"It's a mixture of joy and sorrow. It's wonderful that people now have a choice and treatment and hope. But that's also tinged with sadness, because of the people who have died along the way."
Three-hundred-and-fifty people die of melanoma in New Zealand each year, and some of those lost in the last year would have benefited from access to Keytruda, Renwick said.
Fellow Keytruda campaigner and melanoma sufferer Katrina Govorko said Pharmac's decision gave those with melanoma choice.
Govorko, who was diagnosed with melanoma in March 2014, said it had been a big battle to win funding for Keytruda. She started an online petition to campaign for Keytruda funding.
"I'm very excited. This gives us some choice."
The 49-year-old Auckland mum was on a different drug combination - dabrafenib and trametinib. Those drugs are not funded but she was one of the last people to be given the drug on compassionate grounds. She would stick with the treatment as it was working for now.
But they had a shelf life, sometimes of less than a year, and Keytruda could be the next step, she said.
"[Pharmac's decision] gives me an option. When you run out of options it becomes quite scary. It's nice to know I have that option without having to worry about fundraising.
"Unfortunately some people who need it before now have not been able to access it and it's been a sad journey for them."
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had cited a lack of evidence about Keytruda's efficacy, and said evidence presented by maker Merck Sharp & Dohme had not been peer-reviewed.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.