New Delhi: A personalised cancer vaccine developed by Moderna and Merck has shown promising results in a large clinical trial, reducing the risk of melanoma recurrence or death by 42 per cent when combined with an existing immunotherapy drug. The findings mark a significant step forward for personalised cancer treatment, although further research, peer review, and regulatory review are needed before the vaccine can become widely available.
Melanoma is the most dangerous form of skin cancer and can return even after surgical removal, particularly in patients at high risk of recurrence. The experimental vaccine, which uses messenger RNA (mRNA) technology similar to that employed in some Covid-19 vaccines, is individually designed to target mutations specific to each patient’s tumour.
To develop the vaccine, researchers analyse the DNA of a patient’s tumour to identify unique mutations, then create a vaccine intended to train the immune system to recognise and attack cancer cells carrying those mutations.
The Phase 3 trial involved more than 1,100 patients across 157 sites worldwide. All participants had undergone surgery to remove high-risk melanoma. Half received the personalised vaccine alongside Keytruda, an immunotherapy drug, while the remaining participants received Keytruda alone.
The combination treatment reduced the risk of melanoma returning or death by 42 per cent compared with Keytruda alone. Among patients who remained cancer-free six months after beginning treatment, the reduction in risk was even greater, at 58 per cent.
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Limitations of the study
Lead researcher Georgina Long of the Melanoma Institute Australia presented the findings at the 2026 European Society for Medical Oncology (ESMO) Congress. Her colleague Alex Menzies said the approach could eventually be applied to other cancers, particularly those that respond poorly to existing immunotherapies.
However, the results come with several limitations. The complete findings have not yet been published in a peer-reviewed journal, and the 58 per cent reduction was observed in a subgroup of patients, meaning it should be interpreted more cautiously than the main trial result.
Furthermore, personalised mRNA cancer vaccines have not been universally successful. Similar approaches have recently failed to prevent cancer recurrence in trials involving bowel cancer and head and neck cancer, highlighting the challenges of developing effective treatments across different cancer types.
The trial was funded by Moderna and Merck. The vaccine, known as intismeran autogene, has not yet received regulatory approval, and the review process could take years in some countries.
(Edited by Saptak Datta)