Tom McNamara thinks he was about eight when he was sunburned. “In my younger days my mother would take us to Bronte Beach to see the family. It’s taken all these years for my melanoma to show up.”Now 75, the former radiographer at Royal Prince Alfred Hospital in Sydney was told last year he had secondary cancer in his lung, with another tumour on his liver. In Australia, 30 people a day are diagnosed with melanoma, and 1,200 die each year.“Basically I was devastated. Having been a radiographer, I knew what to expect. If you have secondary cancers in your liver, I would think you would normally have about four months to live.”Mr McNamara, however, was one of 19 patients with advanced melanoma at Chris O’Brien Lifehouse and Royal Prince Alfred Hospital to participate in the global trial of a new drug, pembrolizumab (Keytruda).Pembrolizumab works by targeting a protein on the surface of immune cells that stops them from attacking the melanoma cells, preventing the PD-1 protein from stopping the immune response against the melanoma. For some, the drug prolongs survival and is also less toxic than alternatives, producing fewer side effects.The global study compared pembrolizumab with another immunotherapy drug, ipilimumab and found that pembrolizumab “prolonged progression-free survival and overall survival and had a favourable safety profile compared with ipilimumab in patients with advanced melanoma”.Dr Catriona McNeil, who treats Mr McNamara at Chris O’Brien Lifehouse, a cancer hospital serving patients from Royal Prince Alfred Hospital and around Australia, says: “I would regard these outcomes as some of the most game-changing that I’ve seen in my career. It’s tremendously exciting for all of us working in cancer medicine.”More than a year later, Tom is not only still alive, his tumours are shrinking. A 10cm tumour on his lung has shrunk to around 2cms.“I have worked in a hospital all my life. I know the value of having someone for testing. I was prepared to be in the control group, and I knew that it could either save my life or I would die. This wasn’t about grasping at straws to stay alive – by doing this, I was able to do something much bigger for other people as well.Tom is back looking after his flowers. “I have a big garden with roses and plenty of chrysanthemums.”Some of those roses go to Dr McNeil, every time he visits her for his ongoing treatment.