Parents of children with the condition flew 7,300 miles to buy a "life-saving" drug unavailable on the NHS in England.
A Cumbrian father says he's now more hopeful that his daughter will eventually have access to a drug that could prolong her life, and ease her symptoms.
Ayda Louden, from Carlisle, has cystic fibrosis, and her father David Louden says she needs a drug called orkambi, but it's not widely available on the NHS because it's considered too expensive.
A Parliamentary debate on the subject was held yesterday, David was there, and he says he is more optimistic than he has been for a while that negotiations to allow the drug's use are making progress.
We are the closest that we've ever been, there have been multiple meetings, we can't get much information at the moment but we know the meetings have taken place."
A West Midlands MP has called on the government to do more to allow people with cystic fibrosis to get access to the "life-changing" drug, Orkambi.
It has been licensed in the UK since 2015, but is not widely available on the NHS because of a dispute over cost with the US manufacturer, Vertex.
Speaking in a special Commons debate, independent MP Ian Austin pointed to the example of Carly Jeavons of Dudley, who'd participated in a clinical trial in 2014.
He told MPs that before the trial she was taking 90 tablets every day, but still only had less than half a normal lung capacity.
But, he added that Ms Jeavons said "Orkambi has changed my life", with her health remaining stable and hospital visits reduced.
The family of Harriet Corr join thousands pleading for access to cystic fibrosis drug Orkambi.
Orkambi is a drug that targets a mutation that around 50% of people with cystic fibrosis in the UK have.