Pharmaceutical companies are intensely focused on efforts to develop treatments for the coronavirus (COVID-19), but a study published in Nature identifies 21 existing drugs that scientists say can already significantly reduce its severity.
The scientists analyzed drugs that had shown indications that they could block the replication of the virus causing COVID-19. They narrowed down the list to 21 drugs that were effective against the virus at concentrations that could safely be given to patients.
The scientists — led by Sumit Chanda, Ph.D., professor at Sanford Burnham Prebys Medical Discovery Institute — discovered that four drug compounds worked in concert with remdesivir, a current standard-of-care treatment for the coronavirus.
“Remdesivir has proven successful at shortening the recovery time for patients in the hospital, but the drug doesn’t work for everyone who receives it. That’s not good enough,” Chanda said.
Remdesivir itself is a repurposed drug. It was developed by Gilead Sciences to treat ebola. It was not effective at doing that, but it has shown good results in treating coronavirus patients when combined with plasma antibodies from recovered patients.
Effective and affordable
The Nature study was designed to not only identify effective drugs but single out medications that are affordable. The researchers identified drugs that could be combined with remdesivir to treat people with severe cases of the virus, as well as drugs that could be taken on an outpatient basis at the first appearance of symptoms.
Of the existing drugs that were effective at blocking viral replication, the scientists found:
13 have previously entered clinical trials for other indications and are effective at concentrations, or doses, that could potentially be safely achieved in COVID-19 patients.
Two are already FDA approved: astemizole is used to treat allergies and clofazamine is a leprosy medication.
Four worked synergistically with remdesivir, including the chloroquine derivative hanfangchin A (tetrandrine), an antimalarial drug that has reached Phase 3 clinical trials.
Vaccine still months away
The researchers say their work can help expand current options for safely treating COVID-19.
“This report provides the scientific community with a larger arsenal of potential weapons that may help bring the ongoing global pandemic to heel,” Chanda said.
In their study, the research team noted that the development of an effective vaccine will probably take at least 12 to 18 months. Approval of a vaccine has been known to take as long as 20 years.
The researchers say repurposing known drugs may offer the best chance to deal with the virus in the months ahead, making it much less of a health threat.