The innovation of this protocol is the risk-adapted choice of therapy and the use of a combination of chemotherapy with immunotherapy and hematopoietic stem cell transplantation for patients with risk factors. Investigators have proposed a two-stage stratification into risk groups: Initially: * Standard risk: patients with no rearrangement of the KMT2A gene. * Intermediate risk: patients with rearrangement of the KMT2A gene without damage to the central nervous system. * High risk: patients with rearrangement of the KMT2A gene with lesions of the central nervous system. According to the results of induction therapy: * The high-risk group includes patients from the standard risk group with an MRD level of more than 0.1% after the induction course and from the intermediate risk group with MRD-positive (PCR) after HR1 block. * The allocation of children in the first year of life without the rearranged KMT2A gene into a separate group seems to be logical, since the prognosis in this group is better than in children with the rearranged KMT2A gene. In this protocol, non-intensive therapy with consolidations and maintenance therapy remains for those who achieve a low MRD level (less than 0.1%) after a course of induction. The rest of the patients move into a high-risk group: they receive blinatumomab and HSCT. * The concept of therapy for patients at intermediate risk is based on the rate at which MRD-negativity is achieved: standard consolidation and maintenance therapy for those who became MRD-negative at the end of induction, block chemotherapy for those who were positive at the end of induction, but achieved negativity after HR1 block, blinatumomab with HSCT for those who have preserved the MRD after the HR1 block. * For high-risk patients, a combination of immunotherapy (blinatumomab - a bispecific CD3 / CD19 T-cell activator) and HSCT in the first remission was chosen.