ENA Respiratory Advances INNA-051 Into Larger Phase IIa Study After Positive Safety Review

New updates have been reported about ENA Respiratory.

ENA Respiratory has cleared a key development hurdle for its lead asset INNA-051, completing Part A of a Phase IIa community study and securing Safety Review Committee approval to move into a substantially larger Part B. The once-weekly, dry powder nasal spray is designed to boost innate antiviral defences in the nasal passages, aiming to cut the incidence, duration and severity of symptomatic respiratory infections such as influenza, RSV, rhinovirus and coronaviruses, particularly in higher-risk populations.

Part A of the POSITS trial enrolled 200 young adults at five U.S. sites, including the Center for Vaccine Development and Global Health at the University of Maryland and the Naval Medical Research Command, and concluded four weeks of dosing without safety concerns, de-risking longer prophylactic use. Part B, planned for the next North American respiratory virus season, will expand to 900 participants dosed over three months in crowded living and working environments, offering ENA Respiratory a critical data set on real-world community efficacy and safety that will inform future regulatory strategy and partnering discussions.

INNA-051, a toll-like receptor 2/6 agonist, is being positioned by ENA Respiratory as a virus-agnostic prophylactic option where vaccines or direct-acting antivirals are inadequate or unavailable, with potential applications in older adults, patients with chronic conditions and occupationally exposed groups. The company, headquartered in Melbourne with U.S. operations, has previously shown accelerated virus clearance and robust interferon Type I and III responses in a human influenza challenge model, strengthening the biological rationale for seasonal and pandemic use cases.

Backed by investors including Brandon Capital, Flu Lab, the Gates Foundation, the Minderoo Foundation, Stoic Venture Capital and Uniseed, ENA Respiratory is leveraging non-dilutive support from U.S. Government contracts and its BLUE KNIGHT alumni status to accelerate development and pandemic preparedness positioning. Its partnership with the U.S. COPD Foundation provides a pathway to expand INNA-051 into chronic lung disease indications, potentially widening the addressable market and supporting long-term revenue prospects if upcoming Phase IIa data confirm safety and clinically meaningful reductions in respiratory viral illness burden.