Study To Evaluate the Efficacy, Safety and Tolerability of E2027 (Hereinafter Referred to as Irsenontrine) in Participants With Dementia With Lewy Bodies

Number of participants are reported categorized in grades based on the CGIC-DLB scale. The CGIC-DLB scale provided an overall clinician-determined summary measure of change from the participant's clinical status that takes into account all available information from the efficacy endpoints (which include cognitive function, non-cognitive symptoms, behavior, and the impact of the symptoms on the participant's ability to function) and safety data. The (CGIC-DLB) was a 7-point scale and scores were: 1 (marked improvement), 2 (moderate improvement), 3 (minimal improvement), 4 (no change), 5 (minimal worsening), 6 (moderate worsening), and 7 (marked worsening). Higher values represent a worse outcome.

The CFI scale assessed cognitive fluctuation. It evaluates fluctuation in various domains including attention, ability to perform daily functions, orientation, verbal communication and behavior. The score was based on frequency and severity with a score range of 0 to 12. The scale also assessed the degree of caregiver or informant distress engendered by the symptoms. Higher scores indicating greater impairment.

The MMSE is a 30-point scale that measured orientation to time and place, registration, immediate and delayed recall, attention, language, and drawing. The total score ranges from 0 (most impaired) to 30 (no impairment). The lower score means severe cognitive deficit and higher score indicates better function.

The NPI-12 scale assessed the frequency and severity of 12 neuropsychiatric symptoms commonly described in dementia participants: delusions, hallucinations, agitation/aggression, depression/dysphoria, anxiety, elation/euphoria, apathy/indifference, disinhibition, irritability/lability, motor disturbance, nighttime behaviors, and appetite/eating changes. The scale also assessed the degree of caregiver or informant distress engendered by each of the symptoms. The sum of the composite scores for the 12 domains yielded the NPI-12 total score. NPI-12 total score ranged from 0 (minimum severity) to 144 (maximum severity); higher score indicates greater neuropsychiatric disturbance.

The NPI scale assesses the frequency and severity of 12 neuropsychiatric symptoms commonly described in dementia participants: delusions, hallucinations, agitation/aggression, depression/dysphoria, anxiety, elation/euphoria, apathy/indifference, disinhibition, irritability/lability, motor disturbance, nighttime behaviors, and appetite/eating changes. NPI-4 is the subscore covering the domains of delusions, hallucinations, apathy and depression. NPI-4 total subscore ranged from 0 to 48, with higher scores indicating a greater neuropsychiatric disturbance.

The NPI-10 assessed range of behaviors seen in dementia for both frequency and severity. It is a 10 item questionnaire with the following domains: delusions, hallucinations, agitation/aggression, depression/dysphoria, anxiety, elation/euphoria, apathy/indifference, disinhibition, irritability/liability and aberrant motor behavior. The total score was a sum of the 10 domains, where the score of each domain was calculated as frequency (scale: 1=occasionally to 4=very frequently)*Severity (scale: 1=Mild to 3=Severe). Each domain has a maximum score of 12 and all domains were equally weighted for total score, the range for total score is 0 to 120. Higher scores indicating a greater neuropsychiatric disturbance.

The NPI-D scale assesses the frequency and severity of 12 neuropsychiatric symptoms commonly described in dementia participants: delusions, hallucinations, agitation/aggression, depression/dysphoria, anxiety, elation/euphoria, apathy/indifference, disinhibition, irritability/lability, motor disturbance, nighttime behaviors, and appetite/eating changes. The scale assesses the degree of caregiver distress engendered by each of the symptoms. The caregiver distress (NPI-D) is rated by caregiver based on his or her own stress on a five point scale from 0 to 5, where: 0(no distress), 1(minimal), 2(mild), 3(moderate), 4(moderately severe), 5(very severe or extreme). NPI-D total score is calculated by summing the scores of the 12 sub-scale distress scores. The NPI-D total scores ranges from 0 to 60 with higher scores indicating greater distress.

A TEAE was defined as an AE that emerged or worsened in severity relative to baseline during treatment or within 28 days after the last dose of study drug. Severe TEAE was defined as inability to work or to perform normal daily activity. A Serious TEAE is any untoward medical occurrence that at any dose: results in death; is life threatening (that is, the participant was at immediate risk of death from the adverse event as it occurred; this does not include an event that, had it occurred in a more severe form or was allowed to continue, might have caused death) requires inpatient hospitalization or prolongation of existing hospitalization; results in persistent or significant disability/incapacity; is a congenital anomaly/birth defect or is medically important due to other reasons than the above mentioned criteria. An adverse event (AE) was defined as any untoward medical occurrence in a participant administered an investigational product.

Orthostatic hypotension was defined as drop in standing systolic blood pressure greater than or equal to (>=) 20 Millimeter of mercury (mmHg) compared to supine, or drop in standing diastolic blood pressure >=10 mmHg compared to supine.

Orthostatic tachycardia by numerical criteria was defined by the following numerical criteria: Standing heart rate (HR) increased by >30 beats/min compared to supine and absolute standing HR was >100 beats/min.

A laboratory value was determined to be a markedly abnormal value if the postbaseline common toxicity criteria grade increased from baseline and the post-baseline grade was greater than or equal to 2.

The C-SSRS (mapped to Columbia Classification Algorithm of Suicide Assessment (C-CASA) categories); is an interview-based instrument to systematically assess suicidal ideation and suicidal behavior. C-SSRS assess whether participant experience any of the following: completed suicide; suicide attempt (response of "yes" on "actual attempt"); preparatory acts toward imminent suicidal behavior ("yes" on "preparatory acts or behavior", "aborted attempt" or "interrupted attempt"), suicidal ideation ("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 self-injurious behavior with no suicidal intent ("yes" on "has participant engaged in non-suicidal self-injurious behavior"). Here, number of participants with positive response ("yes") to suicidal behavior or/and Ideation, any non-suicidal self-injurious behavior was reported.

The UPDRS scale evaluates extrapyramidal features in motor function in Parkinson's disease. It contains 33 items in 18 categories: (1) speech, (2) facial expression, (3) rigidity, (4) finger tapping, (5) hand movements, (6) supinational and pronation movements of hands, (7) toe tapping, (8) leg agility, (9) arising from chair, (10) gait, (11) freezing of gait, (12) postural stability, (13) posture, (14) body bradykinesia, (15) postural tremor of hands, (16) kinetic tremor of hands, (17) rest tremor amplitude and (18) constancy of rest tremor. Each item is scored 0 to 4, giving a total score range 0 to 132. Higher scores indicating more severe symptoms.