However, the panel recently rejected his application again. Mr Maxwell said: "They feel it's not making a considerable benefit to my quality of life versus the cost."
"I've found that hard to accept, because in my position, six to nine months is invaluable.
"There's no cost you can put on that, to have six or nine months with my family."
Mr Maxwell said some private donors had offered help, but he planned to go through the appeals process to overturn the decision.
"The IPFR panel exists to support patients like me in Wales," he added.
Mr Maxwell has raised more than £1.6m to support the cancer pathway in Wales with his latest challenge, a 72-mile (115km) row from Tenby to Cardiff, taking place only a few weeks ago.
"We feel desperately strongly about supporting cancer pathway in Wales, regardless of what the funding decision is," he added.
Mx Maxwell said, despite the cost of the drug, he did not understand the reason for the panel's rejection.
"I understand the drug is very expensive," he said.
"But is the best thing for me at the moment and it was recommended to me by multiple professionals."
Mr Maxwell said he didnot think there is a crisis in cancer care for Welsh patients.
But added that there "needs to be more" investment in the cancer pathway.
"It's made me realise how important fundraising is, not just for me, but for future patients."
Mr Maxwell said his family are trying to enjoy and laugh together recognising that "staying close is important".
"There have been some amazing moments and experiences throughout this journey and I have to savour them," he said.
Cardiff and Vale University Health Board said it had "worked extensively" with Mr Maxwell to raise awareness of his condition.
"We are unable to comment further on individual patient cases," the health board added.
