Personalised melanoma vaccine cuts recurrence risk in late-stage trial

A personalised melanoma vaccine called intismeran reduced the reported two-year risk of cancer returning or death by 42% when added to pembrolizumab in an Australian-led trial of 1,137 patients, The Guardian reported on 23 October. The result offers a potential new way to treat people whose melanoma has been surgically removed but remains at high risk of returning.

The trial compared the combination with pembrolizumab, an immunotherapy drug also sold as Keytruda, plus a placebo. NBC News reported that 757 patients received the vaccine and 380 received the placebo. At two years, 82% of those given the combination had not had a recurrence, compared with 70% of the placebo group. The 42% figure describes a reduction in relative risk; the 82% and 70% figures show the proportion without a recurrence in each group.

How the personalised melanoma vaccine works

The BBC and the Evening Standard also reported a 38% reduction over two years in the risk of melanoma spreading or death with the combination treatment. That is a separate measure from the risk of recurrence or death. The reported results concern patients at high risk after their tumours were removed; they do not establish how the vaccine would work for people with visible cancer or for those who do not respond to pembrolizumab.

What the trial means for patients

Professor Georgina Long, medical director of Melanoma Institute Australia, called the findings ‘a foundational shift in our approach to cancer’, The Guardian reported. She said the approach could harness the immune system more personally to reduce the risk of recurrence or death. The manufacturers said it was too early to tell whether the combination improves long-term survival, and the BBC reported that independent cancer experts want longer follow-up to establish whether patients live longer on average.

The full results were due to be presented at the European Society for Medical Oncology meeting in Madrid on Saturday, 24 October, the BBC reported. They had not yet been published in a peer-reviewed medical journal. The Guardian reported that intismeran would need further study and regulatory review before it could become a standard melanoma treatment, a process that may take several years.