Scientists say they found a promising new treatment for COVID-19. The experimental oral antiviral drug seems to be stopping the virus from replicating itself. The National Institutes of Health (NIH) released the results of the study Thursday.

The drug, called TEMPOL, can reduce Covid-19 infections by impairing an enzyme the virus needs to make copies of itself once it is inside human cells, which could potentially limit the severity of the disease, researchers at the NIH said. The drug was tested in an experiment of cell cultures with live viruses.

“We urgently need additional effective, accessible treatments for COVID-19,” Dr. Diana W. Bianchi, director of the NIH’s National Institute of Child Health and Human Development, wrote in a statement. “An oral drug that prevents SARS-CoV-2 from replicating would be an important tool for reducing the severity of the disease.”

“Given TEMPOL’s safety profile and the dosage considered therapeutic in our study, we are hopeful,” said Dr. Rouault. “However, clinical studies are needed to determine if the drug is effective in patients, particularly early in the disease course when the virus begins to replicate.”

The study team plans on conducting additional studies and will seek opportunities to evaluate TEMPOL in a clinical study of COVID-19.