San Francisco (IANS) The most promising drug to potentially treat coronavirus -- Gilead Sciences' remdesivir -- is being given a second shot at clinical trials after three seriously-affected patients in the US treated with remdesivir recovered albeit with some side effects.
According to a report in Statnews on Monday, remdesivir is now being tested in five COVID-19 clinical trials and the first trial results are expected next month.
As of now, there are no approved therapies for any coronavirus infection, and "remdesivir is the farthest along in the development process of any candidate."
"There's only one drug right now that we think may have real efficacy. And that's remdesivir," Bruce Aylward of the World Health Organisation (WHO) said.
A randomised, controlled clinical trial to evaluate the safety and efficacy of the investigational antiviral remdesivir in hospitalised adults diagnosed with COVID-19 began at the University of Nebraska Medical Center (UNMC) in Omaha late last month.
According to the US National Institute of Health (NIH), this was the first clinical trial in the US to evaluate an experimental treatment for COVID-19.
A paper describing the first 12 patients with COVID-19 in the US started circulating ahead of an official peer review.
"All three patients treated with remdesivir recovered, but they also reported significant gastrointestinal symptoms. Investigators also noticed elevated liver enzyme levels in their blood samples," according to a report in The Motley Fool.
Remdesivir is an investigational broad-spectrum antiviral treatment.
It was previously tested in humans with Ebola virus disease and has shown promise in animal models for treating Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS), which are caused by other coronaviruses.
Clinical trials of remdesivir are also ongoing in China.
"Drug discovery and development is usually a very long and tedious process and you could have many failures on the path to an approved product," Tomas Cihlar, Gilead's vice president of virology, told STAT.
As for remdesivir's chances in COVID-19, Cihlar said: "It would be wonderful if it works. But it needs to be proven."
Remdesivir, developed by US biotech company Gilead Sciences, has been able to advance into clinical studies so quickly for two key reasons.
"For one, thanks to its use in Ebola, it was known to be generally safe in humans. And two, it had a large body of preclinical evidence - that is, data from studies in cells in lab experiments and in infected animals - that indicated it could temper coronavirus infections," said the report.
The five clinical trials of remdesivir in COVID-19 patients include two run by Chinese scientists, one sponsored by the National Institute of Allergy and Infectious Diseases (NIAID) and two sponsored by Gilead in countries around the world with a large number of cases.
Remdesivir cripples an enzyme called RNA polymerase that is used by many viruses to copy themselves. It does not specifically target SARS-CoV-2, the virus that causes COVID-19 but it worked well in test tube and animal studies of human coronaviruses, cousins of SARS-CoV-2 called severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS).
In total, there are 35 active drug development programmes currently on in North America, Europe and China.