Cancer Vaccines

A therapeutic cancer vaccine trains the immune system to recognise neoantigens — mutated proteins present on a patient's tumour cells but not on healthy ones — so it will destroy cells carrying them. The idea is one of immunotherapy's oldest and, until 2026, one of its most notorious failures: billions spent, no durable success.

Why earlier vaccines failed

Single targets — a tumour can simply stop making one protein.
Wrong targets — some early vaccines aimed at proteins that did not matter.
Immune suppression — tumours switch off the response the vaccine is trying to raise.

The arrival of checkpoint inhibitors (which block that suppression) reopened the question: would a vaccine work if given alongside one?

What changed: personalised mRNA

mRNA platforms built for infectious-disease vaccination let a vaccine encoding a specific patient's tumour neoantigens be manufactured in weeks. The first product is intismeran autogene (Moderna + Merck), given with pembrolizumab.

The evidence so far (interim, August 2026)

Population: patients with completely resected stage IIB–IV cutaneous melanoma, no prior systemic therapy (phase 3 INTerpath-001).
Result: the vaccine + pembrolizumab arm met the primary endpoint, recurrence-free survival, and a key secondary endpoint, distant metastasis-free survival, versus pembrolizumab alone. Effect sizes were not disclosed in the interim release; detailed data were scheduled for ESMO 2026.
Interpretation (The Economist): by implication the neoantigen idea works.

Caveats the article itself lists

Delayed recurrence may not mean longer survival.
The size of the benefit and the cost are unknown; could be marginal and expensive.
Melanoma is unusually immunogenic — other cancers may not respond.
Trials in lung, bladder and kidney cancer (under way) and the full melanoma data will decide whether this is a breakthrough.

Proposed role

Mopping up microscopic residual disease after surgery — the clusters that later return as tumours — and thereby reducing reliance on radiation and chemotherapy.

It Now Seems Possible to Vaccinate Against Cancer (Economist) — source article (2026-08-29).
KRAS Inhibitors — daraxonrasib, approved the same week; KRAS inhibition may make immune-cold tumours more vaccine-susceptible (hypothesis).
Lung Cancer Screening and Prevention — lung cancer is a next vaccine target, and the IL-1β work there is the prevention-side counterpart to vaccination against recurrence.