Treatment of acute lymphoblastic leukemia

A method for treating acute lymphoblastic leukemia (ALL) minimal residual disease (MRD) in an adult patient in hematological remission, the method comprising

• selecting the patient in hematological remission;
• and
• administering to the patient an effective amount of a composition comprising a CD19×CD3 bispecific single chain antibody construct comprising a variable heavy chain anti-CD19 CDR1 comprising the amino acid sequence set forth in SEQ ID NO:
• 14, a variable heavy chain anti-CD19 CDR2 comprising the amino acid sequence set forth in SEQ ID NO:
• 15, a variable heavy chain anti-CD19 CDR3 comprising the amino acid sequence set forth in SEQ ID NO:
• 16, a variable light chain anti-CD19 CDR1 comprising the amino acid sequence set forth in SEQ ID NO:
• 11, a variable light chain anti-CD19 CDR2 comprising the amino acid sequence set forth in SEQ ID NO:
• 12, a variable light chain anti-CD19 CDR3 comprising the amino acid sequence set forth in SEQ ID NO:
• 13, a variable heavy chain anti-CD3 CDR1 comprising the amino acid sequence set forth in SEQ ID NO:
• 17, a variable heavy chain anti-CD3 CDR2 comprising the amino acid sequence set forth in SEQ ID NO:
• 18, a variable heavy chain anti-CD3 CDR3 comprising the amino acid sequence set forth in SEQ ID NO:
• 19;
• a variable light chain anti-CD3 CDR1 comprising the amino acid sequence set forth in SEQ ID NO:
• 20, a variable light chain anti-CD3 CDR2 comprising the amino acid sequence set forth in SEQ ID NO:
• 21, and a variable light chain anti-CD3 CDR3 comprising the amino acid sequence set forth in SEQ ID NO:
• 22,
• wherein treatment results in stable disease or converts MRD-positive ALL into MRD-negative ALL.