This is the first treatment phase after joining the study. The goal is to reduce the number of cancer cells in the body and achieve remission.

Depending on your specific situation and the treatment arm assigned, you will receive one of several possible medication combinations. The treatment team will determine which approach is appropriate based on your disease characteristics.

If you are in the standard risk group with bone marrow involvement, you may receive either inotuzumab ozogamicin (a targeted therapy given through a vein) or a combination that includes mitoxantrone (a chemotherapy drug given through a vein).

Other medications that may be used during this phase include vincristine sulfate (given through a vein), dexamethasone phosphate (given by mouth or through a vein), daunorubicin hydrochloride (given through a vein), cytarabine (given through a vein or directly into the spinal fluid), methotrexate (given through a vein or directly into the spinal fluid), and pegaspargase (given through a vein).

The specific dosages, frequency, and duration of each medication will be determined by the treatment protocol and your individual response to therapy.

Blood tests and bone marrow examinations will be performed to assess how well the treatment is working and to measure the level of remaining disease cells, known as minimal residual disease or MRD.

After induction therapy, the next phase aims to eliminate any remaining cancer cells and prevent the disease from returning.

The type of consolidation therapy you receive depends on your risk group and how well you responded to induction treatment, particularly your MRD level.

If you are in the standard risk group and achieved a good response (MRD less than one in ten thousand cells after induction), you may receive blinatumomab, which is a type of immunotherapy given as a continuous infusion through a vein over several weeks. This treatment may be given in up to three courses.

If you are in the high risk group and achieved remission after induction, you may receive one course of intensive chemotherapy called HC1 followed by blinatumomab. The chemotherapy course includes medications such as cytarabine, etoposide, and other drugs given through a vein.

If you had an isolated relapse outside the bone marrow (extramedullary relapse) and achieved remission, you will receive consolidation therapy that includes blinatumomab in the later phase of treatment.

Other chemotherapy medications that may be used during consolidation include cyclophosphamide (given through a vein), ifosfamide (given through a vein), vindesine sulfate (given through a vein), prednisolone sodium succinate (given through a vein or by mouth), idarubicin hydrochloride (given through a vein), mercaptopurine (given by mouth), and tioguanine (given by mouth).

Medications may also be given directly into the spinal fluid to prevent or treat disease in the central nervous system.

The duration of consolidation therapy varies depending on the specific treatment plan, but typically involves multiple cycles over several months.

Depending on your risk category and response to treatment, you may be prepared for a stem cell transplant, also known as allogeneic hematopoietic stem cell transplantation or allo-HSCT.

This procedure involves receiving high doses of chemotherapy to eliminate remaining cancer cells, followed by an infusion of healthy stem cells from a donor to rebuild the blood and immune system.

Not all patients will require a stem cell transplant. The decision is based on factors such as your risk group, MRD levels, and overall response to therapy.

If a transplant is planned, additional evaluations and procedures will be performed to prepare for this treatment.

Throughout all phases of treatment, regular monitoring will be performed to assess your response to therapy and manage any side effects.

This includes blood tests, bone marrow examinations, and imaging studies as needed.

Side effects will be monitored and graded according to standard toxicity scales. Any serious adverse events will be documented and managed appropriately.

The presence of CD19 positive cells and CD22 positive cells (specific markers on the surface of leukemia cells) will be checked at various time points to ensure the targeted therapies can work effectively.

For some medications, particularly inotuzumab ozogamicin, blood samples may be collected to measure drug levels in the body and understand how the medication is processed.

Long-term follow-up will continue after the completion of active treatment to monitor for any signs of disease recurrence and to assess overall survival and disease-free survival.