In animal experiments with the drug plitidepsin, a drug used in tumors, the result was promising in antiviral efficacy and toxicity, according to the company that produces it.

The authors claim that plitidepsin is the compound that has been shown to be the most effective and argue that it should be tested in extended clinical trials.

In two different animal experiments in which there was infection with SARS-CoV-2, a 99 percent reduction in viral loads in the lungs treated with plitidepsin was achieved.

In the article published in Science, researchers note that although toxicity is a concern in any antiviral, the safety profile of plitidepsin in humans is proven.

The drug acts by blocking a human protein (eEF1A) that is present in cells and is used by the new coronavirus to reproduce and infect other cells.

"We believe that our data and initial positive results from PharmaMar's clinical trial suggest that plitidepsin should be seriously considered to extend Covid-19 treatment clinical trials," the researchers consider.