Study Evaluating The Safety Of AAB-003 (PF-05236812) In Subjects With Alzheimer's Disease

Criteria for potential clinical concern in vital signs included: supine/sitting pulse rate of less than (<) 40 or more than (>) 120 beats per minute (bpm), and standing pulse rate of <40 or >140 bpm; systolic blood pressure (SBP) of more than or equal to (>=)30 millimeters of mercury (mm Hg) change from baseline in same posture and <90 mm Hg; diastolic blood pressure (DBP) >=20 mm Hg change from baseline in same posture and <50 mm Hg. Only supine vital signs were planned for this study. Unplanned sitting vital signs were collected only in the 8/mg and placebo groups and also reported.

The neurological examination was done to the extent needed to assess the participant for any potential changes in neurological status, as determined by the investigator. The minimum items assessed were level of consciousness, speech, cranial nerves, motor, sensory, coordination, gait, and tendon reflexes.

The C-SSRS assessed whether the participant experienced the following: completed suicide (1), suicide attempt (2) (response of "Yes" on "actual attempt"), preparatory acts toward imminent suicidal behavior (3)("Yes" on "preparatory acts or behavior"), suicidal ideation (4) ("Yes" on "wish to be dead", "non-specific active suicidal thoughts", "active suicidal ideation with methods without intent to act or some intent to act, without specific plan or with specific plan and intent), any suicidal behavior or ideation, self-injurious behavior (7)("Yes" on "Has participant engaged in non-suicidal self-injurious behavior").

Brain MRIs were collected during the course of study to assess for any potential drug-related changes that might have constituted a safety concern for study participants. Findings suggestive of either vasogenic edema (VE) or intracranial hemorrhage represented adverse events of special circumstance and were to be reported immediately.

VE of the brain, identified via MRI, was identified as an adverse event of special circumstance.

Criteria for ECG values of potential clinical concern are: interval between the start of the ECG P wave and the start of the QRS complex corresponding to the time between onset of atrial depolarization and onset of ventricular depolarization (PR): >= 300 milliseconds (msec), and >=25% increase when baseline >=200 msec/ >=50% increase when baseline less than or equal to (<=) 200 msec; time from ECG Q wave to the end of S wave corresponding to ventricular depolarization (QRS): >=200 msec, and >=25% increase when baseline >100 msec/ >=50% increase when baseline <=100 msec; QTc using Fridericia's formula (QTcF) interval: 450 to <480 msec, >=480 msec; QTcF change from baseline: 30 to <60 msec, and >=60 msec.

Human serum anti-drug antibodies (ADA) samples were analyzed for the presence or absence of anti-AAB-003 antibodies by enzyme-linked immunosorbent assay (ELISA) method

The ADAS-cog 70 Point is a structured scale (approximately 40 min to complete) that evaluates memory, orientation, attention, reasoning, language and constructional praxis. This study used the 11-item cognitive subscale of the ADAS-Cog with scores ranging from 0 to 70 points; higher scores indicated greater cognitive impairment.

The DAD is a functional assessment based on an interview with the caregiver that takes approximately 20 min to administer and it is comprised of 40 items, 17 related to self-care and 23 items involving instrumental activities of daily living. The DAD is scored from 0 to 100 (higher scores indicate better functioning).

The NPI is an instrument used to assess changes of behavior that have appeared in a defined period of time in participants with Alzheimer's disease (AD) and other dementias. Twelve (12) behavioral areas are assessed in the NPI - delusions, apathy, hallucinations, disinhibition, agitation, irritability, depression, aberrant motor behavior, anxiety, nighttime behaviors, euphoria, appetite, and eating changes. The NPI score is based on frequency and severity of specific behaviors within these categories as reported by the caregiver. A separate caregiver distress score may also be included. The NPI ranges from 0 to 144 (higher scores indicate greater psychopathology).

The CDR scale is a clinician-rated dementia staging instrument that tracks the progression of cognitive impairment in the following 6 categories - memory, orientation, judgment and problem solving, involvement in community affairs, home and hobbies, and personal care based on the CDR interview. The CDR is based on discussions between the clinician with the participant and caregiver using a structured format. A global CDR score is established by clinical scoring rules with values of 0 (no dementia), 0.5 (questionable dementia), 1 (mild dementia), 2 (moderate dementia), and 3 (severe dementia). A more quantitative version of the CDR scale is obtained by summing up the ratings in each of the 6 categories to provide the (CDR-SB). The CDR-SB scale ranges from 0 to 18 where higher score indicates severe dementia.

The MMSE is a brief 30-point questionnaire test that is used to assess cognition. It is commonly used to screen for dementia. In the time span of about 10 min, it samples various functions, including arithmetic, memory and orientation. Scores range from 0 to 30 (higher scores indicate less impairment) and participants with scores of 16 to 26 were eligible.

Participants enrolled in the 2, 4 and 8 mg/kg cohorts participated in an optional CSF collection. Participants enrolled in the maximum tolerated dose (MTD) cohort were mandatorily collected for CSF.