Pharmaceutical company Eli Lilly is the latest to temporarily halt one of its covid-19 clinical trials. The Phase III trial, involving an experimental antibody treatment for patients with the viral illness and sponsored by the federal government, was paused due to a “potential safety concern,” according to government emails obtained by the New York Times Tuesday afternoon.
According to the NYT, government officials sent emails Tuesday announcing the pause to scientists involved in the trial. The emails reportedly told researchers to cease the recruitment of new volunteers out of an “abundance of caution.” Eli Lilly separately confirmed the pause in a statement, the NYT reported.
The randomized, double-blinded and placebo-controlled clinical trial, known as ACTIV-3, is set to include 10,000 volunteers hospitalized with covid-19. Those in the treatment group would get an IV infusion of the experimental, lab-made antibody cocktail, called LY-CoV555, alongside standard care (this standard care would include the antiviral drug remdesivir, which has shown promise in shortening the length of illness). It’s hoped that these monoclonal antibodies can safely bolster the body’s natural immune response to infection, preventing or lessening severe symptoms.
The decision to pause the trial comes less than a month after the company had reported promising but preliminary data from earlier, smaller trials of the antibody treatment. This data found that people with mild-to-moderate covid-19 given the antibody were less likely to be hospitalized or to visit the emergency room than those who got the placebo. It also appeared to find that the treatment wasn’t linked to any serious adverse events.
Currently, it’s unknown what safety concerns exactly led to this trial halt, nor how many volunteers may have been affected by it. Neither Eli Lilly nor the National Institutes of Health has responded to a request for comment from Gizmodo.
Eli Lilly’s trial pause is the second involving covid-19 to occur in as many days. Just yesterday, Johnson & Johnson halted its trial of an experimental vaccine for the novel coronavirus, after an “unexplained illness” in one of its volunteers was discovered. Safety pauses are not out of the ordinary during drug and vaccine studies, and they do not necessarily lead to the failure of a clinical trial. Without more details, it’s unclear just how worried we should be about the future of these treatments.