Methods of treatment using p-tau181 level

A method of treating or preventing Alzheimer's disease (AD) in a subject having or suspected of having AD, comprising:

• a. measuring or having measured a level of p-tau181 in a blood sample obtained from the subject;
• and
• b. administering a treatment comprising a therapeutically effective dose of an anti-amyloid β (Aβ) protofibril antibody to the subject having a p-tau181 level above a threshold that indicates amyloid positivity,
• wherein the anti-Aβ protofibril antibody comprises a heavy chain variable region comprising an amino acid sequence of SEQ ID NO:
• 7 and a light chain variable region comprising an amino acid sequence of SEQ ID NO:
• 8.

A method of treating Alzheimer's disease (AD) in a subject who has received treatment for AD, comprising:

• a. measuring or having measured a level of p-tau181 in a blood sample obtained from the subject;
• and
• b. administering a therapeutically effective dose of an anti-amyloid β (Aβ) protofibril antibody according to a maintenance dosing regimen to the subject having a p-tau181 level at or below a threshold of about 3.4 pg/mL,
• wherein the anti-Aβ protofibril antibody comprises a heavy chain variable region comprising an amino acid sequence of SEQ ID NO:
• 7 and a light chain variable region comprising an amino acid sequence of SEQ ID NO:
• 8.