A personalised vaccine given alongside immunotherapy reduced the risk of melanoma returning or death by 42% compared with immunotherapy and a placebo, the BBC reports. The trial involved 1,137 adults who had undergone surgery to remove their tumours. The findings are promising, but the vaccine remains experimental, and longer follow-up is needed to assess its effect on overall survival.
All participants received Keytruda, an immunotherapy drug. Around two-thirds also received the experimental vaccine, Intismeran, while the others received a placebo. That distinction matters: the results concern adding the vaccine to immunotherapy, not using it on its own.
According to the BBC report, the combination also reduced the risk of melanoma spreading by 38% over two years. A team at Addenbrooke’s Hospital in Cambridge, including oncologist Professor Pippa Corrie, took part in the research.
A vaccine tailored to each patient’s tumour
Intismeran uses mRNA technology and information from an individual patient’s tumour to direct the immune response against cancer cells. It is therefore a treatment developed for each patient, rather than a preventive vaccine given to healthy people to stop them developing the disease.
The reported 42% reduction refers to the combined risk of two outcomes: the cancer returning or death. It does not mean the vaccine prevented every recurrence, or that the risk fell by 42 percentage points. The BBC does not give the absolute rates of these events, so its report cannot establish how many additional patients avoided recurrence or death as a result of receiving the vaccine.
Promising results, but not yet routine treatment
Professor Alan Melcher of the Institute of Cancer Research in London, who was not involved in the trial, described the findings as very promising. However, he also highlighted the need for longer follow-up. The trial is due to continue so that researchers can better assess the long-term effects, including the treatment’s impact on overall survival.
For patients in the UK, a key question remains whether the treatment will become available. Discussions between the manufacturers and regulators do not amount to approval or establish a timetable for access. According to the BBC, wider use in the NHS, the UK’s publicly funded health service, will also depend on the costs of analysing individual tumours and manufacturing the vaccine.
The manufacturers, MSD and Moderna, also report research into this approach in other cancers, including kidney, bladder and lung cancer. The result in melanoma patients does not, however, demonstrate that the treatment works in those diseases: each requires a separate assessment.
