New York: Personalised cancer vaccines are moving closer to clinical use, as advances in mRNA, genomic sequencing and immunotherapy open a new frontier in cancer treatment.
For decades, the idea of a vaccine that could teach the immune system to fight cancer has remained largely experimental. That may now be changing.
A major breakthrough came last month when Moderna and Merck reported positive Phase 3 results for intismeran autogene, an individualised mRNA based cancer treatment developed to reduce the risk of melanoma returning or spreading.
In a trial involving more than 1,000 patients with high risk melanoma, the vaccine, given alongside Merck’s immunotherapy Keytruda, met its key measures for recurrence free and distant metastasis free survival.
Unlike conventional vaccines, which are designed to prevent infections, personalised cancer vaccines are therapeutic. They are built around the genetic characteristics of an individual patient’s tumour.
The process begins by sequencing the tumour after surgery and identifying mutations that distinguish cancer cells from healthy tissue. These mutations can produce neoantigen markers that the immune system may recognise as foreign.
Scientists then use selected neoantigens to create a vaccine designed to train the patient's T cells to identify and attack cancer cells carrying those targets. The National Cancer Institute lists personalised approaches using mRNA, DNA, peptides and viral vectors.
The Moderna Merck results have intensified competition across the sector. Other pharmaceutical companies, including BioNTech and Roche, are developing their own personalised mRNA cancer vaccines, while researchers are testing similar approaches against lung, pancreatic, kidney, colorectal and other cancers.
The development is also creating an unexpected technology race around the treatment itself. Personalised vaccines require sophisticated tumour sequencing to identify targets, while blood based minimal residual disease testing can help determine whether cancer remains after treatment. The emerging market is therefore bringing pharmaceutical companies together with genomic sequencing and diagnostic firms.
Yet significant hurdles remain. Positive Phase 3 results in melanoma do not establish that personalised vaccines will work equally well across other cancers, and longer term survival data are still needed. Manufacturing a separate treatment for individual patients also raises difficult questions about speed, cost, quality control and access.
The United States (US) is already considering how to accelerate the field. A National Cancer Institute advisory committee has proposed a national initiative focused on personalised RNA vaccines, manufacturing capacity, clinical trials and immune monitoring.
The significance of the emerging technology therefore extends beyond a single vaccine. Cancer treatment could be moving towards a model in which a patient's tumour is sequenced, its vulnerabilities identified and an immune based treatment designed specifically around them.
The question is no longer simply whether cancer can be targeted by a vaccine. It is whether medicine can make “one vaccine, one patient” fast, affordable and reliable enough to become routine cancer care.
