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

This is significant news. The results are not being presented, as there is no scientific publication; instead, the interim results of a phase 3 trial are being announced. The announcement has been made ahead of the publication, and it is stated that the findings will be presented at a conference.

Why has this attracted so much attention? Firstly, it is a phase 3 trial involving more than a thousand melanoma patients, and secondly, because of the technology involved. These are personalised vaccines, tailored to each individual patient. This is achieved, firstly, by sequencing the DNA to identify mutations. Then, by sequencing both normal and tumour DNA; and subsequently, by sequencing at the RNA level, to determine how many of these alterations are expressed and which ones can be recognised by the immune system.

This is one part of the treatment. The other part involves combining it with pembrolizumab to reduce all the inhibitory mechanisms that cells employ within the immune system—their multiple defence mechanisms. Furthermore, the aim is to ensure that the immune system actively recognises the tumour. This is why this other component of the treatment is included, and the result is the identification of up to 34 factors that are altered and expressed in the tumour cell.

The trial was conducted as an adjuvant treatment, that is, following surgery. The tumours (primary tumours, lymph nodes, and it appears some metastases too) have been removed. What is measured is how long it takes for the tumour to reappear after surgery, disease-free survival and metastasis-free survival.

Why is this interesting? Because of the RNA technology. Until now, there was no way to identify 34 alterations in proteins specific to a particular patient, and they have combined this with this immunomodulator. The idea is to get the immune system to attack these tumour cells as much as possible.

What remains to be done? Well, first we need to see the final results. And what is perhaps a cause for concern is how widely applicable it will be, as this varies from patient to patient; and also the cost to healthcare systems – whether such a personalised treatment is affordable. Perhaps in the future, alterations that are very common may be identified, but at the moment it is personalised.

In principle, the prospects are very promising – albeit with caution – for a technologically very complex trial.”