A Study of Mevidalen (LY3154207) in Participants With Alzheimer's Disease

Change from Baseline in Integrated Alzheimer's Disease Rating Scale (iADRS)

Timeframe: Baseline, Week 24

iADRS assesses the impact of cognitive loss on everyday activities and provides a measure of global AD severity as a single summary score. It comprises of 2 underlying domains "cognitive ability" and "functional ability," and integrates the items in both the domains a single overall score ranging from 0 to 144, with lower scores indicating worse performance.

Change from Baseline in Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog13)

Timeframe: Baseline, Week 24

The ADAS-Cog13 consists of 13 items which assess the areas of cognitive function that are the most typically impaired in AD: orientation, verbal memory, language, praxis, delayed free recall, and digit cancellation measures. The scale ranges from 0 to 85, with higher scores indicating greater disease severity.

Change from Baseline in Verbal Fluency Test

Timeframe: Baseline, Week 24

The Verbal Fluency Test, also known as the FAS test, requires participants to say as many words as possible beginning with specific letters (F, A, and S) in 1 minute. The FAS score corresponds to the number of words generated by each participant under each letter category within 1 minute. A higher score indicates better performance.

Change from Baseline in Category Fluency Test

Timeframe: Baseline, Week 24

The Category Fluency test is a measure of semantic memory and involves planning, organization, and cognitive flexibility. The participant is asked to generate as many words as possible in 1 minute that belong to the animal semantic category. Total score is the sum of correct words generated for the animal category, and higher values indicate better performance.

Change from Baseline in Digit Symbol Coding Test( Wechsler Adult Intelligence Scale-IV)(WAIS-IV)

Timeframe: Baseline, Week 24

The Digit Symbol-Coding test from the WAIS-IV involves testing processing speed among subjects; The digit symbol coding requires a subject to match symbols to numbers according to a key. The number of correct symbols within the allowed time constitutes the score, and higher values indicate better performance.

Change from Baseline in Mini Mental State Examination (MMSE)

Timeframe: Baseline, Week 24

The MMSE is a brief instrument used to assess global cognition. The instrument measures orientation, memory, attention, ability to name objects, follow verbal/written commands, write a sentence, and copy figures. Total score ranges from 0 to 30, with lower score indicating greater level of impairment.

Change from Baseline in Alzheimer's Disease Cooperative Study-Activities of Daily Living (ADCS-ADL)

Timeframe: Baseline, Week 24

The ADCS-ADL is a 23-item inventory developed as a rater-administered questionnaire that is to be answered by the participant's study partner. Study partner is asked to observe and rate the performance of activities of daily living attempted by participants. The range for the total ADCS-ADL score is 0 to 78, with lower scores indicating greater level of impairment.

Alzheimer's Disease Cooperative Study-Clinical Global Impression of Change score (ADCS-CGIC)

Timeframe: Week 24

The ADCS-CGIC is a 7-point, categorical scale that provides a single global rating of change from baseline. A score of 1 indicates marked improvement; a score of 2, moderate improvement; a score of 3, minimal improvement; a score of 4, no change; a score of 5, minimal worsening; a score of 6, moderate worsening; and a score of 7, marked worsening.

Change from Baseline on Neuropsychiatric Inventory (NPI-12)

Timeframe: Baseline, Week 24

The NPI-12 is rating instrument to assess abnormal behaviors in dementia patients by informant-based interview that utilizes scripted questions to explore 12 different symptom domains: delusions, hallucinations, agitation/aggression, dysphoria, anxiety, euphoria, apathy, disinhibition, irritability/lability, aberrant motor activity, night-time behavioral disturbances, and appetite and eating abnormalities. The frequency of behaviour is scored from 0 (Rarely) to 4 (very often) and the severity from 0 (mild) to 3 (severe). A total score for each symptom is calculated by multiplying the frequency rating by the severity rating. The total NPI-12 score is the sum of all symptom scores and ranges from 0 to 144, with higher scores indicating a greater degree of symptomatology.

Change from Baseline on Epworth Sleepiness Scale (ESS)

Timeframe: Baseline, Week 24

ESS is an 8-item questionnaire that measures the chances of "dozing off" in different daytime situations over the past week. Scores range from 0 to 24, with scores greater than or equal to 10 indicating excessive daytime sleepiness.

Change from Baseline on Quick Dementia Rating Scale (QDRS)

Timeframe: Baseline, Week 24

The QDRS is a 10-item rating scale that assesses aspects of cognition, behavior, and daily functioning on a 5-point scale where no problems = 0, slight problems = 0.5, mild problems = 1, moderate to severe problems = 2, and severe problems = 3. Total scores range from 0 to 30 and higher scores indicate increased cognitive impairment.