Open-label Extension Study in Participants With Early Alzheimer's Disease

Prior treatment

• Participant is taking or will be starting a prohibited medication described in the protocol.

Other illness

• Other newly identified intracranial hemorrhage aneurysm, vascular malformation, infective lesion, space occupying lesion or brain tumor, or other Magnetic resonance imaging (MRI) findings contraindicating participation in the study.
• Newly identified infection(s) that may affect the Central nervous system (CNS).
• New diagnosis of moderate to severe alcohol and/or substance use disorder.
• Newly diagnosed cancer.
• Newly identified severe allergic, anaphylactic, or other hypersensitivity reactions to chimeric, human, or humanized antibodies or fusion proteins.
• Newly identified genetic predisposition for clotting disorder or hemorrhagic disease.

Lab values

• QT interval corrected (QTc) assessment at Day 1 that meets the stopping criteria described in the protocol.

Other

• Evidence of any Amyloid related imaging abnormalities (ARIA) or cerebral macrohemorrhage that meets the permanent discontinuation criteria described in the protocol.
• Change in participant's ability to tolerate MRI procedures, contraindication to MRI, or any other clinical history or examination finding that would pose a potential hazard in combination with MRI.
• Any other clinically significant change in health status (which, in the opinion of the investigator, would make the participant unsuitable for participation in the OLE study.

• Completion of the Treatment Period in the parent study (NCT06079190).
• Participants may have missed doses during the Treatment Period or may be on a temporary dose suspension but must not have been permanently discontinued early from study intervention or withdrawn from the parent study.
• Willing and able to give informed consent, which includes compliance with the requirements and restrictions listed in the informed consent form (ICF).
• Availability of an adult person who has frequent and sufficient contact with the participant, is able to provide accurate information regarding the participant's cognitive and functional abilities, agrees to provide information at clinic visits, and signs the study partner ICF.
• A female participant is eligible to participate if she is not pregnant or breastfeeding, and if of childbearing potential follows contraception requirements outlined in the protocol.
• A male participant is eligible to participate if he follows contraception requirements outlined in the protocol.