Young melanoma patient Jeffrey Paterson helped to win the campaign for Government funding of Keytruda, but didn't benefit from it himself.
Paterson, aged 23, died on Friday evening, his family says.
The Unitec architecture graduate helped deliver the ultimately successful petitions to Parliament in March seeking state funding of Keytruda, a new and extremely expensive medicine that is extending the lives of many patients diagnosed with inoperable, terminal melanoma.
"It is with a heavy heart that we tell you that ... Jeffrey John Paterson slipped away peacefully surrounded by his family, just as he had asked to go," his family said in a statement posted on Facebook.
... the Pharmac model allowed people to die that could have been saved. There was an acceptable level of preventable death and that's a big problem for me.
"He was such a fighter to the end, and we know that he wants us to support each other through this time.
"We are so proud of all of Jeffie's achievements, from his relationships with his friends and family, his long nights studying at university, his skilful guitar and surfing, and his sacrifice for the melanoma community.
"Jeffie's message to us would be to stay strong, and thank everybody that had played even a small part in his life journey."
Keytruda was registered for treating advanced melanoma by Medsafe, the New Zealand medicines regulator, last September and its rival, Opdivo, a very similar drug, was registered in April this year.
State medicines buyer Pharmac began funding Opdivo in July and will do likewise for Keytruda from next Thursday. Keytruda's maker, Merck, Sharp and Dohme, began supplying the drug at no charge in June until the start of state funding.
Some patients were paying around $300,000 for two years' treatment with Keytruda in the private health system before state funding kicked in.
Tauranga high school teacher and mother Leisa Renwick, who started one of the petitions, was expected to die of malignant melanoma last year, but after treatment with dabrafenib and now Keytruda she is well.
She said of Paterson, "I'm privileged to have known him. He was a lovely young man with a really loving family who was willing to speak out and to expose his private pain to the public in the hopes of getting this drug funded.
"It's so sad he never got the chance to have treatment with them himself."
Another melanoma patient, Kathryn Williams, of Upper Hutt, said Paterson was "a truly great New Zealander".
"You leave an indelible mark on the melanoma cancer landscape and you leave an indelible mark in our hearts," she wrote on Facebook.
"Your firm and enduring resolve to fight and secure cancer treatment for melanoma resulted in treatment being made available in New Zealand."
Renwick told the Herald the funding of the new medicines - which did not work for everyone with advanced melanoma - came too late for a number of patients.
"Over the year from Medsafe approval to Pharmac funding [of Keytruda] a lot of people have died and unfortunately they still are because they got too sick for it to work.
"One reason I'm still here is I got the right drugs at the right time. The only reason that happened is because I could pay."
"The broader picture for me ... is that ... the Pharmac model allowed people to die that could have been saved. There was an acceptable level of preventable death and that's a big problem for me. That problem still exists."