As someone with CF, I remember hearing about gene therapy as a kid as far back as the late 80s. Thankfully, we didn’t have to wait for it for many CF patients to have their respiratory issues much improved or even resolved with CFTR modulators.
https://www.cff.org/managing-cf/cftr-modulator-therapies
Last I heard, they are life changing for some people with CF. On the downside, they are typically extremely expensive (like $250k annually) and have to be taken for life and don't work for everyone. It depends on your specific CFTR defect, the CFTR being the defective cell channel at the root of all CF symptoms and pathology.
Medication for those interested. https://www.trikafta.com