Extension Study of Participants From SPG302-ALZ-101

Inclusion Criteria: * Diagnosis of mild to moderate AD * Clinical laboratory values within normal range or \< 1.5 times ULN * Life expectancy of \>2 years * Able and willing to provide written informed consent * Must have participated in all study activities of SPG302-ALZ-101, the parent study Exclusion Criteria: Any physical or psychological condition that prohibits study completion * Known cardiac disease * Active or history of malignancy in the past 5 years * Serious infection that will not be resolved by first day of study intervention. * History of clinically significant CNS event or diagnosis in the past 5 years. * Acute illness within 30 days of Day 1 * History of suicidal behavior or suicidal ideation * History of chronic alcohol use or substance abuse in the last 5 years * HIV, hepatitis B and/or hepatitis C positive * Vaccines within 14 days * Receipt of investigational products within 30 days * Blood donation within 30 days * Pregnant or breastfeeding