The ivermectin arm of the U.K.'s PRINCIPLE trial is "currently paused due to temporary supply issues," according to the trial's .
The website does not offer any details on what caused the ivermectin supply difficulties in PRINCIPLE, which is investigating possible treatments for COVID-19 and being led by the University of Oxford in England.
A full response from the trial's press team was promised, but had not reached 鶹ý by press time.
Ivermectin manufacturer Merck did not directly comment on the supply issues affecting PRINCIPLE. However, as part of a longer statement on the drug provided to 鶹ý via email, the company said that it has "concluded that the probability of ivermectin providing a potentially safe and efficacious treatment option for SARS-CoV-2 infection is low and have prioritized internal efforts towards the development of alternate candidates that provide a higher probability of success for the treatment of COVID-19."
"If clinical data emerge providing definitive evidence for a positive benefit-risk assessment of the use of ivermectin in COVID-19, we stand ready to provide our expertise and resources as needed," Merck added.
Another drug under investigation in PRINCIPLE is the . As COVID-19 cases rise in the U.K., the need for medications to prevent serious illness and hospitalizations may be greater than ever.
As of Tuesday, the website listed 8,287 participants recruited and still featured an active link to join PRINCIPLE. An individual who is currently experiencing COVID-19 symptoms and has a positive test may be eligible to participate in the trial, which is entirely remote.
PRINCIPLE also is recruiting participants through general practitioners across the U.K. The trial is open to individuals regardless of vaccination status.
The trial is designed to "test a range of treatments in the community," according to the PRINCIPLE website, "with treatment arms that can be stopped, replaced or added."
The use of ivermectin for patients with COVID-19 continues to spark controversy, especially in the U.S. Some doctors have challenged their hospitals over their ability to try ivermectin in patients with COVID, while lawsuits from family members of COVID patients, who seek ivermectin for their loved ones, have been filed in several states including New York, Illinois, and Ohio.