ENA Respiratory announced that “an unexpectedly large proportion of participants having pre-existing immunity to the challenge strain” resulted in difficulties interpreting data from a Phase 2a flu challenge study of its INNA-051 pegylated TLR2/6 agonist nasal spray. According to the company, dosing with “a substantial dose of H3N2 influenza A virus” failed to infect subjects who received a placebo nasal spray at the anticipated rates. After excluding participants with pre-existing immunity, however, the company said that treatment with INNA-051 resulted in a statistically significant reduction in the duration of infection.
The Phase 2a study evaluated two doses of a liquid intranasal formulation of INNA-051 against placebo in 123 participants. According to the study record on clinicaltrials.gov, the primary endpoint was change in viral load under the curve at Day 8 as measured by qRT PCR.
ENA Respiratory Managing Director and CEO Christophe Demaison commented, “This study further supports the concept that boosting the local innate immune response to common respiratory viruses has potential clinical benefit. In this study, INNA-051 was found to be safe and to significantly impact the course of infection. We are eager to investigate INNA-051’s clinical benefit in the context of natural viral respiratory tract infections in individuals at increased risk of more severe illness.”
Chief Medical Officer Scott White said, “Many people around the world have now been impacted by a ‘tripledemic’ of flu, RSV and SARS-Cov-2 viruses that have been circulating together in recent months. The surge in illness and hospitalization demonstrates the urgent need for a broad-spectrum treatment to boost immunity against common respiratory illnesses, and these data suggest INNA-051 is a promising option.”
Read the ENA Respiratory press release.