Pharmac has confirmed it will fund the melanoma drug Keytruda.

The drug-buying agency’s director of operations Sarah Fitt said the drug, also known as pembrolizumab, would be funded from September 1.

“Since we first received the funding application for pembrolizumab, new information has emerged that has given PHARMAC the confidence we needed to progress the funding decision.”

As part of the deal, Pharmac will also fund a tablet form of the antifungal agent pasaconazole (Noxafil) from the same date.

Today’s announcement comes after Pharmac in June published a provisional agreement to fund Keytruda.

Pharmac and Health Minister Dr Jonathan Coleman had cited a lack of evidence about Keytruda's efficacy, and said evidence presented by maker Merck Sharp & Dohme had not been peer-reviewed.

After a $39 million boost as part of May's Budget was confirmed, Pharmac proposed to fund rival melanoma drug Opdivo.

It now says patients will be able to switch melanoma drugs within 12 weeks of starting if their first one was intolerable and their disease had not progressed.