"There's no evidence of the disease," she tells the Bay of Plenty Times.
"The immunotherapy drugs are still working really well for me."
Renwick, 48, was diagnosed with advanced melanoma in May last year and given just weeks to live.
A mother of three adult children, she immediately began a course of gene therapy drug Dabrafenib, and after five months switched to immunotherapy medication Keytruda.
The treatments saved her life but came at a cost of more than $10,000 a month, paid for by Renwick and her family.
The experience propelled the Mount Maunganui College maths teacher into the national spotlight as she began a battle to secure access to Keytruda for everyone with the disease.
On March 1, she presented a petition to Parliament calling on government drug-buying agency Pharmac to fund Keytruda.
The petition was signed by 11,000 people and in May, Pharmac announced it would fund Keytruda rival Opdivo. In July it extended the funding to Keytruda.
Renwick has since been nominated for the New Zealand Herald People's Choice Award for New Zealander of the Year.
The winner will be announced on New Year's Eve and she says she feels flattered to be nominated.
"I was really surprised and quite honoured but I feel it's not a nomination for me. I feel like I've been nominated on behalf of all the people with melanoma who spoke out."
Renwick says although she became the face of the Keytruda campaign, she did not act alone.
She was flanked by other melanoma sufferers when she presented the petition to Parliament and says it was a joint effort.
"It would never have succeeded were it not for all the other people who also stood up and made themselves heard and also the regular, everyday New Zealanders who signed the petition and who offered their support."
She was spurred to start the petition, she says, after regularly seeing stories in the news of individuals trying desperately to raise money to save members of their families with melanoma.
"I just thought there's no strength in standing alone. We all have to stand together."
Renwick's first clear scan came more than a year ago, and she continues to have three-monthly checks.
"Every scan is still a little scary. I think it always will be, but at the moment everything's going well. I'm back to normal ... I'm just trying to get back in to living life, being healthy, enjoying things."
She remains on Keytruda, the difference being that it is now funded by Pharmac and she can get the treatment locally.
"I go to Tauranga Hospital. Previously I was having to travel to Auckland every three weeks."
She says Keytruda is working "because if it wasn't working I'd be sick again by now".
The medication is expected to save 120 lives a year, but it is uncertain how long Renwick and other patients will need to take it because it is such a new drug.
"In theory, once your immune system learns to recognise and destroy the cancer cells, it should be an ongoing thing. But of course, these are new days so they're only just really working it out as they go along."