Aridis meets primary, secondary endpoints in Phase 2a study of AR-501

Aridis Pharmaceuticals announced preliminary top-line results from the randomized, double blinded, placebo-controlled Phase 2a study of AR-501, which evaluated the safety and pharmacokinetics of three ascending doses of AR-501 administered as an inhaled aerosol in cystic fibrosis patients with confirmed Pseudomonas aeruginosa bacterial and other potential infections. The study was conducted with funding support from the Cystic Fibrosis Foundation. AR-501 is being developed as a once-per-week inhaled dosing regimen that is self-administered using a commercially available nebulizer device. Key findings: The study’s primary and secondary endpoints of safety and pharmacokinetics were met; Three weekly inhaled doses of AR-501 at 6.4mg, 20mg, and 40mg dose levels were well tolerated in CF patients. No drug related serious adverse events were observed. The majority of treatment emergent adverse events were respiratory in nature and mostly mild to moderate in severity; CF patients achieved high uptake of AR-501 in the respiratory tract, as measured by sputum concentrations, at levels that were more than 50-fold higher than required for inhibition of the target bacteria P. aeruginosa; Inhaled delivery achieved more than 10-fold higher respiratory uptake of gallium than past clinical studies of intravenous gallium which resulted in lung function improvement and P. aeruginosa reduction. The study was primarily designed as a safety and PK trial in clinically stable cystic fibrosis subjects and due to the heterogeneity of concurrent medicine use in the study subjects, exploratory objectives, such as microbiological burden of P. aeruginosa and lung function, were not established in this study.