The new drug Kalydeco is effective for the so-called Celtic gene mutation that impacts CF sufferers in this country.
However, the National Centre for Pharmacoeconomics (NCPE) has recommended against funding of the drug.
The hold-up is understood to be cost related with the medication costing close to $300,000 (€224,500) a year for one patient.
Talks between the HSE and Vertex Pharmaceuticals, the company that produces the medicine, are taking place today with hopes that a new deal can be reached and a rollout of the drug will get full approval,.
The NCPE investigates the budget impact of individual drugs on the Irish healthcare system.
A new drug must first be deemed cost-effective by the centre before it can be added to HSE schemes and made available to patients.
Patients with CF have urged the HSE to conclude these negotiations and make the drug available as soon as possible.
The drug will treat about 11pc of the CF population in Ireland -- approximately 120 people.
And the knock-on effects for all CF sufferers in Ireland could be significant.
This is the first "phase" of the drug and within the next year or year-and-a-half it is expected the next phase will be able to treat most kinds of CF.
Kalydeco has already been approved by the drug regulators in the US and Europe, but Irish health regulators have yet to give it the full green light.
Katie Murphy (23), from Mullingar, is desperately waiting on approval of the drug.
She is one of those who could benefit from the drug and a friend of hers has reported extremely positive results from taking part in the clinical trials.
"I know someone who is on the trial. Ever since he started on the drug, he is a new man," she said. "His lung function has sky-rocketed and he is in a very healthy state. He hasn't had a single chest infection, no oral antibiotics, he hasn't been admitted to hospital and his weight has gone up to a healthy level."
"Most of all he says that his energy levels have greatly improved, he says he has so much energy."
Katie said that she has been hospitalised twice in the past 12 months and has been on antibiotics four times. "I would hope it would benefit me by keeping me out of hospital," she said.
"It is not a cure but it helps to control the symptoms.
"You would still be doing nebulisers and getting treatments like physiotherapy but it would all be a lot easier."
Katie, who now lives in Limerick, said that the panel needs to look at the balance.
"I think there are lots of things that need to be taken into consideration -- there would not be so many requiring hospitalisation, they could enter the workforce and then be taken off disability," she said.
CF patient Jillian Nulty (36) has been in hospital for the last two months but says that the NCPE and HSE panel should not "deny myself and other CFs in this country an improved quality of life.
"If it doesn't get approval now, there is no hope of getting it for the rest of the CF population," Jillian said."
"The next phase could change the lives of the most common gene Delta-F508. But there is a price tag on our lives."