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.
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.
I have dropped all medical treatments except for pancreatic enzymes due to these. My pulmonary function tests came back as 104 after over a year of dropping the primary treatments for this being albuteral, "vest", and sinus surgeries. If you qualify for this medication it's life changing.
They are also brand new. For the drug as well the company is actual very helpful and realistically after insurance and the companies assistance I have paid 2, $15 co-pays the last 2 years.