Promising Australian COVID-19 preventative nasal spray commences Sydney Phase I clinical trial, seeks participants

  • First-in-class, fast-acting nasal spray designed to boost innate immunity against respiratory viruses including COVID-19, influenza and the common cold, seeks participants for first in-human safety trial in Sydney
  • Australian biotech, ENA Respiratory, recently secured AU$32 million investment to clinically develop its therapy, INNA-051
  • INNA-051 reduced COVID-19 replication by up to 96 percent in gold-standard, peer-reviewed, study performed by Public Health England (PHE) scientists

Sydney, Australia, 14 July 2021 – ENA Respiratory, the Australian biotech company developing a first-in-class nasal spray for the prevention of COVID-19, has initiated a Phase I human safety study in Sydney.

ENA Respiratory’s therapy, INNA-051, activates a person’s innate immunity in the nose, the primary entry portal of most respiratory viral infections. It reduced COVID-19 replication by up to 96 percent in a gold-standard, peer-reviewed pre-clinical study performed by Public Health England.

The company is seeking 100 healthy Sydneysiders to participate in its Phase I human safety study which it hopes to complete by the end of September.

“Sydneysiders need no reminder of the continued threat COVID-19 poses to our way of life and participating in this clinical study is a way to contribute to the global fight against the pandemic,” says Dr Charlotte Lemech, Principal Investigator on the ENA Respiratory study and Medical Director at Scientia Clinical Research in Sydney.

“Despite the challenges of the current lockdown in Sydney, we have put in place additional safety procedures and our trial is continuing. We are seeking the support of any healthy adults aged 18 – 55 years to participate. We have dosed a number of cohorts so far and they are tolerating the therapy well.”

INNA-051 is a fast-acting and convenient nasal spray that could be used prior to, or shortly after, exposure to a virus, prompting the body to respond faster to protect patients from illness and reduce the chance of community spread.  

“Vaccines have been slowing the spread of COVID-19 in a number of countries, but the world remains at risk with the emergence of variants with increased transmissibility, such as the Delta variant, first discovered in India. Being agnostic to specific virus or viral variants is one of the potential key strengths of INNA-051,” says Dr Christophe Demaison, co-founder and CEO of ENA Respiratory.

“As we continue to combat current and emerging COVID-19 variants, there is a significant need for convenient therapies that boost protection in at-risk populations, such as the elderly, and those with known COVID risk factors, such as obesity, diabetes and hypertension. By stimulating the innate immune response, we hope to create an additional line of defense against COVID-19 and other respiratory viral infections.”

INNA-051 works by priming the innate immunity in the nasal cavity to rapidly eliminate viruses and other pathogens at the site of infection before these spread to other parts of the body.1&2 Epithelial cells that line the nasal cavity play a key role in sensing and initiating innate immune responses to respiratory pathogen threats.3 In the case of COVID-19, innate immune responses are triggered within 48 hours following virus exposure and symptom onset. By contrast, the adaptive immunity which is triggered by vaccination or virus exposure and leads to the production of neutralizing antibodies takes about two weeks to establish.4

INNA-051 has been shown in preclinical studies to be fast acting. It has the potential to reduce the time required for nasal epithelial cells to initiate the innate immune responses following virus exposure, providing an advantage to the body in its fight against the virus.

The Phase I study in Sydney is a randomized, double-blind, placebo-controlled, single and multiple ascending dose study. Its goal is to investigate the safety and tolerability of INNA-051 in healthy adults ages 18 to 55 years old. The trial will also assess pharmacokinetics and pharmacodynamics of the therapy in study participants.

If results from the gold-standard animal study carried out by Public Health England (PHE), and published in the peer-reviewed journal EBioMedicine5, are replicated in humans, INNA-051 could be used to protect against COVID-19 after exposure to it and its variants. Non-clinical studies also suggest INNA-051 has the potential to protect against other viral illnesses, such as influenza and the common cold.

“As a broad-spectrum therapy, INNA-051 could be used in reducing illness associated with other common respiratory viruses, such as flu or common cold that circulate annually” says Dr Chris Smith, Chairman of ENA Respiratory. “The easy-to-use nasal spray could be helpful in protecting at-risk populations, such as the elderly or patients with chronic respiratory diseases.”

ENA Respiratory recently secured AU$32m investment from life science investor, Brandon Capital Partners and leading philanthropic organisation, Minderoo Foundation, with co-investment from Australian university venture fund, Uniseed, to support the clinical development of INNA-051.

Those from the Sydney region who are interested in participating the ENA Respiratory Phase I safety study can go here to find our more. Those successfully recruited into the study will be paid for their time.



About ENA Respiratory and INNA-051
ENA Respiratory is aiming to transform the treatment and prevention of respiratory viral infections in at-risk populations. The company is based in Melbourne and Sydney, Australia.

INNA-051 is a potent innate immune agonist that targets the receptor TLR2/6. It is being developed for intranasal delivery to target the primary entry site of viral respiratory infections as most respiratory viruses, including SARS-CoV-2 and influenza, initially infect and replicate in nasal mucosal epithelial cells which express TLR2 and TLR6 on their surface. Topical nasal administration of INNA-051 and close analogues have been shown in pre-clinical studies to protect treated animals from SARS-CoV-2 (causative agent of COVID-19), influenza virus (flu) and rhinovirus (common cold) infections. Key features of INNA-051 intranasal administration include limited minimal or no systemic bioavailability, minimal or no systemic pro-inflammatory cytokine release, no direct type I interferon upregulation, durable immune response supporting twice-weekly administration and compatibility with vaccine and intranasal corticosteroids. For more information, please visit

About Uniseed
Uniseed is Australia’s longest running early-stage commercialisation fund that makes investments in research emanating from five of Australia’s leading research organisations – The University of Queensland, The University of Sydney, The University of New South Wales, The University of Melbourne and the CSIRO. Uniseed is a mutual fund, owned by research organisations, for research organisations. The fund facilitates the commercialisation of its research partners’ most promising intellectual property and secures targeted investment in resulting products and technologies. Uniseed has supported 60 start-up companies to date, being the seed investor in most of these. For more information, visit:


  • Girkin, J et al. TLR2-mediated innate immune priming boosts lung anti-viral immunity. European Respiratory Journal. 2020. 2001584; DOI: 10.1183/13993003.01584-2020
  • Deliyannis, G. et al. TLR-mediated activation of innate responses in the upper airways confers antiviral protection of the lungs. JCI Insight. 2021. 6(5):e140267.
  • Hewitt, R.J., Lloyd, C.M. Regulation of immune responses by the airway epithelial cell landscape. Nat Rev Immunol. 2021. 21, 347–362
  • Vetter, P et al. Daily Viral Kinetics and Innate and Adaptive Immune Response Assessment in COVID-19: a Case Series. mSphere. 2020. 5  6.
  • Proud PC et al. Prophylactic intranasal administration of a TLR2/6 agonist reduces upper respiratory tract viral shedding in a SARS-CoV-2 challenge ferret model. EBioMedicine. 2021 Jan;63:103153. doi: 10.1016/j.ebiom.2020.103153. Epub 2020 Dec 3.