A cancer treatment described as a "miracle drug" by many patients has been approved for use in melanoma patients before their cancer spreads and becomes advanced.

Until now, Keytruda had only been approved for use to treat stage four melanoma in New Zealand. By then the cancer is classified as advanced and has usually spread to other parts of the body.

Today, drug company Merck Sharp and Dohme New Zealand announced the immunotherapy drug had also been registered for the treatment of stage three melanoma - melanoma which has been surgically removed but was found in the lymph nodes.

Chief executive of Melanoma New Zealand Andrea Newland welcomed the news.

Advertisement

"This registration offers real hope to patients who previously have had to wait until they had advanced or metastatic melanoma before they could be considered for Keytruda therapy. It recognises the benefit in starting patients earlier before they become stage four.

"New Zealand has the highest melanoma rate in the world so preventing, detecting and treating melanoma early, need to be absolute priorities."

The approval was based on a clinical trial of 29 stage three melanoma patients in New Zealand and found the drug reduced the risk of the cancer recurring by 43 per cent when compared to a placebo after 12 months of treatment.

Merck Sharp and Dohme New Zealand director Paul Smith said it was great news because stage three patients had a 48-85 per cent chance of the cancer becoming stage 4 within five years.

Keytruda now had 10 registrations across five tumour types in New Zealand.

A funding application for stage three melanoma had been lodged with Pharmac, Smith said.

The drug first gained funding for use in advanced melanoma in 2016 after a huge public outcry, led by patient Leisa Renwick, which was sparked because not everyone could come up with the $60,000 to pay for it.

Since then it has prolonged the lives of thousands but now patients with non-small cell lung cancer and Hodgkin lymphoma are pushing for funding also.

Advertisement

"Keytruda has been funded for stage three melanoma patients in at least eight countries," Smith said.

"Given our rates of stage three melanoma, this could significantly benefit patients and reduce metastatic melanoma. We have made a funding application to Pharmac and we are hopeful that New Zealanders with stage III melanoma will be able to benefit from using Keytruda earlier."

Pharmac last year spent $23.5 million on Keytruda for people with advanced melanoma, a spokesperson said.

Its website showed funding was being considered for five other stages and types of cancer.