Anti-CD19 CAR-T cell theraphy in pediatric patients with relapsed/refractory acute lymphoblastic leukemia. Experience at Hospital Infantil Universitario Niño Jesús

Acute lymphoblastic leukemia (ALL) continues to be the most frequent neoplasm in childhood, with a 5-year survival rate ranging from 78 to 91%. The increase in the survival rate in the last 40 years has been 30 to 80%, with no comparable improvement in the case of relapsed or refractory ALL. It is for this very reason that there is currently research into innovative treatments, such as CAR-T cell therapy. This treatment involves the ex vivo genetic modification of the patient’s own T cells, enhancing their specificity and cytotoxicity against antigens present in the majority of blasts, such as CD19. In clinical trials carried out worldwide, positive results have been obtained in patients with refractory or relapsed ALL treated with CAR-T 19 therapy, with disease-free survival at one year in up to 50% of patients, and overall survival at one year of 76%. The first published report in Spain with respect to this treatment reproduces the results obtained in clinical trials. The results were reported in HNJS in 2020 involving 8 patients treated with CAR-T 19. Complete remission was observed in 87.5% of patients one month after infusion followed by an overall survival of 75% at the time of analysis (7.6 months mean follow-up duration across all the patients). To date, the most frequent side effects described with the use of this therapy in the short term are cytokine release syndrome and neurotoxicity. This innovative therapy, therefore, represents a paradigm shift in the survival of pediatric patients with relapsed or refractory ALL. Further studies and evidence of its effectiveness and the long-term follow-up of patients treated with this therapy are still needed, but the results to date are encouraging.