"If you are not going to fund it, how many deaths are okay? Is it okay if 50 people die that could have been saved? Is it okay for 100 to die?
"Speaking individually I think it's bad if one person dies ... These drugs do save people."
Read more: 'I'd be dead by now'
Mrs Renwick has now become a face of the campaign for state funding of Keytruda and has created a petition which she will present to Parliament next year. She has more than 500 signatures from Tauranga alone.
"It's not just about me, I have realised there are all these people suffering and trying to raise money, doing their Givealittle campaigns. We need to be all working together."
Waihi Beach resident Linda Ashly was diagnosed with melanoma in her eye in April, 2014. She went to the optometrist to have an eye check.
"She found a tumour, I'm in perfect health, I'm not obese. I'm fit for a 63-year-old. I live a healthy lifestyle and grow my own vegetables."
But by the time the tumour was found, it was too large to treat so her eye was removed. The melanoma has now spread to her liver.
She could not afford drugs like Keytruda so she started alternative therapies in September.
"It [Keytruda] is $300,000. The average person can't afford that."
Mrs Ashly said Pharmac not funding Keytruda was a political decision.
Minister of Health Jonathan Coleman said he sympathised with melanoma patients.
"Pharmac naturally want to be assured the expensive new treatment, Keytruda, will be effective. Pharmac are working with the pharmaceutical company on data availability to make a better-informed decision. Pharmac are willing to consider how the company can develop the evidence base, and set a more appropriate price given the current evidence base.
"Keytruda clinical trials have examined eight months' worth of data. For one in three patients there was a clear benefit, but not for the remaining two-thirds. This demonstrates more data is required.
"This government has increased Pharmac funding by $150 million over the last seven years, it now stands at a record $800 million per year."