Meanwhile, patients are going into debt to pay tens of thousands of dollars for the drug Cetuximab, which can extend their lives by months or even years.
Maddie Thomas is one of them. She went to the doctor in July 2018 with what she thought was a stomach-ache and ended up with a diagnosis of terminal bowel cancer and a prognosis of six months to live. She was 51.
She had two years' chemotherapy through the public system - but by June this year, her body couldn't take any more.
She couldn't eat, vomited constantly and developed an irregular heartbeat.
An oncologist suggested paying privately for immunotherapy drug Cetuximab, which targets her particular type of cancer.
Thomas ruled that out earlier because she didn't want to leave her family in debt after her death.
But with five children and seven grandchildren, she had everything to live for.
"When someone sort of says to you there's an option and you've got no other option, you've just got to find the money. And we've just had to find the money, so we did - we borrowed money off our house, so we've had to use our mortgage. We were mortgage free and we've had to go into debt for me to have some treatment."
She's had eight treatments and describes the results as phenomenal, with blood results showing her blood cancer marker had drastically reduced.
"In June I was facing being dead. I cannot believe people are not being given this drug."
Now she's spent $60,000, the pharmaceutical company will give her the drug free for a year - but she and her husband will have to find $3500 a fortnight to pay for it to be administered in a private hospital.
Auckland-based gastrointestinal cancer specialist Dragan Damianovich said he's seen Cetuximab extend some patients' lives by five years.
He said it was "heartbreaking" as many patients can't afford it.
Three thousand New Zealanders a year are diagnosed with bowel cancer, which kills as many people as breast and prostate cancers combined.
Damianovich said Pharmac hasn't funded any new bowel cancer drugs in 20 years.
The agency's cancer treatment expert advisory group has recommended funding Cetuximab, which could be effective in up to 40 percent of bowel cancers.
But its main oversight committee disagreed with the evidence and said late last year the medicine should be declined.
"This is an example of where you've got the expert committee saying one thing, and the general oversight committee saying another. And we don't have a process to resolve that level of dispute."
Jackson suggested Pharmac should adopt something like Britain's independent assessment programme to rate clinical benefits in a transparent way.
"This all just feels like groundhog day for me. We've had this discussion with Herceptin, with Keytruda for melanoma ... for a variety of breast cancer drugs over the years, for diabetes drugs more recently.
"And this is part of a broader problem which is the funding of drugs in New Zealand is falling behind that of other countries."
Politicians claim to leave drug-funding decisions to the experts - but that's a cop out in Jackson's opinion.
"The people who are responsible for the increasing gap between medicines in New Zealand and medicines in Australia are not Pharmac - they're doing the best they can with the budget they've got - the people who set the budget and set the rules for Pharmac are the ones that are responsible and that is fundamentally political."
Thomas said the government can't afford to ignore bowel cancer.
"A couple of weeks back Jacinda Ardern came out and said no one in New Zealand should have to rely on their family to buy a home, and yet she doesn't mind people in New Zealand relying on their family to have to stay alive. You know, there's just an inequity in what she said that's not right."
Pharmac declined an interview.
In a written statement, its chief executive Sarah Fitt said Pharmac considered recommendations from different clinical advisory groups in parallel when making its assessments "within its available funding". She said its job was to look at all the evidence and make a decision in the interests of all New Zealanders.
The government has announced an independent inquiry into Pharmac, with Health Minister Andrew Little set to reveal details early next year.
