A direct-acting antiviral therapy to treat COVID-19

The Griffith University COVID-19 antiviral therapy research team Professor Kevin Morris, Dr Adi Idris, Professor Nigel McMillan, Dr Arron Supramanin and Mr Yusif Idres.

An international team of scientists from Menzies Health Institute Queensland (MHIQ) at Griffith University and City of Hope, a research and treatment centre for cancer, diabetes and other life-threatening diseases in the US, has developed an experimental direct-acting antiviral therapy to treat COVID-19.

 

Traditional antivirals, such as Tamiflu®, zanamivir and remdesivir, reduce symptoms and help people recover earlier.

This next-generation antiviral approach uses gene-silencing RNA technology called siRNA (small-interfering RNA) to attack the virus’s genome directly, as well as lipid nanoparticles designed at Griffith and City of Hope to deliver the siRNA to the lungs—the critical site of infection. This stops the virus replicating.

“Treatment with virus-specific siRNA reduces viral load by 99.9 per cent,” co-lead researcher Professor Nigel McMillan, of MHIQ, said. “These stealth nanoparticles can be delivered to a wide range of lung cells and silence viral genes.

“Treatment with the therapy in SARS-CoV-2-infected mice improved survival and loss of disease. Remarkably, in treated survivors, no virus could be detected in the lungs.”

Fellow co-lead researcher Professor Kevin Morris, from both City of Hope and Griffith University, said: “This treatment is designed to work on all betacoronaviruses such as the original SARS virus—SARS-CoV-1—as well as SARS-CoV-2 and any new variants that may arise in the future, because it targets ultra-conserved regions in the virus’s genome.”

Professor McMillan added: “We have also shown that these nanoparticles are stable at 4°C 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.”

The results suggest that siRNA-nanoparticle formulations can be developed as a therapy to treat COVID-19 patients, as well as used for future coronavirus infections by targeting the virus’s genome directly.

“These nanoparticles are scalable and relatively cost-effective to produce in bulk,” Professor Morris said.

“This work was funded as an urgent call by Medical Research Futures Fund and is the type of RNA medicine that can be manufactured locally in Australia,’’ Professor McMillan said.

The research has been published in Molecular Therapy.