An Extension Study of ABBV-8E12 in Early Alzheimer's Disease (AD)

Number of Participants With Treatment Emergent Adverse Events (TEAEs), Serious TEAEs, TEAEs Leading to Discontinuation of Study Drug, and Fatal TEAEs

Treatment emergent adverse events (TEAEs) are defined as any adverse event (AE) from the time of study drug administration until 20 weeks after discontinuation of study drug. An AE is defined as any untoward medical occurrence, which does not necessarily have a causal relationship with treatment. A serious AE (SAE) is defined as any event that: results in death; is life-threatening; results in hospitalization or prolongation of hospitalization; is a congenital anomaly; results in persistent or significant disability/incapacity; is an important medical event requiring medical or surgical intervention to prevent serious outcome. Severity of AEs was categorized as mild, moderate, or severe. Relationship of the AE to the study treatment was categorized as having a reasonable possibility or no reasonable possibility.

Time frame: From first dose of study drug to 20 weeks after last dose of study drug; overall median time on treatment was 279 days.

Hematology: Number of Participants With Postbaseline Potentially Clinically Significant (PCS) Values

Clinical laboratory PCS criteria were adapted from National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) version 4.03.

Time frame: Baseline to 20 weeks after last dose of study drug; overall median time on treatment was 279 days.

Clinical Chemistry: Percentage of Participants With Postbaseline PCS Values

Clinical laboratory PCS criteria were adapted from NCI CTCAE version 4.03

Time frame: Baseline to 20 weeks after last dose of study drug; overall median time on treatment was 279 days.

Columbia-Suicide Severity Rating Scale (C-SSRS) During Double-Blind Treatment Period

The C-SSRS is a systematically administered instrument developed to track suicidal adverse events across a treatment study. The instrument is designed to assess suicidal behavior and ideation, track and assess all suicidal events, as well as the lethality of attempts. Suicidal ideation categories include the following: wish to be dead; nonspecific active suicidal thoughts; active suicidal ideation without intent to act; active suicidal ideation with some intent to act but no plan; active suicidal ideation with plan and intent. Suicidal behavior categories include the following: actual attempt; interrupted attempt; aborted attempt; preparatory acts or behavior; suicidal behavior; completed suicide.