Posted: 3 February 2026
ENA Respiratory has announced that the first participants have been dosed in its Phase II community study of INNA-051, a nasal spray designed to protect against symptomatic viral respiratory infections.
INNA-051 is a virus-agnostic, once-weekly, dry powder nasal spray which primes the natural antiviral host defences in the nose where viruses such as colds, influenza, respiratory syncytial virus (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 will evaluate the safety, tolerability and efficacy of up to three months’ treatment with INNA-051 and will assess its impact on the incidence, duration and severity of symptomatic infections caused by common respiratory viruses, including influenza, RSV, rhinovirus and coronaviruses. The study is being conducted in young adult participants at risk of illness due to living or working in crowded environments.
Up to 1,100 generally healthy male and female participants who are at increased risk for exposure to viral respiratory infections will be recruited. 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.
Commenting on the study, ENA Respiratory Chief Executive Officer 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 hospitalisations 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 defence 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.”
