Pharmac has agreed to fund a nine-week course of Herceptin combined with a taxane drug for women with early HER2-positive breast cancer.
The decision comes after a period of consultation and after a group of women campaigning for a full-year course of the drug said they would seek a judicial review of how Pharmac decided on funding for the drug.
A joint statement from Pharmac and district health boards yesterday said 350 women each year would benefit from the Herceptin funding decision.
The funding, available from July 1, represents an investment of $6 million a year by health boards.
Pharmac deputy medical director Dilky Rasiah said the decision was a positive step for the treatment of the HER2-positive strain in New Zealand.
"This way of using Herceptin has been shown to reduce the chances of breast cancer tumours returning as effectively as any of the longer-treatment duration studies."
The shorter treatment was cost-effective and affordable for district health boards, Dr Rasiah said.
Pharmac's criteria for decision-making included cost relative to clinical benefit and risks, total cost, the impact on health boards' resources and Government health funding priorities.
Funding for 12 months of treatment could not be justified under those criteria.
Dr Belinda Scott, chairwoman of the Breast Cancer Foundation's medical committee, said scientific data overwhelmingly supported one year of therapy, and that was the foundation's preferred option.
But a nine-week course of Herceptin was better than nothing.
"However, we hope Pharmac ensures women are made fully aware of the limited scientific basis of this decision.
"Right now, we know from international trials involving thousands of patients that Herceptin gets very good results taken over 12 months.
"There needs to be proper double-blind, randomised drugs trials comparing 12 months with a shorter six months treatment before we accept a nine-week course is adequate. In a perfect world breakthrough drugs like Herceptin would not cost so much, and drug budgets would be big enough to accommodate all those in need.
"But when using scarce public health resources, it's best to stick to what is known at any one time."