| E.1 Medical condition or disease under investigation | 
| E.1.1 | Medical condition(s) being investigated |  | 
| E.1.1.1 | Medical condition in easily understood language |  | 
| E.1.1.2 | Therapeutic area | Diseases [C] - Nervous System Diseases [C10] | 
| MedDRA Classification | 
| E.1.2 Medical condition or disease under investigation | 
| 
| E.1.2 | Version | 18.1 |  
| E.1.2 | Level | LLT |  
| E.1.2 | Classification code | 10001896 |  
| E.1.2 | Term | Alzheimer's disease |  
| E.1.2 | System Organ Class | 100000004852 |  | 
| E.1.3 | Condition being studied is a rare disease | No | 
| E.2 Objective of the trial | 
| E.2.1 | Main objective of the trial | 
| Open-label treatment period (initial 28 weeks): To evaluate the long-term safety and tolerability of idalopirdine as adjunctive therapy to donepezil in patients with mild-moderate AD. Open-label treatment period with memantine (sub-study): To evaluate the safety and tolerability of concomitant treatment with idalopirdine, memantine and donepezil in patients with AD.
 |  | 
| E.2.2 | Secondary objectives of the trial | 
| Open-label treatment period (initial 28 weeks): To evaluate the disease development during long-term treatment with idalopirdine as adjunctive therapy to donepezil. Open-label treatment period with memantine (sub-study): To evaluate the disease development during concomitant treatment with idalopirdine, memantine and donepezil in patients with AD.
 |  | 
| E.2.3 | Trial contains a sub-study | Yes | 
| E.2.3.1 | Full title, date and version of each sub-study and their related objectives | 
| Open-label treatment period with memantine |  | 
| E.3 | Principal inclusion criteria | 
| Open-label treatment period (initial 28 weeks): • The patient has completed Visit 7 (Completion Visit) in the lead-in double-blind, placebo controlled clinical studies 14861A or 14862A.
 
 Open-label treatment period with memantine (sub-study):
 Major inclusion criteria at Baseline III:
 * The patient has completed Visit 6 [(i.e., the open-label treatment period (initial 28-week period)].
 * The patient has a MMSE score at Visit 6 not greater than 19 in accordance with the memantine label/summary of product characteristics (SmPC).
 * The patient, according to the judgement of the investigator, requires initiation of
 treatment with memantine as per locallabei/SmPC/treatment guidelines.
 |  | 
| E.4 | Principal exclusion criteria | 
| • The patient has a moderate or severe ongoing adverse event from the lead-in study considered a potential safety risk by the investigator. • The patient has experienced seizures before Completion Visit in the lead-in study.
 • The patient has evidence of clinically significant disease.
 • The patient's donepezil treatment is likely to be interrupted or discontinued during the study.
 • The patient is receiving therapy with another AChEI or memantine.
 
 Open-label treatment period with memantine (sub-study):
 Major exclusion criteria at Baseline III:
 * The patient exhibits an increase in MMSE score by 3 points or more at Visit 6 from Baseline II.
 * The patient has a moderate or severe on-going adverse event from the open-label treatment period (initial 28-week period) considered a potential safety risk by the investigator.
 * The patient has a previous history of testing positive for hepatitis B surface antigen (HBsAg), or hepatitis C virus / antibodies (anti-HCV) AND had abnormal ALT, AST or bilirubin during the open-label treatment period (initial 28-week period).
 * The patient has tested positive for hepatitis B surface antigen (HBsAg), or hepatitis C virus /antibodies (anti-HCV) for the frrst time within the last 6 months prior to the Visit 6 in the open-label treatment period (initial 28-week period).
 * The patient has one or more clinical laboratory test values outside the reference
 range, based on the latest available blood and urine sample results during the open-label treatment period (initial 28-week period), that are of potential risk to the patient's safety, or the patient has according to the latest available blood sample:
 - a serum creatinine value >1.5 times the upper limit of the reference range, or
 - a serum total bilirubin value >1.5 times the upper limit of the reference range, or
 - a serum alanine aminotransferase (AL T) or aspartate aminotransferase (AST)
 value >2 times the upper limit ofthe reference range.
