The purpose of this study is to assess safety, tolerability, plasma pharmacokinetics and biologic activity of a single intravenous dose of AMDX-2011P in participants with cerebral amyloid angiopathy (CAA).

This open-label, masked endpoint assessment study will evaluate the safety, tolerability, plasma pharmacokinetics (PK) and biological activity of an intravenous (IV) dose of AMDX-2011P in participants with CAA. Assessments of retinal images will be conducted by central masked assessors.

Participants will be admitted to the study site where eye examination and retinal imaging will be conducted before administration of the study drug. AMDX-2011P will be administered through a single IV bolus injection followed by safety assessments, retinal imaging and PK blood collection.

Inclusion Criteria:

1. Diagnosis of hereditary CAA or probable and definite symptomatic or asymptomatic sporadic CAA diagnosed through genetic testing or according to the modified Boston neuroradiological criteria, who had undergone at least one brain magnetic resonance imaging (MRI)prior to entry into study.
2. Abnormality consistent with CAA on historical MRI.
3. In general good health

Exclusion Criteria:

1. Presence of any underlying physical or psychological medical condition that, in the opinion of the investigator, would make it unlikely that the participant will complete the study per protocol.
2. Clinically significant laboratory abnormalities assessed by the investigator.
3. Active malignancy and/or history of malignancy in the past 5 years, with the exception of completely excised non-melanoma skin cancer or low-grade cervical intraepithelial neoplasia.
4. Prolonged QTcF (>450 ms for males and >470 ms for females),cardiac arrhythmia, or any clinically significant abnormality in the resting ECG, as judged by the investigator.