China-headquartered Ark Biosciences has announced positive results from the Phase III AIRFLO study for its novel antiviral drug ziresovir (AK0529). The study evaluated the efficacy and safety of ziresovir in hospitalized infants with respiratory syncytial virus (RSV) infection. The drug achieved its primary endpoint of a significant reduction in symptom severity (S&S) score compared to a placebo and also met the key secondary endpoint of viral load reduction.
Study Design and Results
The randomized, double-blind, placebo-controlled, multi-center Phase III study assessed the drug in infants aged 1 to 24 months with moderate to severe RSV infection in China. Results showed that ziresovir demonstrated rapid clinical efficacy, with a 30% improvement in symptom scores compared to the placebo group on the third day of treatment. In the high-risk population of infants under six months old, ziresovir achieved a 55% improvement in symptom scores. Additionally, ziresovir significantly shortened intensive care unit (ICU) treatment time for patients with severe RSV-related diseases (3 days vs. 8 days).
Antiviral Efficacy and Safety Profile
Ziresovir also exhibited significant antiviral effects, with a 77% reduction in viral load on the fifth day of treatment compared to the placebo group. Throughout the treatment period, viral load remained significantly lower in the ziresovir group. The AIRFLO study further confirmed the good safety and tolerability of ziresovir, with no significant difference in adverse event incidence between the ziresovir and placebo groups.
Global Significance and Regulatory Milestones
Ziresovir is the world’s first oral RSV drug to complete a Phase III pivotal study and the first home-grown pediatric drug being developed globally. The drug previously received breakthrough therapy designation (BTD) from China’s National Medical Products Administration, highlighting its potential to address a significant unmet medical need in pediatric RSV infections.-Fineline Info & Tech