In the past few hours, msd extension And Modern announced preliminary data on what they call a “personalized mRNA cancer vaccine,” specifically for melanoma, given in combination with an already widely used immunotherapy. The experimental vaccine, which is mRNA exactly like those against Covid, for now has the name of the mRNA-4157 / V940 code and the associated immunotherapy drug is pembrolizumab. For patients who have already had melanoma, this strategy appears to reduce the risk of the disease coming back significantly compared to options already available today. What is it exactly, and what is the scope of the news? Let’s go in order.
The study on the mRna vaccine in operated patients
The results reported by the two companies refer to a phase 2 clinical study conducted on a small group of patients, 157, with completely resected advanced stage (III or IV) melanoma, therefore disease-free at the time of enrollment. “These patients are considered to be at high risk of recurrence, because there may be minimal residual disease, although undetectable,” he explains. Online Paul Ascierto, director of the Melanoma Oncology, Oncological Immunotherapy and Innovative Therapies Unit of the ‘Pascale’ Institute of Naples and president of the Melanoma Foundation. Today, in these cases, immunotherapy is in fact used as an adjuvant treatment, i.e. to reduce the risk of recurrences and metastases: already with pembrolizumab alone or with nivolumab alone (another immunotherapy), 50% of reduction in the risk of relapse or death. “The data released now by Moderna and MDS suggest that adding an mRNA vaccine can further improve this percentage, by 44% compared to pembrolizumab alone. Being a phase 2 study, however, the limit is that these results were obtained on a few patients and will therefore be confirmed in a larger phase 3 study, which will start shortly”.
Therapeutic vaccine and non-preventive vaccine
We are therefore not talking about a preventive vaccine as the one for Covid actually is (and as vaccines are usually understood: that is, as a prophylaxis in healthy people to prevent a disease), but of a therapeutic vaccine, for people who are already ill and who perhaps it would be more correct to always call it immunological therapy. Beyond the semantic question, however, its task is always the same: to train the immune system to recognize an “enemy”, which in this case is cancer cells. On the other hand, the history of mRNA vaccines starts 20 years ago, and it mainly concerned cancer.
It starts with the tumor genome
“The procedure is truly innovative”, continues Ascierto: “According to what is reported, in fact, the genome of the individual patient’s tumor is sequenced: in this way the 34 most significant antigens (proteins, ed) of the tumor are highlighted and on the basis of which messenger RNA is synthesized. Which, injected into the patient, will teach his immune system to recognize them as foreign. We can therefore say that it is a personalized therapeutic vaccine, which however can have the role of preventing metastases “.
The next steps
The announcement of the collaboration for the development and commercialization of mRNA-4157/V940 between the two pharmaceutical companies was made last October. In its release, MSD reports that this is the first demonstration of efficacy within a randomized clinical trial for an mRNA-based anticancer treatment. Serious adverse events occurred in 14.4% of patients receiving the combination vaccine and pembrolizumab, and in 10% of the group receiving immunotherapy alone.” We will begin further studies in melanoma and other cancers with the goal of offering patients truly personalized treatments,” he said Stephane Bancel, ad by Moderna – . We will publish the full data and share the findings at upcoming oncology congresses and with health authorities.”
