antibody treatments sent out, on average only 39% have actually been used.
It’s unclear if more people will use a treatment that can protect them from getting sick. It’s also unclear if the FDA will authorize the monoclonals for this kind of use. If they get emergency use authorization, the companies said they have laid the groundwork and have already taken steps to educate people about these treatments and encourage more people to use them.
Eli Lilly said it has set up a 24 hour support line and there now are a number of websites, including Covid.infusioncenter.org, that can help people find infusion centers close by.
Some states have also tried to be more proactive. Contact tracers have been encouraged to mention them when letting someone know they’ve been recently exposed to Covid-19.
Some hospitals have also tried to be proactive, using electronic records to quickly get in touch and offer treatments as soon as they get a positive result. If the FDA allows these treatments to be used preventively, the systems could always adjust to contact a person as soon as they have been tested, without regard to the result.
Regeneron said if its treatment is authorized for prevention, a doctor could always prescribe it for the person being treating and for their household.
Get CNN Health's weekly newsletter
Sign up here to get The Results Are In with Dr. Sanjay Gupta every Tuesday from the CNN Health team.
Eli Lilly said if people really want these treatments, they may have to ask for them directly.
“I think patients and providers, in some cases, have to be persistent to navigate our health care system as is, unfortunately, often the case with different diseases, to get optimal therapy,” Skovronsky said. “But for patients who want it and qualify and providers who think it’s right for their patients, it’s widely available.”