COVID-19 treatment: Ebola drug Remdesivir reaches human trial phase

On 10 April 2020, Daniel O’Day, the CEO of Gilead Sciences, gave an update on the seven clinical trials that are ongoing in different parts of the world.

According to O'Day, it would be too soon to give any kind of results but as of now the drug, Remdesivir, has only been used on a compassionate basis for 53 critically ill patients and has turned out to be effective as they all survived after receiving the drug.

Other than China’s trial, which discontinued due to the low enrollment of patients, five other trials have been underway to find out the effectiveness, dosage and frequency of the drug. 

Two of the studies that are being done by the Gilead Sciences includes:

• A study on more than 400 critically ill people, which may be summarised by the end of April 2020.
• Another study on more than 600 moderately ill people, which may be summarised by the end of May 2020.

Another study by The National Institute of Allergy and Infectious Diseases includes more than 800 infected people in all three stages - critical, severe or moderate. It is assumed that the study might get published by the end of May 2020.

A global trial is being conducted by the World Health Organization to find out the effectiveness of the drug. The other trials include the INSERM trial which has recently begun in Europe. Both of these trials include more than 10,000 infected people and the trials may last longer the rest of the other trials. It is being anticipated that the trials might give out the results late after June 2020.

During the outbreak of Ebola, Gilead Sciences, a US-based pharma company, developed a drug called Remdesivir, to fight the Ebola virus. Remdesivir stopped the enzyme RNA polymerase which was necessary for the virus to multiply. Since the virus could not replicate, it eventually died. But the drug didn’t seem to work for the Ebola virus.

In the year 2017, scientists from Gilead tested the same drug against the different strains of coronavirus. The research was done in labs in test tubes and on rhesus macaque monkeys who were infected with MERS-CoV infection. The research showed that Remdesivir has the ability to inhibit the SARS and MERS viruses. The preclinical studies showed that Remdesivir could be effective for both the prevention and treatment of coronavirus infections.

On 4 April 2020, the CEO of Gilead Sciences, Daniel O’Day, stated that Remdesivir was still under investigation and being tested in multiple clinical trials which involve thousands of patients with COVID-19 across the world. Since it has not been approved by any supervisory authorities, it cannot be yet used for the treatment of COVID-19 until its safety and effectiveness are proved, he said. 

After the US Food and Drug Administration (FDA) gave approval to the human testing of Gilead’s investigational new drug, it has initiated two Phase 3 clinical studies to evaluate the safety and efficacy of Remdesivir in adults diagnosed with COVID-19.

The firm started to enrol patients from March 2020 and would enrol a total of approximately 1,000 patients from countries with a high prevalence of COVID-19 infection, in the initial phase of the studies.

In the first study, patients with severe manifestations of COVID-19 will be given the drug in two slots, that is, for five and 10 days, respectively. Doctors and researchers would then evaluate the safety and efficacy of both the dosing durations. 

In the second study, patients with moderate manifestations of COVID-19 will be given the drug in a similar dosing regimen as the first study. 

The patients, both with severe and moderate manifestations, will be given standard care alone throughout the study. 

This human trial of Gilead Sciences is being supported by the UK’s Medicines and Healthcare products Regulatory Agency (MHRA), National Institute for Health Research (NIHR) and the Department of Health and Social Care (DHSC).

There are a few other trials that are being conducted in other countries to discover the safety and efficacy of Remdesivir as a possible treatment for the novel coronavirus infection.

Two different clinical trials have been initiated by health authorities in China and are being coordinated by the China-Japan Friendship Hospital. The trials are being done in different places in Hubei province, where COVID-19 is said to have originated in a wildlife and seafood market.

One of those studies is assessing the effect of Remdesivir in patients who have been confirmed for COVID-19 infection and have developed severe clinical symptoms such as difficulty breathing. 

The other study would evaluate the effect of Remdesivir in patients who have confirmed COVID-19 infection and have been hospitalized but have not developed severe symptoms.

The National Institute of Allergy and Infectious Diseases which is a part of the National Institutes of Health (NIH), US, has also begun a Phase 2 trial which would have two groups of patients out of which one would receive the drug while the other would get a placebo.  

Another research is being done by INSERM, which is the French National Institute of Health and Medical Research. INSERM is following a master protocol developed by the World Health Organization to evaluate the effect of Remdesivir and other potential treatments for COVID-19 infections.