Media playback is unsupported on your device Media caption Cystic fibrosis means gruelling sessions of physiotherapy every day for three-year-old Ivy

"I don't want to bury my daughter - but that's the reality of cystic fibrosis."

Kimberly Roberts is the mum of three-year-old Ivy, who has cystic fibrosis - or CF - which is a genetic lung disease with no cure.

Along with her friend Alison Fare, who has two daughters with the condition, they want access to one of the most advanced treatments - the drug Orkambi.

But the manufacturer and NHS bosses have been locked in arguments over its £100,000-a-year price tag since 2015.

"Our children deserve to have it - deserve to live a healthy long life. Without that drug they won't have one," said Mrs Roberts, who lives near Conwy in north Wales.

Nice - the body which recommends whether a drug or treatment is available on the NHS - has said that the ongoing bills for the drug would be "considerably higher than what is normally considered a cost-effective use of NHS resources".

Like many in the CF community, the two friends have been campaigning hard for access to the drug Orkambi to help control the condition.

"We just want the medicines for our kids," said Mrs Fare, who is also from Conwy.

Both her daughters, six-year-old Imogen and three-year-old Annabelle, have CF.

She would love the chance for her girls, especially Annabelle, to be able to play with Ivy - but the risk of cross-infection means that can never happen.

Image caption Mothers Alison Fare, left, and Kimberly Roberts are campaigning for access to the cystic fibrosis drug Orkambi

"It's not great, because me and Kim are friends, so it would be nice - even just to go out to take them playing, to a playground or whatever," said the girls' mother.

"But we can't risk it - just in case they pass anything to each other."

The fear of infection dominates the lives of the two mothers, as they know it can lead to lengthy stays in hospital - or worse.

"It's very unpredictable and that's what's scary for us," said Ivy's mother.

"One day they can be absolutely fine, and it only takes them to pick-up the wrong bug or an infection from somebody else, and that can lead to long term lung damage, which is irreversible."

Cystic Fibrosis

Image copyright Getty Images Image caption A build-up of mucus in the chest can lead to infections for those with CF

Cystic fibrosis is an inherited condition in which the lungs and digestive system can become clogged with thick, sticky mucus

It can cause problems with breathing and digestion from a young age.

Some of the main symptoms of cystic fibrosis can include recurring chest infections, difficulty putting on weight and frequent, wet-sounding coughs

There's currently no cure for cystic fibrosis, but a number of treatments are available to help control the symptoms

The condition can be fatal if it leads to a serious infection or the lungs stop working properly

It is the battle to maintain lung function - the simple task of breathing - that makes Vertex's drug so important for campaigners.

According to the American manufacturers, Orkambi can slow down the loss of lung function in CF patients by over 40% - and is suitable for use with the most common form of the disease - the variant that Ivy, Imogen and Annabelle all have.

But while the drug was approved by the EU in November 2015, no health service in the UK can routinely prescribe it.

Cost

Nice has said the cost for the drug would be "considerably higher than what is normally considered a cost-effective use of NHS resources".

In July, NHS England made an offer of £500m for five years to have the treatment, with £1bn over 10 years.

But while that offer remains on the table - the deal has not been done.

Image caption Orkambi has been hailed as life-changing - but at a price

In Wales, the Welsh Government said it was guided by the Nice recommendation, along with the views of the All Wales Medicines Strategy Group (AWMSG).

Officials from the Welsh Government said its medicines group was willing to review its position - but claimed the ball was in the drug company's court.

"We are still waiting for Vertex to submit a reappraisal including the new clinical data they say is now available," said a Welsh Government health spokesman.

"It is frustrating that Vertex refuses to engage in any meaningful way with the established and well-respected appraisal processes in Wales."

Vertex has insisted it is ready and willing to talk.

"We are keen to get back round the table as quickly as possible to resume discussions with NHS Wales All Wales Medicines Procurement," one of the company's UK representatives said.

"We submitted a portfolio proposal to All Wales Medicines Procurement on 12 July and stand ready to discuss this proposal in detail with NHS Wales, the Welsh Government and other key stakeholders to find a solution for cystic fibrosis patients."

Image caption Ivy uses a nebuliser as part of her treatment

But the parents of the three Conwy girls said they were "angry and frustrated" by the ongoing delays in accessing treatment.

"We've got an impasse at the moment between the drug company Vertex and the NHS," said Mrs Fare.

"One needs to lower its prices, the other needs to step-up the offer they've given and meet somewhere in the middle, because at the moment it's not going anywhere."

Both mothers said their message was clear to all involved: "Just get the deal done. Get round the table, talk, and don't leave the room until you've done the deal."

Ivy's mother is frustrated at the uncertainty.

"We don't want to outlive our children," said Mrs Roberts. "That's the fear we live with daily.

"This is due to greed on Vertex's behalf and the NHS not moving. Something needs to give, because while we are waiting for this drug, people are losing their lives."