A Study of LY3303560 in Healthy Participants and Participants With Alzheimer's Disease (AD)

Single-Dose, Dose-Escalation Study With LY3303560 to Evaluate the Safety, Tolerability, and Pharmacokinetics in Healthy Subjects and Patients With Mild Cognitive Impairment Due to Alzheimer's Disease or Mild to Moderate Alzheimer's Disease

The purpose of this study is to evaluate the safety and tolerability of the study drug, LY3303560. Side effects and laboratory results will be monitored. This study will involve single doses of LY3303560 administered intravenously (IV), meaning into a vein or subcutaneously (SC), meaning under the skin.

Screening is required within 28 days before the start of the study for healthy participants and within 70 days before the start of the study for AD participants. The study requires about 16 weeks of each participant's time including a 4 day clinical research unit (CRU) admission and 10 follow-up appointments.

This is the first time that this study drug is being given to participants. This study is for research purposes only, and is not intended to treat any medical condition.

Inclusion Criteria:

• Overtly healthy males or females of non-childbearing potential and who have given consent and are reliable and willing to make themselves available for the duration of the study and are willing to follow study procedures
• AD participants must be at least 50 years of age and have diagnostic criteria consistent with either mild cognitive impairment due to AD or mild-to moderate AD and have a positive florbetapir positron emission tomography (PET) scan

Exclusion Criteria:

• Have known allergies to LY3303560, related compounds or any components of the formulation, or history of significant atopy
• Have an increased risk of seizures
• For AD participants, evidence of macrohemorrhage or greater than 4 microhemorrhage by magnetic resonance imaging (MRI)