In the war that is fought against cancer, all soldiers are welcome in the trench. Reinforce the body's own defensive lines (the immune system) with tools to recognize and fight the enemy –immunotherapy– it is one of the strategies lines in the ongoing battle against cancer, but scientists have found no tumor is equal to the neighbor and does not respond the same way to therapies. This particularity that they share of being so different has forced the scientific community to go a step further and design a therapeutic arsenal increasingly directed for each patient, à la carte treatments drawn at the throat for each tumor. The so-called personalized precision medicine is increasingly installed in the fight against cancer. Precisely, an investigation published this Wednesday in Nature has opened the door to fit a precision immunotherapy in patients with glioblastoma, a brain tumor of very poor prognosis (five-year survival is less than 10%). The treatment is a personalized vaccine, comprising tumor antigens from the patient, getting reactivate the immune system to fight cancer cells that system.
"This is the first time that patients with glioblastoma have been treated with personalized vaccines specific to the patient", writes Dr. Fran Martínez Ricarte, neurosurgeon and researcher at the Vall d'Hebron Research Institute (VHIR) .The vaccine works like the immunization that is given every year to fight the flu, only, in this case, instead of made with the strains of the virus, is designed from the antigens of the tumor itself, that is, with the molecules that are in the tumor cells and that function as a kind of DNI, identifying them when the immune system, the defensive army of the organism, If the lymphocytes do not recognize this antigen, they eliminate it. identity card of tumor cells from the patient, it elicits an immune response against these molecules, so that the lymphocytes recognize and kill them.
The research, in which six European centers have participated (from Spain, only the Vall d'Hebron hospital in Barcelona), is a phase I study in which 15 patients with glioblastoma were recruited. "The study was carried out in two phases: in the first, the tumor of 30 patients was analyzed and created as a general library in which the most frequent mutations were chosen in all tumors and more immunogenic, and specific vaccines were generated for this pull of patients, "explains Martínez Ricarte In the clinical phase, the researchers intervened patients to remove the tumor and began to administer the traditional treatment with radiotherapy and chemotherapy At the beginning of the chemo cycles, the scientists administered each of them 15 patients a generic vaccine, made with antigens selected from the 30 patients. After the third cycle of chemotherapy was added to the patient the specific vaccine made with the antigens present exclusively in his.
"The novelty of this study is that the patient was given vaccines that attacked the most immunogenic antigens of his tumor, not any tumor." This study is proof of concept that personalized vaccines for glioblastoma are feasible, useful and open a new treatment route that had not been proven, "says Vall d'Hebron neurosurgeon. The median survival, which is at 14.6 months, reached 29 months in the treated patients.
The experts celebrate the finding but ask for caution: it is a study with few patients and it is still a long way to reach the clinical practice
All in all, Martínez Ricarte celebrates the find but asks for caution and prudence. This is a phase I study, even with few patients and in a type of tumor with high aggressiveness and very poor prognosis. Until this treatment reaches clinical practice – if it arrives – there will still be "a few years". In addition, from the logistic point of view, designing and manufacturing personalized vaccines is not cheap or fast. For the time being, this research, which was financed by the European Union with six million euros, has come to an end and no trial is foreseen to advance to the next step, phase II studies. In any case, the neurosurgeon insists that this study has opened a door to expand the therapeutic arsenal against glioblastomas and the scientific community will not miss that train.