This study aims to prevent neurotoxicity (damage to the brain or nerves) caused by a drug called blinatumomab used for treating Acute Lymphoblastic Leukemia (ALL), a type of blood cancer. This is done by changing when another drug, intrathecal chemotherapy, is given. This chemotherapy is injected into the space around the spinal cord. The goal is to keep the cancer-fighting effects of blinatumomab while reducing the risk of brain or nerve damage.

To join this study, participants must be adults starting blinatumomab for relapsed or difficult-to-treat ALL and have good liver and kidney function. They cannot have certain brain or nerve disorders, other cancers, or infections.

• Duration: The study involves multiple visits for monitoring.
• Compensation: Participants may receive compensation for their time and travel.
• Risks: Possible side effects include typical chemotherapy risks and potential nerve damage.