Prevention of adverse effects caused by CD3 specific binding domains

A method for preventing, ameliorating, or treating an adverse neurological event in a subject,

• wherein the adverse neurological event is confusion, loss of memory, ataxia, speech disorder, disorientation, seizures, encephalopathy, cerebral edema, hallucinations, apraxia, paresis, or tremor caused by administering to the subject an antibody or fragment thereof comprising a CD3 binding domain comprising an anti-CD3 heavy chain comprising a CDR-H1 comprising the amino acid sequence of SEQ ID NO:
• 11, a CDR-H2 comprising the amino acid sequence of SEQ ID NO:
• 12, and a CDR-H3 comprising the amino acid sequence of SEQ ID NO:
• 13, and an anti-CD3 light chain comprising a CDR-L1 comprising the amino acid sequence of SEQ ID NO:
• 14, a CDR-L2 comprising the amino acid sequence of SEQ ID NO:
• 15, and a CDR-L3 comprising the amino acid sequence of SEQ ID NO:
• 16,
• the method comprising the step of administering an effective amount of a glucocorticoid (GC) to the subject prior to or concurrently with administering a first dose of the antibody or fragment thereof comprising the CD3 binding domain, and prior to the presence of the adverse neurological event in the subject.