Clinically meaningful improvements in ppFEV1 at 12 months observed in 2 of 3 participants with mild to moderate baseline lung function impairment (ppFEV1 50-80%) and >6 months follow up Aerosolized 4D-710 was well tolerated at doses up to 1E15 vg (n=6) Dose-dependent and widespread 4D-710-mediated CFTR transgene RNA and protein expression observed in all lung biopsies from all participants evaluated to date Pre-existing AAV immunity cross-reactive with A101 did not affect transgene expression, biological ac ...