Reacción a "Pharmaceutical companies Moderna and Merck have announced preliminary successes in the Phase 3 trial of their personalised melanoma vaccine"

What is this personalised cancer vaccine and how does it work?

“A personalised cancer vaccine is designed by first identifying mutations in the DNA of a cancer and then working out which mutations encode for proteins that get presented to immune cells on the surface of the cancer cells. Over 30 such mutations can then be selected for vaccine manufacturing. As the selection is done for each individual cancer, it is a personalised product. The vaccine technology is very similar to many Covid vaccines which use RNA. RNA that encodes the identified mutations is then injected under the skin ever 3 weeks and at the same time patients received another immunotherapy called pembrolizumab. The idea is that the personalised neoantigen vaccine educates the immune cells to recognize the cancer cells whereas pembrolizumab takes the breaks off the immune cells and helps them to have maximum effect.    

What can we know from these results? What details are still to come?

“The press release only announced that the study is positive, and we don’t have any details yet. The main aim of the study was to show that recurrence free survival improves when patients receive the vaccine. This has been achieved but we don’t know yet how much lower the recurrence rate for example at 3 years is. These results may be presented at one of the big oncology conferences in autumn. How much long-term survival improves is almost certainly not know yet as the patients will need to be followed for longer but recurrence free survival correlates well with this. 

How significant are these findings?

“I think it is fair to call it a breakthrough in the development of new cancer immunotherapies as it is the first phase 3 study that shows that a vaccine can protect against recurrences of one of the deadliest cancer types. This is certainly good news for patients with melanoma, but the study has much wider implications. It provides proof of principle that personalised cancer vaccines work. This is important as they can be designed against many different cancer types. I am hopeful that we will see similar successes of this technology in a range of cancer types such as colon cancer where a large study has been performed.“