Time is precious for single dad Daniel Webby, who has an extremely rare blood disease.

The disease could be treated. The trouble is the drug isn't funded.

Mr Webby is one of eight New Zealanders appealing to Pharmac to subsidise a life-saving treatment that is funded in 40 other countries, including Australia.

The disease is called paroxysmal nocturnal haemoglobinuria (PNH), which causes the destruction of red blood cells. About 20 Kiwis have it.

If left untreated, its long-term effects can be painful and potentially life-threatening. It's estimated that one in three people will die within five years of diagnosis.

Mr Webby, 32, is spearheading a campaign to pressure the Government's drug-buying agency into negotiating a deal with manufacturer Alexion Pharmaceuticals.

The Auckland artist was diagnosed with PNH in 2011 after suffering chronic fatigue for several years.

"I've noticed over the last 12 months it's just got harder and harder to cope, to keep up," he said.

"What's really frustrating is there's the treatment just sitting on the shelf that's not available to me that would restore my quality of life and give patients a longer life expectancy."

The medication is called Soliris and it is expensive - Mr Webby gave a ballpark figure of about A$400,000 (NZ$0.5 million) a year for each patient.

The drug was approved by Medsafe for use in New Zealand at the end of 2011, but has not yet cleared the Pharmac funding hurdle.

Pharmac medical director Peter Moodie said the application, made by Alexion, was being assessed through the usual processes.

The Pharmacology and Therapeutics Advisory Committee last year declined the application for Soliris, also called eculizumab, as it was not impressed with the quality of clinical evidence. The application was referred to the haematology subcommittee, and the advisory committee is due to hear back from the subcommittee next month.

These committees provide recommendations to Pharmac, which then makes the final decision.

Hamilton haematologist Humphrey Pullon, who is backing the campaign, said Pharmac's failure to fund the drug was "becoming a public scandal".

"It transforms patients' lives. It improves their sense of wellbeing and ultimately prolongs survival."

Mr Webby confirmed the communications company behind the campaign was being funded by Alexion, however, the local PNH Support Association was organising the campaign.

''Our motivation is for patients' health.''

WHAT IS PNH?

The destruction of red blood cells, known as haemolysis, is the main cause of serious health problems in PNH sufferers.

Serious and potentially life-threatening effects include deadly blood clots and kidney failure.

Patients with PNH also suffer from severe fatigue, abdominal pain, difficulty swallowing, erectile dysfunction, and poor cognitive function.

The drug Soliris works by preventing haemolysis.

- © Fairfax NZ News