ENA Respiratory Begins Part B Dosing in INNA-051 Phase IIa Community Study Designed to Protect Against Symptomatic Viral Respiratory Infections

Melbourne, Australia, 15 September 2026 – ENA Respiratory, a clinical-stage pharmaceutical company developing host defence enhancers for the prevention of complications associated with respiratory viral infections in at-risk populations, today announces it has dosed the first participants in Part B of its Phase IIa community study of INNA-051.

INNA-051 is a virus-agnostic, once-weekly, dry powder nasal spray that primes the natural antiviral host defences in the nose where common respiratory viruses like rhinovirus, flu, RSV and coronaviruses primarily enter, enabling the body to respond more quickly when challenged. INNA-051 therapy aims to reduce the incidence of complications in patients at higher risk of severe illness.

The ‘POSITS’ study (NCT07222670) is evaluating the safety, tolerability and efficacy of up to three months’ treatment with INNA-051 and assessing its impact on the incidence, duration and severity of symptomatic infections caused by common respiratory viruses in young adult participants at risk of illness due to living or working in crowded environments

Part A of the study was successfully completed in 200 participants in May with no safety concerns identified following four weeks of weekly dosing.

Part B will recruit up to 900 participants during this North American respiratory virus season, with participants dosed for three months across five sites in the USA, including the Center for Vaccine Development and Global Health (CVD) at the University of Maryland, Baltimore, the Naval Medical Research Command (NMRC) Clinical Trials Center, Bethesda, Maryland and three Accellacare clinical sites in North Carolina. Recruitment will continue to target those in severely crowded households, residents of university housing, military personnel living in barracks, childcare center workers and/or those living with or caring for a child aged 10 or less attending school or day care (https://enarespiratory.com/inna-051/clinical-trials/).

ENA Respiratory’s Consultant Medicine Development Lead, Ruth Tal-Singer, PhD said: “The start of large Part B of our study is another important milestone in the development of INNA-051. Complications from respiratory viral infections continue to place a huge burden on patients and healthcare systems globally. By boosting the body’s natural host defence pathways, we believe INNA-051 could offer new hope to millions of vulnerable patients worldwide and we look forward to adding to the clinical evidence of its potential through this study.”

-ENDS-

About ENA Respiratory

ENA Respiratory is a clinical-stage pharmaceutical company tackling respiratory viral infections through the development of host defence enhancers which locally prime and boost the body’s natural first line of defence against invading pathogens. Being virus-agnostic, ENA’s approach offers a solution to protect against common and emerging respiratory viruses for which vaccines or direct-acting antivirals have limitations or do not exist.

The company’s lead product, INNA-051, is being developed as a convenient, once-a-week nasal dry powder product to reduce the impact of viral respiratory infections and prevent severe complications in at-risk populations, including the elderly, those with an underlying medical condition (including chronic lung conditions, diabetes, kidney disease, and cardiovascular disease) and individuals with occupational risk (e.g. first responders, military or essential services personnel).

INNA-051 is a potent agonist of toll-like receptor 2/6 (TLR2/6) which plays a key role in recognising pathogens and potentiating innate immune responses. With a safety profile supporting seasonal prophylaxis use, it has demonstrated accelerated virus clearance and stimulation of antiviral host defences, including IFN Type I & III responses, in a Phase IIa proof-of-principle study using a human influenza-challenge model.

Headquartered in Melbourne, Australia, with operations in the USA, ENA’s Investors include Brandon Capital, Flu Lab, the Gates Foundation, the Minderoo Foundation, Stoic Venture Capital and Uniseed. The Company is partnered with the US COPD Foundation to support patient-focused clinical development of INNA-051 in COPD and has been awarded contracts from the U.S. Government. It is an alumni member of BLUE KNIGHT™, a joint initiative between Johnson & Johnson Innovation and BARDA designed to accelerate novel potential solutions for future pandemics.

For more information, please visit https://enarespiratory.com

For further information, please contact:

Media – Australia

Ruth Heenan, E: [email protected] M: +61 (0)416 565 332

Media – International

Charles Consultants

Sue Charles, E: [email protected] M: +44 (0)7968 726585

Chris Gardner, E: [email protected] M: +44 (0)7956 031077