ENA Respiratory has achieved a significant milestone in the development of its antiviral host defense immune enhancer, INNA-051, with the successful completion of Phase Ib dosing in older adults. The dry powder intranasal formulation demonstrated favorable tolerability and effectively activated local innate immune pathways, marking a crucial step forward in addressing viral respiratory infections in vulnerable populations.
The Phase Ib trial enrolled 32 participants aged 60 and above, evaluating multiple ascending doses administered weekly over three occasions. The maximum dose tested was 900 mcg, representing a threefold increase from previous trials using the liquid formulation. Notably, the treatment was well-tolerated across all dose levels, with adverse events primarily characterized as mild and transient, affecting only the upper respiratory tract.
Enhanced Formulation Stability
A key advancement in this trial is the new dry powder formulation, which boasts an expected shelf life exceeding two years at room temperature. This improved stability represents a significant advantage for commercial viability and practical implementation in clinical settings.
Biomarker Evidence of Immune Response
Analysis of nasal samples from study participants revealed significant activation of innate immune pathways, including antiviral host defense mechanisms. These findings align with previous clinical observations using the liquid nasal spray formulation, suggesting consistent biological activity across formulations.
Ongoing Studies and Future Plans
The U.S. Department of Defense is funding an extension study in younger adults aged 18-45, with initial results from the 300 mcg cohort showing comparable safety and tolerability profiles to those observed in older adults. Complete study results are anticipated in Q2 2025.
"These results provide an excellent foundation for our planned Phase II Proof of Concept community infection study," stated Christophe Demaison, PhD, CEO of ENA Respiratory. "They reinforce INNA-051's potential as a convenient, commercially attractive, seasonally-delivered product that minimizes the impact of common viral respiratory infections and prevents serious complications."
Market Potential and Target Population
The development of INNA-051 addresses a significant medical need, particularly in the United States, where 34.3 million adults aged 60 and over have comorbidities that increase their risk for viral respiratory infections. The company is positioning the product as a preventive treatment against multiple respiratory viruses, including coronaviruses, seasonal influenza, rhinoviruses, respiratory syncytial virus, and human metapneumovirus.
ENA Respiratory is preparing for a Phase II community infection study, scheduled for Q4 2025, which will evaluate INNA-051's efficacy in reducing the incidence and duration of symptomatic infections caused by common respiratory viruses in young adults at risk for exposure in the United States.
