Archive · 23 Aug 2026
Personalised cancer vaccine halves melanoma death risk in trial
Scientists have developed a vaccine made specially for each person’s skin cancer.
It studies the tumour to find unusual proteins called neoantigens.
The vaccine uses mRNA instructions to help the body make copies of these proteins.
This teaches the immune system what that person’s cancer looks like.
If cancer returns, the immune system may recognise it more quickly.
In a study, the vaccine was given together with the drug Keytruda.
The combination lowered the risk of death from recurring melanoma by 49% and from spreading melanoma by 59%, compared with Keytruda alone.
The most common side effects were tiredness, pain where the injection was given, and chills.
Doctors said the treatment may not immediately help many people in India because melanoma is uncommon there and Keytruda is expensive.
The personalised mRNA vaccine intismeran is designed using mutations from each patient’s tumour.
When combined with Keytruda, it reduced the risk of death from recurrent melanoma by 49%.
The combination also reduced the risk of death from melanoma that had spread by 59%, compared with Keytruda alone.
The vaccine targets 34 cancer-specific neoantigens to help the immune system recognise returning cancer cells.
Doctors said its immediate impact in India may be limited because melanoma is rare and immunotherapy is often unaffordable.
- Who
- Merck and Moderna developed intismeran; the study involved patients with melanoma receiving Keytruda, with findings discussed by medical experts.
- What
- A personalised mRNA cancer vaccine combined with Keytruda reduced reported risks of death from recurrent or spreading melanoma.
- When
- The article reports Phase 3 findings but does not provide a specific study date.
- Where
- The treatment was discussed in relation to cancer care in India; the article does not specify where the trial took place.
- Why
- The vaccine is intended to train the immune system to recognise and respond to cancer-specific neoantigens if the cancer returns or spreads.
Potential clinical breakthrough
Important current limitations
Effectiveness
Potential clinical breakthrough
The reported Phase 3 findings suggest that adding intismeran to Keytruda substantially lowered the risks of death from recurrent and spreading melanoma.
Important current limitations
The findings compare the combination with Keytruda alone and are specifically for melanoma; the article does not establish benefits for other cancers.
Significance for India
Potential clinical breakthrough
The treatment could represent a new approach to preventing cancer recurrence by creating immune memory against each patient’s tumour.
Important current limitations
Indian oncologists said its immediate impact may be limited because melanoma is rare in India and most patients cannot afford Keytruda, let alone a combination therapy.
- Therapy
- Intismeran, a personalised mRNA cancer vaccine developed by Merck and Moderna
- Combination treatment
- Intismeran was administered with Keytruda
- Reported reduction in death risk
- 49% for recurrence of melanoma and 59% for melanoma spreading, compared with Keytruda alone
- Vaccine design
- Each treatment contains mRNA coding for 34 tumour-specific neoantigens
- Common side effects
- Fatigue, injection-site pain, and chills
- Melanoma in India
- Melanoma accounts for 0.26% of cancer cases and 0.17% of cancer deaths in India, according to Globocan
- Immunotherapy access
- A Tata Memorial Hospital real-world study found that 1.6% of patients who need such immunotherapy could access it