Kenyan scientist's drug could treat Covid-19, shows study

Dr George Njoroge, an award-winning scientist.
Dr George Njoroge, an award-winning scientist.
Photo credit: FILE I NATION MEDIA GROUP

What you need to know:

  • Boceprevir has demonstrated particularly good potency in inhibiting COVID-19 proliferation in cells.
  • Jun Wang and a team of researchers  at the University of Arizona  in  Tucson, Arizona, recently published peer reviewed findings which showed  that Boceprevir had a strong binding to the enzyme that coronavirus uses to process its proteins.

Researchers have found that Boceprevir (Victrelis), a drug developed by Kenyan Scientist, Dr George Njoroge and his team at Merck Pharmaceutical Company for treatment of Hepatitis C virus, has demonstrated particularly good potency in inhibiting COVID-19 proliferation in cells.

This comes after Jun Wang and a team of researchers  at the University of Arizona  in  Tucson, Arizona, recently published peer reviewed findings which showed  that Boceprevir had a strong binding to the enzyme that coronavirus uses to process its proteins.

According to BioRxiv, which is a global pre-print server for biology, the researchers conducted a structure-activity relationship study of boceprevir-based molecules to find antiviral drug candidates targeting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) protease MPro.

They explained that currently available treatments for coronavirus are not very effective and so drug repurposing research efforts are needed to identify drug candidates that could be effective as Covid-19 treatments, particularly MPro inhibiting small molecules.

“Interestingly, Pfizer’s new antiviral pill Paxlovid (Nirmatrelvir), which was given emergency use authorisation in late December to treat mild to moderate Covid-19 by FDA, has great similarity to Boceprevir.

“This is very important since Paxlovid has been found to be 89 per cent effective when taken within the first three days of symptoms and 88 per cent effective when taken every 12 hours for the first five days,” Dr Njoroge said in an exclusive interview.

Brandon Anson, a graduate student in Professor Andrew Mesecar’s laboratory at Purdue University in Indiana, US, has further determined that the X-ray structure of Covid-19 main protease (enzyme) is bound to Boceprevir.

“The structure has been deposited in the protein bank under PDB code 6WNP. 

The information generated by these two groups is very important and great step forward in discovering medicines to treat Covid-19 since it provides research scientists with an understanding of the mechanism on how these elusive viruses manage to replicate themselves.

“The information presented here provides an important handle that would allow researchers to design and synthesise even more potent drugs and certainly ones that circumvent any viral resistance in case it occurs,” Dr Njoroge explained.

Experts are extremely excited with their result and they recommended that this drug should further be evaluated in animal models and human clinical trials but since Boceprevir is an FDA-approved, the dose, toxicity, formulation, and pharmacokinetics properties are already known, which will greatly speed up the design of follow-up studies thus expediting the process of bringing new drugs to patients who desperately need them.

Dr Njoroge believes this is very important as several other drugs are currently being evaluated in clinical trials.

A polymerase antiviral inhibitor, Remdesivir, a drug by the company Gilea, initially invented for treatment of Ebola, although without much success, and hydroxychloroquine, are two drugs that are in the fore front of these investigations.

In the vaccine arena, Moderna, a company in Boston US, is utilising its messenger RNA-therapy platform to discover potential candidate in this endeavour.

“I am requesting the World Health Organisation (WHO) to review the available data and determine whether this drug could be added to the list of candidates that are undergoing clinical trials as a single agent or in combination with other antiviral inhibitors such as Remdesivir.

The trials could be done either in US or here in Kenya,” he says.

“Now that preliminary results demonstrate that Boceprevir is a potent inhibitor of the deadly Covid-19, the next step is to determine its utility in the treatment of this life-threatening disease by undertaking rigorous double blind randomised controlled clinical trials.

“This kind of clinical trial will unambiguously determine whether this drug, as single or combined agent, is effective in treating Covid-19 disease in patients. This will go well with the current paradigm where scientists are testing older drugs for new indications – a function dubbed as drug repurposing.”

Boceprevir was the first protease inhibitor to be approved by FDA for treatment of Hepatitis C, a rather deadly disease that infected about 180 million people worldwide.

“My team worked diligently to understand the way the virus invaded and ultimately replicated in its human host cells. Hepatitis C, a positively single stranded RNA virus just like Covid-19, was very elusive and its target protease had barely available sites prone to scientific interceptions.”

He discloses that it took 15 years for the team to carry out this rather complex research work that eventually led to discovery of Boceprevir.

“To get to this candidate, my group interrogated more than 5,000 other molecules that never met the required properties that were needed for the drug to be effective and safe in human beings. We achieved our goal by a drug that was effective in treating the deadly Hepatitis C virus.  Data was presented to the FDA advisory committee that had to make decision on whether a drug was to be approved or not and with a vote of 18-0, the drug was approved by FDA.  On July 18, the European commission took a similar action and approved Boceprevir.”

Asked how he felt about the journey to that major discovery, “Dr Njoroge says: “Discovering a drug is not rocket science, it is more complicated.”

The Kenyan expert and his team were inducted into the coveted “Hall of Fame” as 2012 Heroes of Chemistry by the prestigious American Chemical Society.