A woman fighting cancer for the third time - and who was told she may only have two months to live - hopes to get more time with her husband after learning she is getting six months of treatment.

When Mon Macdonald was diagnosed with blood cancer two months ago doctors said the disease was terminal and her only treatment option was a drug called Vidaza.

Without it she was given a prognosis of six to eight weeks.

It was too risky for her to have chemotherapy because of her exposure to it while battling breast and ovarian cancer in 2010 and 2016.

A Pharmac spokesman said the organisation was unable to comment on indivdual applications - including Macdonald's - but its website states Pharmac funds Vidaza for some blood cancer patients. Decisions are made on a case-by-case basis.

Macdonald's haemotologist put in an application for six monthly "cycles" of the drug and on December 21 phoned Macdonald to tell her it had been approved.

She started treatment the next day for her cancer, acute myeloid leukaemia .

"I'm just so happy that we finally have some good news on the medical side of things because everytime we go and see a doctor since the 6th of November it's just getting worse and worse and worse," Macdonald told the Herald on Sunday.

"[I've] got time to tidy up. Maybe do a little bit more travel."

Her husband Gabe said the approval was a perfect Christmas present that came as "huge relief".

"It's amazing. Obviously we don't know if [Vidaza's] going to work fully. But we're just incredibly grateful. We didn't know how we were going to get through financially, health-wise. Hope's always lovely, just for our mental state."

The couple had been fundraising to pay for it themselves in case their application was declined and Gabe estimated six months of Vidaza would cost about $72,000.

"There's no way we can afford that even with fundraising," he said.

Macdonald previously told the Herald on Sunday late last year she hoped to live until at least her 40th birthday, but last week, said said the couple were now focusing on getting through the next six months.

She and Gabe both returned to work on Monday after the Christmas and New Year holidays - a week of which Macdonald spent in hospital for her first cycle of Vidaza.

Although the treatment had left her feeling a bit nauseous and tired, it was "easy" compared to chemotherapy and radiation.

Macdonald and Gabe would find out how effective Vidaza had been in killing the cancer after she had her second dose in late January.

Gabe said he understood Vidaza could prolong patients' lives by up to three years in some cases, but other people only lived an extra six months.

If Vidaza was still killing Macdonald's cancer at the end of the Pharmac trial, the couple would try to pay for another course themselves.

They also planned to holiday in Queenstown this autumn if Macdonald was well enough.

"We feel like we need a break, but at the moment it's probably not safe for me to go just yet," Macdonald said.

Gabe added he and his wife were trying to keep their lives as normal as possible at the moment.

However, he would stop working to care for her if her health deteriorated, so they could the make the most of their time together.

They would continue to fundraise for treatment and living costs through Give a Little.

"If we go on sickness benefits we just can't survive on that. It's just ridiculous living and renting," he said.

What is Vidaza?

• Vidaza is a brand name of the drug azacitidine which stops cancer sells growing and eventually destroys them

• It can be used to treat acute myeloid leukaemia and other blood cancers and is usually prescribed to patients who are unable to have other treatments for health reasons

• Like chemotherapy and other cancer treatments Vidaza can also affect the growth of normal body cells

• Patients being treated with Vidaza are given injections every day for a week then have a three week break before getting another dose

• Most patients get six monthly "cycles" of Vidaza

• Pharmac funds the drug through "special authority" for blood cancer patients who meet certain criteria - a haemotologist must submit or make the application