The Personalised Vaccine That Could Cut Skin Cancer Death Risk

A personalised mRNA cancer vaccine, intismeran, used with Keytruda, has shown promising Phase-3 results in reducing recurrence and spread of melanoma.Developed by Moderna and Merck, it is among the first personalised mRNA cancer therapies to demonstrate meaningful clinical benefits.

How Does Intismeran Work?

• The vaccine is customised by identifying cancer-specific mutations called neoantigens from an individual patient’s tumour sample.
• Neoantigens are abnormal proteins found only on cancer cells, enabling the immune system to distinguish and attack tumour cells.
• Each treatment contains mRNA instructions encoding up to 34 tumour-specific neoantigens.
• Once administered, the mRNA directs cells to produce these proteins and trains the immune system to recognise the cancer fingerprint.
• The immune response can create long-term immune memory, helping the body recognise cancer cells if they return.

What Did the Study Find?

• Intismeran combined with Keytruda reduced the risk of recurrence or death by about 49% compared with Keytruda alone.
• The combination reduced the risk associated with cancer spreading to distant parts of the body by about 59%.
• Keytruda itself has improved survival in several cancers, but combining it with a personalised vaccine may provide stronger and more targeted immune protection.
• Common reported side effects included fatigue, injection-site pain and chills.

Why Is It Significant?

• The therapy demonstrates how personalised mRNA technology can train a patient’s immune system against their own cancer mutations.
• Unlike conventional chemotherapy, it offers a highly targeted approach based on the molecular profile of an individual tumour.
• Successful development could expand personalised vaccination beyond melanoma to other cancers carrying identifiable neoantigens.

Significance for India

• The immediate impact may be limited because the trial focused on melanoma, which is relatively uncommon in India.
• Melanoma accounts for only around 0.26% of all cancers in India and about 0.17% of cancer deaths, according to the article.
• High treatment costs remain a major challenge, as many Indian patients already struggle to afford immunotherapy such as Keytruda.
• Wider Indian use would depend on affordability, accessibility and evidence of effectiveness in cancers more common in the Indian population.