Positive early data from large Phase 3 COVID-19 antibody trial
Pharmaceutical company Eli Lilly has announced its experimental antibody treatment can reduce a person’s risk of contracting COVID-19 by up to 80 percent. These preliminary results, from an ongoing Phase 3 trial, suggest the treatment may be an effective way to rapidly tamp down coronavirus outbreaks in unvaccinated communities.
Unlike a vaccine, which teaches the body to produce its own antibodies against a virus and can take weeks to generate effective immunity, monoclonal antibody treatment involves directly infusing large volumes of lab-produced antibodies into a patient.
In October last year Donald Trump touted the efficacy of antibody treatments after he received an experimental COVID-19 antibody cocktail produced by pharmaceutical company Regeneron. The next month Eli Lilly’s antibody treatment, called bamlanivimab, was granted Emergency Use Authorization by the US Food and Drug Administration (FDA).
With clinical trials still ongoing researchers are working to understand the optimal way to administer these kinds of antibody treatments. When the FDA granted bamlanivimab emergency authorization last year it was clear to note the approval was very limited to patients at the earliest stage of COVID-19. In fact, trials have indicated these treatments can worsen a patient’s condition if administered in later stages of the disease.
So all signs have suggested bamlanivimab, and other monoclonal antibody treatments, are probably most effective when administered to newly infected patients, or as a preventative agent for those in high-risk environments. Eli Lilly’s new announcement is reporting some data from a unique Phase 3 trial investigating whether bamlanivimab prevents COVID-19 infections in nursing homes or assisted care facilities.
The ongoing trial, which began in August, identified nursing home COVID-19 outbreaks and rapidly dispatched teams to administer infusions of either bamlanivimab or placebo to staff and patients within seven days of the first case being reported. The results recently announced by Eli Lilly claim those residents receiving bamlanivimab were up to 80 percent less likely to contract COVID-19 compared to residents in the same facility given a placebo.
"The results of this innovative study further support the belief that bamlanivimab – and potentially other monoclonal antibodies – can reduce symptoms and may even prevent COVID-19," says Myron Cohen, co-principal investigator on the trial. "The antiviral activity seen with bamlanivimab treatment emphasizes the importance of early intervention to help counter the devastating impact the virus has had in this vulnerable population and other high-risk patients."
As the trial is still ongoing these results have yet to be published in a peer-reviewed journal, so it is difficult to evaluate exactly how best these monoclonal antibody treatments can be used. Experts not affiliated with the research are cautiously optimistic, suggesting these findings are good news.
“The investigation reports a very significant impact – reducing both symptomatic disease and deaths,” says Daniel Altman, from Imperial College London. “This is a big result when one considers the massively disproportionate disease burden and fatalities around the world in care-homes. Earlier results in severe patients in a hospital setting had been disappointing, perhaps reflecting the point that at that later stage of disease, other disease processes are implicated, rather than just virus entry.”
Considering vaccines are currently being rolled out it is fair to ask what particular role these kinds of antibody treatments will have in the greater fight against COVID-19. Daniel Skovronsky, chief scientific officer at Eli Lilly, suggests bamlanivimab offers doctors a valuable tool that could help quash acute outbreaks, particularly in unvaccinated or high-risk populations.
“Of course, I think the vaccines are more effective than prophylaxis and likely longer lasting,” says Skovronsky. “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.”
Source: Eli Lilly