Eli Lilly said Thursday that its monoclonal antibody prevented Covid-19 infections in nursing home residents and staff in a clinical trial, the first time such a treatment has been shown to prevent infection.
Lilly released the results in a press release, although it said that it would publish the data in a research paper as quickly as possible.
In November, the antibody, bamlanivimab, was authorized for emergency use by the Food and Drug Administration in treating patients with Covid who are at risk of more severe disease. An antibody cocktail made by the biotechnology firm Regeneron has also been authorized.
But Lilly believes its antibody could be an option not just to treat Covid-19 but to help prevent it in limited circumstances.
“Of course, I think the vaccines are more effective than prophylaxis and likely longer lasting,” Daniel Skovronsky, Eli Lilly’s chief scientific officer, said in an interview. “So this should not be seen in any way as competition to vaccines. It should be for when it’s too late, when there’s an outbreak and people are getting exposed and there’s not going to be time for a vaccine to work.”
The study, begun Aug. 3, was conducted with the National Institute of Allergy and Infectious Diseases. Lilly used an unusual strategy: a fleet of refitted recreational vehicles that could prepare study drug, do lab work, and pull trailers that could be used as on-site infusion clinics. That meant that when a nursing home or long-term care facility had an outbreak, an RV could be dispatched. Lilly developed the antibody in collaboration with Abcellera, a Vancouver biotech.
Lilly enrolled 1,097 participants in the study. Of these, 132 tested positive for the SARS-CoV-2 virus, which causes Covid-19, at the beginning of the study. Of the remaining participants, 300 were residents of long-term care facilities and the rest were facility staff, including health care workers.
Among these, 965, symptomatic Covid-19 infections were reduced by 57%. Among the 299 patients who were nursing home residents, the results were stronger still, reducing symptomatic Covid-19 cases by 80%. In both cases the result was statistically significant.
There were four deaths among the 965 patients, all of them in the placebo group. When the 132 who tested positive at the study’s beginning were included, there were another four deaths — again, only among patients who received placebo. All deaths were in residents, not staff.
Among the 299 nursing home residents, there were four deaths attributed to Covid-19, all in the placebo arm. Among the 41 nursing home residents who tested positive at the study’s beginning, there were four deaths, again in the bamlanivimab arm.
In order to get a long duration of effect from the antibodies, Lilly used a dose of 4.2 grams, about six-fold higher than the dose authorized for use in patients with Covid-19. Bamlanivimab is given intravenously.
Covid-19 vaccines have already been made available to patients in nursing homes, Skovronsky acknowledged. But he said the antibodies could still be useful if there are outbreaks in places the vaccines have not reached. Eli Lilly will discuss with the FDA whether a new emergency authorization is warranted. Regeneron is conducting its own Covid prevention study in households where one member was infected.
Skovronsky said that he also hoped that the results would encourage people who develop Covid to receive antibody treatment. Use of the monoclonal antibodies has been more sporadic than expected, in part because of distribution problems and in part because doctors and patients don’t know to ask for them. The government has purchased large stocks of antibodies from both Lilly and Regeneron; whether the drugs are used more after governments purchase them makes no difference to the companies.