Pharmac has been accused of being unable to cope with breakthrough cancer drugs after it declined to immediately fund a treatment for melanoma.
The Government's drug-buying agency says Keytruda, or pembrolizumab, is as yet unproven and too expensive to fund and has been designated low priority.
It was registered by Medsafe in September for the treatment of the most deadly form of skin cancer, advanced metastatic melanoma.
The drug, now approved for use in 30 countries, is a first line immunotherapy treatment that uses the body's own immune system to detect and destroy the melanoma.
However, the $170,000-a-year treatment is still beyond the reach of most patients. Funding it could cost Pharmac $30 million a year.
Melanoma New Zealand has said most of the 340 New Zealanders who die each year from melanoma could benefit from it.
Cancer Society medical director Chris Jackson says Keytruda is already being funded in the US, UK and Australia, and New Zealand is well behind them in terms of access to new drugs.
"Pharmac seem to be saying that chemotherapy is the best treatment for patients with advanced melanoma - and that is very hard to understand."
Three previous melanoma treatments have also been declined, which highlighted a weakness in Pharmac's system, Dr Jackson said.
"Pharmac's system doesn't cope with these breakthrough cancer drugs that have early but compelling data.
"Melanoma is a disease with huge unmet need, and so patients, families, and oncologists around the country are going to be bitterly disappointed with this decision."
Yesterday, Pharmac said data was not conclusive.
The data showed most people receiving pembrolizumab for malignant melanoma would not see a response in their tumours. It was also not clear whether it helped people live longer.
"Our expert advisers recommend pembrolizumab as an option for funding, but not ahead of other medicine funding options that offer a better balance of evidence and price."