Study reveals how exactly an investigational drug stops coronavirus

According to the findings published in the Journal of Biological Chemistry, remdesivir blocks a particular enzyme, RNA-dependent RNA polymerase, that is required for genome replication of the virus.

The novel coronavirus outbreak, a new strain of previously unidentified coronavirus in humans is rapidly spreading around the world, claiming more than 2,700 lives in China alone. As of now, there is no specific cure or vaccine for the virus, however, an investigational new drug developed by US biotech firm Gilead Sciences is being evaluated for the treatment of novel coronavirus, aka COVID-19.

A team of academic and industry researchers from the University of Alberta and Gilead Sciences have published new findings about how Remdesivir actually works in coronavirus patients. The investigational drug has demonstrated a potential activity in animal models against the viral pathogens Middle-East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS), which are also coronaviruses.

According to the new findings, remdesivir blocks a particular enzyme, i.e. RNA-dependent RNA polymerase required for genome replication of the virus. Once the drug is incorporated into the growing RNA chain, the virus can no longer replicate. 

“Even if you know a drug works, it can be a red flag if you don’t know how it works, " said Matthias Götte, a virologist and professor at the University of Alberta, Edmonton, who led the JBC study.

“We know the drug works against different coronaviruses, like MERS and SARS, and we know the novel coronavirus is very similar to SARS. So I would say I’m cautiously optimistic that the results our team found with remdesivir and MERS will be similar with COVID-19," he further added.

Götte said more than one drug will be needed to properly fight emerging diseases like COVID-19, as with HIV and hepatitis C virus infections. The team is now waiting for results from ongoing clinical trials with remdesivir, which are expected by the end of April 2020.

Following the U.S. Food and Drug Administration’s (FDA) rapid review and acceptance of its investigational new drug (IND) filing, Gilead has initiated two Phase III clinical trials to evaluate the safety and efficacy of remdesivir in adults diagnosed with COVID-19. 

Gilead said on Thursday that the new clinical studies expand the ongoing research into remdesivir, which includes two clinical trials in China’s Hubei province led by the China-Japan Friendship Hospital as well as the recently initiated clinical trial in the United States led by the National Institute of Allergy and Infectious Diseases (NIAID). 

Gilead’s primary focus is on rapidly determining the safety and efficacy of remdesivir as a potential treatment for COVID-19, and this complementary array of studies helps to give us a more expansive breadth of data globally on the drug’s profile in a short amount of time.

Merdad Parsey, MD, PhD, Chief Medical Officer, Gilead Sciences.

Gilead developed remdesivir as a response to the 2014 West African Ebola virus epidemic. The investigational drug is not yet licensed or approved anywhere globally and has not been demonstrated to be safe or effective for any use. 

The study published in the Journal of Biological Chemistry was funded by the Canadian Institutes of Health Research and the Alberta Ministry of Economic Development, Trade and Tourism.