A team of Queensland scientists has co-developed a “gene-silencing” antiviral treatment that could effectively kill COVID-19 in what’s been dubbed an “important missing piece” in the arsenal against the virus.
Nigel McMillan and his team from the Menzies Health Institute at Griffith University, alongside scientists from City of Hope research centre in the US, say the “next-generation” antiviral approach could stop the virus from replicating in the lungs.
Professor McMillan said stage 1 clinical trials revealed the antiviral treatment reduced the viral load in mice lungs by 99.99 per cent.
While traditional antivirals, such as Tamiflu and remdesivir, reduce symptoms and help people recover earlier, this new technology uses small interfering RNA (siRNA) to attack the virus’s genome directly, stopping the virus from replicating.
Lipid nanoparticles, designed at Griffith University and City of Hope, will be used as the drug delivery vehicle to deliver the siRNA to the lungs.
Professor McMillan said the treatment had proved incredibly effective in mice trials.
“Treatment with virus-specific siRNA reduces viral load by 99.99 per cent,” he said.
“These stealth nanoparticles can be delivered to a wide range of lung cells and silence viral genes.”
The nanoparticles are injected into the bloodstream and head straight for the lungs, going into “just about every lung cell”.
“Where there’s a virus, it will find it, bind to the genome and destroy it,” Professor McMillan told ABC News.
“This is kind of like taking the engine out of your car. The car won’t go anymore. The virus is dead, it can’t replicate anymore.
“It doesn’t do anything to normal cells.”
Professor McMillan told ABC News that scientists had yet to identify how late they could treat someone, but the animal studies were encouraging.
“This allows the immune system to come and clean it all up and give you that ultimate cure … With that sort of reduction in viral load, people won’t transmit the virus and have a good chance of recovery,” he said.
“For all antivirals, the earlier you get it into someone, the better the outcome.”
The treatment can work on all betacoronavirus, including the original SARS virus, SARS-CoV-2 (the virus that causes COVID-19), and any new variants that could arise in the future because it “targets ultra-conserved regions in the virus’s genome”.
“We have also shown that these nanoparticles are stable at 4C for 12 months, and at room temperature for greater than one month, meaning this agent could be used in low-resource settings to treat infected patients,” Professor McMillan said.
The team is hoping to progress to the next stage of trials by the end of the year, and if proven effective, it could be made available commercially by 2022.