World-First Cancer Vaccine Trial Shows Promising Results in Reducing Melanoma Recurrence

A groundbreaking clinical trial has shown that a personalized mRNA cancer vaccine can significantly reduce the risk of melanoma recurring or patients dying from the disease. The vaccine, known as intisemran, targets unique genetic mutations in cancer cells to train the immune system to fight the tumor.

In findings led by Professor Georgina Long of the University of Sydney and Melanoma Institute Australia, the vaccine cut the risk of cancer recurrence or death by 42% compared to standard treatment with the immunotherapy drug pembrolizumab (Keytruda). This marks a potential paradigm shift in how certain cancers are treated.

"These results show that patients with earlier-stage melanoma can be treated after surgery in a fundamentally new way," Professor Long stated. "These results are more than a landmark for melanoma. Just as email transformed how we communicate, individualised neoantigen therapy has the potential to transform how we treat cancer."

The intisemran vaccine is developed by Moderna and MSD and is tailored to each patient's tumor based on its specific genetic characteristics. It targets abnormal proteins, or neoantigens, that arise from mutations in cancer cells, prompting the immune system to identify and attack them.

The international trial, funded by Merck and Moderna, involved 1,137 patients whose melanoma had been surgically removed but who were at high risk of recurrence. The study was conducted across 157 sites globally, including several in Australia.

Professor Long, who was recognized as Australian of the Year in 2024, described the approach as a significant advancement, combining personalized medicine with mRNA technology and sophisticated data analysis. "This is a coalescence of an mRNA platform, personalised, and the use of algorithms and data in a way that we've never seen before," she said.

Associate Professor Seth Cheetham, director of the Australian mRNA Cancer Vaccine Hub, called the findings a major breakthrough. "This is the first really large trial that's shown definitively that this technology works, it reduces the risk of recurrence or spread and results in better outcomes compared to standard of care," he noted. "This is really the gold standard, and it's what the entire field's been waiting on."

While the current trial focused on melanoma, Professor Long suggested the implications could extend to other cancers. "Track record predicts future," she said. "So advances in melanoma transformed lung cancer, kidney cancer, head and neck cancer, bladder cancer, so many other cancers."

News of the trial's promising results reportedly caused Moderna's shares to surge significantly in a single trading day in August.