ENA Respiratory Announces Dosing of First Participants in Phase II Study of INNA-051 Nasal Spray Designed to Protect Against Symptomatic Viral Respiratory Infections

Melbourne, Australia, 29 January 2026 – ENA Respiratory, a clinical-stage pharmaceutical company developing antiviral host defense enhancers to minimize the impact of symptomatic viral respiratory infections, today announces it has dosed the first participants in its Phase II community study of INNA-051, [with the first participant dosing now completed].

INNA-051 is a virus-agnostic, once-weekly, dry powder nasal spray which primes the natural antiviral host defences in the nose where viruses like colds, flu, RSV and coronaviruses typically 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 (https://clinicaltrials.gov/study/NCT07222670) will evaluate the safety, tolerability and efficacy of up to three months’ treatment with INNA-051 and assess its impact on the incidence, duration and severity of symptomatic infections caused by common respiratory viruses, including influenza, RSV, rhinovirus, and coronaviruses in young adult participants at risk of illness due to living or working in crowded environments.

The study will recruit up to 1,100 generally healthy male and female participants who are at increased risk for exposure to viral respiratory infections. An initial 200-participant safety Phase A is being conducted during the current North American respiratory virus season, with weekly dosing for four weeks. This will be followed next season by a 900-participant Phase B with participants being dosed for three months.

Recruitment will 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. The first participants were dosed at the Center for Vaccine Development and Global Health (CVD) at the University of Maryland, Baltimore with additional participants being recruited at the Naval Medical Research Command (NMRC) Clinical Trials Center, Bethesda, Maryland.

Viral respiratory infections are a major global health problem, and the impact is most significant for patients with underlying medical conditions such as asthma, COPD, heart disease, kidney disease, diabetes, primary immunodeficiency and cancer, who face a much higher risk of complications.

ENA Respiratory’s CEO, Christophe Demaison, PhD said: “The start of the POSITS study is an important next step for ENA Respiratory and for the development of INNA-051. Our previous pre-clinical and clinical work has shown INNA-051 to have the potential to shorten the duration of symptomatic infections, prevent progression to the lungs, and reduce complications.

“There were over a million hospitalizations and up to 200,000 deaths in the U.S. in 2025 from respiratory-related viral infections in such patients last year. By boosting the body’s natural host defense pathways INNA-051 could offer a new option for millions of vulnerable patients worldwide and this study is an opportunity to add significantly to our evidence of its potential.”

-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, the company has raised US$33 million (AU$46 million) in financing from Brandon Capital, The Minderoo Foundation, Flu Lab and Uniseed. It is partnered with the US COPD Foundation to support patient-centered clinical development of INNA-051 in COPD and has been awarded a US$13.1 million contract from the U.S. Department of Defense. 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]

Media – International

Charles Consultants

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

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