Possible Treatments: Remdesivir

COVID19Treatment

Apr 29

The World Health Organization has launched the multinational trial ‘SOLIDARITY’ to search for the most promising candidate treatments and therapies. One of these treatments includes the drug Remdesivir. Initially a drug developed to combat Ebola, this post will discuss how the drug works and its applications in the fight against COVID-19.

*Disclaimer: Remdesivir is currently undergoing clinical trials for its efficacy in treating COVID-19 and is NOT a proven treatment. As of 29 April 2020, Dr. Anthony Fauci from the NIAID has announced promising results from a large preliminary trial in terms of patient recovery time, but large scale trials will still be pursued. Please do not attempt to self-medicate - any medication should be prescribed by a doctor and used under medical supervision.*

What is Remdesivir?

Remdesivir is an antiviral drug initially manufactured by Gilead Sciences to combat the Ebola virus. In the lab, this drug has shown to have combative ability against multiple families of viruses including filoviruses (e.g. Ebola) and other coronaviruses (e.g. MERS).

Remdesivir is a nucleotide analogue; a nucleotide that is created to mimic a naturally-occurring nucleotide in an organism.

Nucleotides are the building blocks of DNA and RNA, with each one containing a nitrogenous base, a five-carbon sugar, and a phosphate group (Check out the graphic to the right).

These strings of nucleotides that make up DNA and RNA write our entire genetic code and will include all of our cells’ instructions and blueprints.

Nucleotide analogues are often used in antiviral drugs as they can combat the virus’ ability to replicate in infected human cells. Remdesivir is a nucleotide analogue of adenosine (one of 4 different nucleosides that make up DNA).

The graphic to the left shows the differences in a molecule of Remdesivir and adenosine. They are very similar in structure which allows the drug to seamlessly integrate into the virus’ genetic code.

How does Remdesivir work?

It is important to first note how viruses infect, replicate, and spread in the body. “By nature, viruses do not have the right machinery to create copies of themselves and so, they must hijack our own body cells to do so. When a virus enters the body, it attaches to our body cells and takes control by re-wiring the cell’s instructions to make more copies of the virus instead of completing its normal healthy cell duties” (excerpt from one of our previous blog posts). The virus is able to do this by altering the cell’s DNA with its own viral RNA. RNA, like DNA, is also made up of nucleotides and is an intermediate instructional molecule between DNA and proteins.

Therefore alteration of cell DNA with virus RNA can alter the proteins our human cells will make.

Remdesivir combats SARS-CoV-2’s activity by interfering with its RNA polymerase, the recruiting molecule used in virus replication. The drug will cause the virus’ RNA polymerase to stop recruiting the RNA nucleotides, prematurely terminating the viral protein chain. This leads to the misproduction of the viral proteins and therefore its inability to make as many successful copies of itself, slowing down the virus’ replication and spread.

Success thus far…

*Please note: Clinical trials with varying results are in part due to the different nature of these clinical trials. Depending on the parameters of the trials, different conclusions can be drawn from each trial individually. For more info on how to interpret clinical trial info, check out this blog post*

In this study published in the New England Journal of Medicine (which took place globally and including patients from Canada, Europe, USA, and Japan), a group of 61 patients with severe COVID-19 symptoms were treated using Remdesivir. Of these 61 patients, 47% were discharged and 17 of the patients who were initially on mechanical ventilators saw an improvement in their oxygen-support.

In the lab, the drug has also been shown to be effective against the SARS-CoV-2 virus. This study published in Nature’s Journal of Cell Research showed that Remdesivir could block virus infection at low concentrations.

Most recently, in this large scale preliminary trial by the National Institute of Allergy and Infectious Disease, Remdesivir has shown to improve recovery time in COVID-19 patients by an average of 4 days.

Remdesivir is currently undergoing multiple clinical trials including those initiated by Gliead and others in countries such as China, the United States, and France. To keep up to date with these trials, you can visit Gilead’s site or stay tuned to our treatment news page.