On November 19, 2020, the World Health Organization (WHO) recommended against the use of the antiviral Remdesivir (also known as Veklury) due to lacking evidence, following months of controversy regarding the utility of the drug. This decision was made based on four trials, including one conducted by the WHO, called the Solidarity trial, which is the largest so far and includes over 5,000 patients being used to study Remdesivir.
The pre-print study found that Remdesivir (along with Hydroxychloroquine, Lopinavir and Interferon) regimens appeared to have little or no effect on hospitalized COVID-19, measured by by rates of overall mortality, initiation of ventilation, and the duration of stay in the hospital. The study also found that that Remdesivir does not reduce COVID-19 deaths. The trial studied data from 405 hospitals in 30 countries, and randomly assigned more than 11,000 people hospitalized with COVID-19 to assess Remdesivir and three other drugs. 301 of 2,743 people hospitalized with COVID-19 taking Remdesivir died, compared with 303 of 2,708 who were not taking Remdesivir, demonstrating that Remdesivir does not have a statistically significant mortality benefit.
Despite this recommendation by the WHO, Remdesivir continues to be recognized as a credible treatment for COVID-19 among hospitalized individuals, including in the U.S., Japan, and Germany. On October 22, 2020, the U.S. Food and Drug Administration (FDA) approved Remdesivir based off of the evidence of three randomized controlled trials. Remdesivir was the first officially approved treatment of COVID-19 within the U.S. The approval followed the FDA’s Emergency Use Authorization (EUA) for Remdesivir on May 1. Remdesivir was developed by pharmaceutical company Gilead.
The other three studies the WHO panel reviewed evidence for to make their decision found more positive evidence regarding Remdesivir, but were smaller in size. One clinical trial, conducted by the National Institute of Allergy and Infectious Diseases, assessed COVID-19 recovery time within 29 days of being treated. The trial looked at 1,062 hospitalized subjects with mild, moderate, and severe COVID-19 who received Remdesivir versus those who did not. The median time to recovery from COVID-19 for those who received Remdesivir was 10 days compared to 15 days for those who did not, a statistically significant difference. The odds of clinical improvement were also higher for those who took Remdesivir at Day 15 compared to those who did not. This difference, however, was not statistically significant.
A second study found that the odds of a subject’s COVID-19 symptoms improving were higher if they had taken Remdesivir compared to if they had received the standard of care. If the drug was taken for 10 days rather than 5 days, the chances increased more, but not to a statistically significant extent. The third, separate study found that a patient’s odds of their COVID-19 symptoms improving were similar for those taking Remdesivir for 5 days as those for 10 days, and that there were no statistically significant differences in recovery or mortality rates between the two groups. Once again, these studies are smaller in size than the WHO Solidarity trial.
Favipiravir is also considered to be a possible treatment for COVID-19. A small study showed the virus being reduced faster with the drug in comparison to other medications. Without further study, there is not enough evidence suggesting effectiveness and safety.
Many studies for COVID-19 treatments remain underway, and it is too early to determine which additional ones may be effective therapeutic options for COVID-19 patients. When Favipiravir or any medication not officially approved is prescribed, it is important that medical providers monitor the patient's clinical condition noting effectiveness and possible negative side effects.