Melbourne-based ENA Respiratory has secured $22.4 million in Series B financing to advance its investigational nasal spray therapy INNA-051 into Phase II clinical development. The funding round welcomed new investment from the Gates Foundation and Flu Lab, alongside continued backing from existing investors Brandon Capital, Uniseed, and Stoic Venture Capital.
Novel Approach to Respiratory Virus Prevention
INNA-051 represents a virus-agnostic approach to respiratory infection prevention, designed as a once-weekly dry powder nasal spray that primes the body's natural antiviral defenses in the nose, where viruses such as colds, flu, RSV, and coronaviruses typically enter. The therapy aims to reduce the duration and severity of symptomatic infections and prevent progression to the lungs.
The investigational treatment is a potent agonist of toll-like receptor 2/6 (TLR2/6), which plays a key role in recognizing pathogens and potentiating innate immune responses. In a Phase IIa proof-of-principle study using a human influenza-challenge model, INNA-051 demonstrated accelerated virus clearance and stimulation of antiviral host defenses, including IFN Type I & III responses.
Phase II Community Trial Design
The upcoming Phase II community study, designated POSITS, will evaluate the safety, tolerability, and efficacy of up to three months' treatment with INNA-051. The trial will assess the therapy's impact on the incidence, duration, and severity of symptomatic infections caused by common respiratory viruses, including influenza, RSV, rhinovirus, and coronaviruses.
The study will recruit up to 1,100 young adult participants at risk of illness due to living or working in crowded environments and will be conducted during the 2025-2026 North American respiratory virus season. Justin Ortiz, Professor of Medicine at the University of Maryland's CVDGH, will serve as Principal Investigator for the trial.
Addressing Significant Medical Need
Seasonal respiratory infections impose a substantial burden on healthcare systems and the economy, driving costly hospitalizations and workplace absences. The impact is particularly significant for patients with underlying medical conditions including asthma, COPD, heart disease, kidney disease, diabetes, primary immunodeficiency, and cancer, who face a much higher risk of complications. In the U.S., respiratory-related viral infections result in over one million hospitalizations and up to 200,000 deaths annually.
Research conducted by the patient advocacy group Global Allergy & Airways Patient Platform, supported by ENA, surveyed more than 3,000 U.S. adult respondents with relevant comorbidities and found strong interest in a convenient preventative option like INNA-051. A majority of those who identify themselves as high risk for hospitalization or emergency visits due to viral respiratory infections indicated they would use a product such as INNA-051 once a week during winter months.
Leadership Perspectives
"This funding marks a major milestone for ENA Respiratory as we advance INNA-051 into a community Phase II trial," said Christophe Demaison, CEO of ENA Respiratory. "With an international investor syndicate and ongoing support from our Australian investors, we are now in a strong position to evaluate the impact of our once-weekly powder nasal spray, which stimulates the body's natural antiviral defenses, in a community setting and moves us closer to bringing it to the patients who need it most."
Chris Smith, Non-Executive Director and Brandon Capital partner, noted: "Brandon Capital has supported ENA Respiratory since its earliest days because we recognized the potential of INNA-051 to transform the prevention and management of respiratory infections. With this new round of funding and the upcoming Phase 2 trial in the United States, ENA Respiratory is well on its way to delivering a therapy that could protect millions of vulnerable people worldwide."
