Personalised mRNA vaccine cuts melanoma recurrence risk by 42% in trial
Australian-led phase III trial finds intismeran plus pembrolizumab lowered melanoma recurrence or death risk by 42% versus immunotherapy alone at two years.
The story in focus
An Australian-led phase III trial of 1,137 patients with surgically removed melanoma found that the personalised mRNA vaccine intismeran combined with pembrolizumab reduced the risk of recurrence or death by 42% at two years compared with pembrolizumab alone, The Guardian reports. The vaccine is not yet approved as standard treatment.
- Intismeran plus pembrolizumab cut recurrence or death risk by 42% versus pembrolizumab alone at two years
- 82% of combination recipients were alive and recurrence-free, compared with 70% on immunotherapy alone
- The trial enrolled 1,137 patients whose melanoma had been surgically removed but who were at high risk of return
- Results are being presented at the ESMO congress in Madrid and accepted by the New England Journal of Medicine pending peer review
- The vaccine is not yet available as standard treatment and may take several years to clear regulatory review
What the trial found
The Australian-led phase III trial included 1,137 patients whose melanoma had been surgically removed but who remained at high risk of recurrence. All received pembrolizumab for twelve months; some also received intismeran, a vaccine custom-made to target genetic mutations unique to each patient's tumour.
At two years, the combination reduced the risk of melanoma recurrence or death by 42% compared with pembrolizumab alone. Among those given both treatments, 82% were alive and recurrence-free, against 70% of those on immunotherapy alone. The Guardian reports that it is the first individualised cancer vaccine to show positive phase III results.
Caveats and next steps
Prof Georgina Long of the Melanoma Institute Australia described the findings as a foundational shift in cancer treatment. She is presenting them at the European Society for Medical Oncology's annual congress in Madrid. The results have been accepted for publication in the New England Journal of Medicine and will need to go through peer review.
Dr Jessamy Tiffen of the Centenary Institute, who was not involved in the research, noted that a significant portion of patients do not respond to the vaccine initially, and that only time will tell how effective it is beyond two years. The drug manufacturers said the data were insufficient to show whether the combination improved long-term survival. The vaccine will not be standard treatment until further study and regulatory review, which may take several years.
How many patients took part in the melanoma vaccine trial and how were they treated?
The trial enrolled 1,137 patients whose melanoma had been surgically removed but who were at high risk of recurrence. All received pembrolizumab for twelve months, and some also received the personalised intismeran vaccine.
Sources & further reading
- ‘Bespoke’ mRNA vaccine significantly reduces risk of melanoma recurrence or death, clinical trial shows ↗The Guardian
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