A nasal spray that can block viruses that cause the common cold and help prevent deadly secondary infections has cleared a major hurdle.
The drug, named INNA-051, is a once-weekly, dry powder nasal spray.
The precise make-up of the drug is a closely guarded secret, but it has been found to boost the immune system and antiviral defenses in the nose.
Newcastle virologist Nathan Bartlett, who helped develop the drug, said it had been through a long process of scientific refinement.
"That's the secret sauce. The intellectual property centres on the formulation and chemical composition," said Professor Nathan Bartlett, of Hunter Medical Research Institute and University of Newcastle.
The drug is a TLR2/6 agonist and a synthetic mimic of a bacterial lipopeptide, which is a molecule with a lipid connected to a peptide.
"They've tweaked the natural molecule to maximise stability and make it as perfect as they can," said Professor Bartlett, who was Newcastle's 2024 Citizen of the Year for his work on respiratory infections.
The drug boosts the innate immune system in the nose, where viruses like colds, flu, RSV, SARS-CoV-2 (which causes COVID) and other coronaviruses typically enter the body.
"It's augmenting your natural capacity to protect yourself from these viruses," Professor Bartlett said.
If approved for the pharmaceutical market, it would represent a significant shift in how protection from respiratory viruses is treated, especially for those at high risk of severe illness.
ENA Respiratory, the Melbourne-based clinical-stage pharmaceutical company that is developing the drug, said it had successfully completed part A of its phase two clinical trial.
This involved 200 participants in the US receiving the drug over four weeks to test its safety.
As no safety concerns were found, the study can progress to part B of the trial, which will recruit 900 participants later this year during the US winter.
Professor Bartlett said the drug was initially developed as "an adjuvant for a vaccine".
Professor David Jackson's lab developed the molecule at the Doherty Institute in Melbourne.
"They are vaccine specialists. They were looking at different immune stimulants to make their vaccines work better," Professor Bartlett said.
"They noticed that the adjuvant itself stimulated a protective response against influenza. They thought maybe it could be a standalone antiviral."
The Melbourne lab pitched this idea to Professor Bartlett.
"I looked at their data and thought it was a great idea. They said 'do you want to see if you can make it work'," he said.
"I said sure thing. I'd been interested in that mechanism for a long time," he said.
"It looked like it would stimulate immunity in the upper respiratory tract, particularly the nose.
"They asked me to design a program to prove it works or doesn't work. That's how my involvement started."
Professor Bartlett examined the drug's effect on coronaviruses and rhinoviruses.
"The Doherty guys continued looking at influenza. They sent it to the UK and showed it worked against SARS-CoV-2. That was all preclinical research," he said.
The research showed the drug was effective against all these viruses.
"My role in Newcastle was one of the preclinical leads working on initial validation of the drug and its effect on viruses. We worked on it for about five years," Professor Bartlett said.
"We were there at the start, getting the evidence needed to raise the money so they could go with a big clinical trial."
ENA Respiratory attracted $46 million in financing from Brandon Capital, Gates Foundation, Minderoo Foundation, Flu Lab and Uniseed to develop the drug.
It was awarded an $18 million contract from the US Department of War's program for chemical, biological, radiological and nuclear defense.
The military investment prompted the drug to be converted from a liquid spray to a dry powder, as a more stable, practical and longer-lasting product was needed.
Professor Bartlett said "if the phase two-B data is favourable, the next phase of development would depend on who takes it on".
"One possibility would be they sell the technology to a big pharma company," he said.
"They have the capacity to do further clinical studies required for the drug to go through a regulatory approval process."
The drug could then become available to patients.
"You hope all that work you did makes it through clinical development and eventually ends up in doctors' hands treating patients," Professor Bartlett said.
"It would protect those at high risk of nasty outcomes."
Recruitment for the phase two-B trial will target people in crowded households, university housing and military barracks.
It will also include childcare centre workers and those living with children 10 and under, attending school or daycare.
