A novel nasal spray treatment, being developed by Australian biotech Ena Respiratory, produced promising results against COVID-19 in an animal study performed by Public Health England (PHE) scientists.

The nasal spray, INNA-051, reduced COVID-19 viral replication by up to 96% in the animal study led by PHE’s deputy director Professor Miles Carroll.

INNA-051 stimulates the innate immune system – the first line of defence against pathogens into the body. The treatment has the potential to be used to prevent infection in at-risk populations, including healthcare workers and the elderly, according to Ena.

It is a synthetic small molecule that would be self-administered via nasal spray, taken once or twice a week for the prevention of COVID-19.

So far, Ena has raised AU$11.7m from Australian investors to progress the INNA-051 clinical development programme. If all goes to plan in upcoming toxicity studies and regulatory approval, the company is hoping to be ready to test INNA-051 in human trials in less than four months.

“We’ve been amazed with just how effective our treatment has been. By boosting the natural immune response of the ferrets with our treatment, we’ve seen a rapid eradication of the virus,” said Christophe Demaison, managing director of Ena Respiratory.

“If humans respond in a similar way, the benefits of treatment are two-fold. Individuals exposed to the virus would most likely rapidly eliminate it, with the treatment ensuring that the disease does not progress beyond mild symptoms.

“This is particularly relevant to vulnerable members of the community. In addition, the rapidity of this response means that the infected individuals are unlikely to pass it on, meaning a swift halt to community transmission,” he added.