ENA Respiratory has started dosing participants in its phase 2 community study of INNA‑051, a dry‑powder nasal spray designed to strengthen the body’s natural antiviral defences and reduce the impact of symptomatic viral respiratory infections.
The company confirmed that the first participants have now received the investigational treatment.
INNA‑051 is a once‑weekly, virus‑agnostic therapy intended to prime immune responses in the nose, where viruses such as colds, flu, RSV and coronaviruses typically enter. The aim is to help the body respond more rapidly to infection and lower the risk of complications in people more vulnerable to severe illness.
The POSITS study will evaluate the safety, tolerability and efficacy of up to three months of treatment with INNA‑051. It will also assess the spray’s effect on the incidence, duration and severity of symptomatic infections caused by common respiratory viruses in young adults at increased risk due to living or working in crowded environments.
Up to 1,100 generally healthy male and female participants will be enrolled. A 200‑participant safety phase A is under way during the current North American respiratory virus season, with weekly dosing for four weeks. A larger 900‑participant phase B will follow next season, with dosing over three months.
Recruitment is focused on people living or working in high‑exposure settings, including crowded households, university accommodation, military barracks and childcare centres. Initial dosing took place at the Center for Vaccine Development and Global Health at the University of Maryland, Baltimore, with further recruitment at the Naval Medical Research Command Clinical Trials Center in Bethesda, Maryland.
Christophe Demaison, CEO of ENA Respiratory, 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.”
He added: “There were over a million hospitalisations and up to 200,000 deaths in the US 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.”
