A Promising Antiviral Is Being Tested for the Coronavirus

As the coronavirus outbreak continues to spread worldwide and more people become critically ill, scientists are racing to find a treatment that will help turn the tide. Dozens of medicines are in clinical trials in China—and now in the U.S.—to treat the disease, officially named COVID-19. Some are antiviral drugs that are already used to narrowly target other viruses. Experts say these medications are unlikely to do much against the novel coronavirus. Other drugs being tested—such as the broad-spectrum antiviral remdesivir, developed by Gilead Sciences—could prove quite effective, some evidence suggests. But only the rigorous, controlled clinical studies now underway will be able to confirm this possibility.

At the time of this writing, the COVID-19 outbreak has sickened more than 82,000 people globally and killed more than 2,800 of them. No vaccine or direct treatment currently exists. The more than 80 clinical trials being conducted in China involve drugs that were developed to treat illnesses such as HIV/AIDS, malaria and Ebola. These candidates include HIV antivirals called protease inhibitors, which work by blocking enzymes the virus needs to replicate, and a malaria drug called chloroquine, which is not an antiviral but has shown some efficacy against COVID-19 in a lab dish. Yet experts say drugs that specifically target other pathogens are unlikely to work well enough.

The mistake generally made these days is to think that [just] any antiviral would be effective against [the coronavirus]. This is, of course, not true,” says Erik De Clercq, an emeritus professor of medicine at KU Leuven in Belgium, who helped discover the HIV antiviral tenofovir. De Clercq believes scientists should focus on developing compounds tailored to the new virus.

Instead of being in a hurry [to test] all known compounds—what they now call ‘repurposing a compound,’—we really need new compounds that are specific for [the coronavirus] and would be the subject of clinical trials,” he says. But until such compounds can be developed and tested, De Clercq says he is hopeful that remdesivir—an experimental drug that was originally developed to treat Ebola and has also proved effective against the SARS and MERS viruses in vitro—could be effective. (Gilead, which manufactures remdesivir, developed tenofovir and other antiviral drugs based on compounds De Clercq co-discovered.)

Source: https://www.scientificamerican.com/