 |  | 
| E.5 End points | 
| E.5.1 | Primary end point(s) | 
| • Safety: Number of adverse events • Tolerability: Number of withdrawals
 |  | 
| E.5.1.1 | Timepoint(s) of evaluation of this end point | 
| Up to 28 weeks and a 4-week safety follow-up |  | 
| E.5.2 | Secondary end point(s) | 
| • Change in cognition: Change in Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-Cog) total score • Change in global impression: Alzheimer's Disease Cooperative Study - Clinical Global Impression of Change (ADCS-CGIC) score
 • Change in functioning: Change in Alzheimer's Disease Cooperative Study - Activities of Daily Living Inventory (ADCS-ADL23) total score
 • Change in behavioural disturbance: Change in Neuropsychiatric Inventory (NPI) total score
 • Change in cognitive aspects of mental function: Change in Mini Mental State Examination (MMSE)
 • Risk of Suicidality Using C-SSRS Scores: Columbia Suicide Severity Rating Scale (C-SSRS)
 |  | 
| E.5.2.1 | Timepoint(s) of evaluation of this end point | 
| Baseline and Week 28 for all, except for Risk of Suicidality which is up to week 28. |  | 
| E.6 and E.7 Scope of the trial | 
| E.6 | Scope of the trial | 
| E.6.1 | Diagnosis | No | 
| E.6.2 | Prophylaxis | No | 
| E.6.3 | Therapy | Yes | 
| E.6.4 | Safety | Yes | 
| E.6.5 | Efficacy | Yes | 
| E.6.6 | Pharmacokinetic | No | 
| E.6.7 | Pharmacodynamic | No | 
| E.6.8 | Bioequivalence | No | 
| E.6.9 | Dose response | Yes | 
| E.6.10 | Pharmacogenetic | No | 
| E.6.11 | Pharmacogenomic | No | 
| E.6.12 | Pharmacoeconomic | Yes | 
| E.6.13 | Others | No | 
| E.7 | Trial type and phase | 
| E.7.1 | Human pharmacology (Phase I) | No | 
| E.7.1.1 | First administration to humans | No | 
| E.7.1.2 | Bioequivalence study | No | 
| E.7.1.3 | Other | No | 
| E.7.1.3.1 | Other trial type description |  | 
| E.7.2 | Therapeutic exploratory (Phase II) | No | 
| E.7.3 | Therapeutic confirmatory (Phase III) | Yes | 
| E.7.4 | Therapeutic use (Phase IV) | No | 
| E.8 Design of the trial | 
| E.8.1 | Controlled | No | 
| E.8.1.1 | Randomised | No | 
| E.8.1.2 | Open | Yes | 
| E.8.1.3 | Single blind | No | 
| E.8.1.4 | Double blind | No | 
| E.8.1.5 | Parallel group | No | 
| E.8.1.6 | Cross over | No | 
| E.8.1.7 | Other | No | 
| E.8.2 | Comparator of controlled trial | 
| E.8.2.1 | Other medicinal product(s) | No | 
| E.8.2.2 | Placebo | No | 
| E.8.2.3 | Other | No | 
| E.8.2.4 | Number of treatment arms in the trial | 1 | 
| E.8.3 | The trial involves single site in the Member State concerned | No | 
| E.8.4 | The trial involves multiple sites in the Member State concerned | Yes | 
| E.8.4.1 | Number of sites anticipated in Member State concerned | 13 | 
| E.8.5 | The trial involves multiple Member States | Yes | 
| E.8.5.1 | Number of sites anticipated in the EEA | 108 | 
| E.8.6 Trial involving sites outside the EEA | 
| E.8.6.1 | Trial being conducted both within and outside the EEA | Yes | 
| E.8.6.2 | Trial being conducted completely outside of the EEA | No | 
| E.8.6.3 | If E.8.6.1 or E.8.6.2 are Yes, specify the regions in which trial sites are planned | 
| Argentina |  
| Belgium |  
| Brazil |  
| Bulgaria |  
| Canada |  
| Chile |  
| Croatia |  
| Czech Republic |  
| Denmark |  
| Estonia |  
| Finland |  
| France |  
| Germany |  
| Hungary |  
| Ireland |  
| Israel |  
| Italy |  
| Korea, Republic of |  
| Lithuania |  
| Poland |  
| Portugal |  
| Romania |  
| South Africa |  
| Spain |  
| Taiwan |  
| Ukraine |  
| United Kingdom |  
| United States |  | 
| E.8.7 | Trial has a data monitoring committee | Yes | 
| E.8.8 | Definition of the end of the trial and justification where it is not the last
                        visit of the last subject undergoing the trial |  | 
| E.8.9 Initial estimate of the duration of the trial | 
| E.8.9.1 | In the Member State concerned years | 2 | 
| E.8.9.1 | In the Member State concerned months | 9 | 
| E.8.9.1 | In the Member State concerned days | 28 | 
| E.8.9.2 | In all countries concerned by the trial years | 2 | 
| E.8.9.2 | In all countries concerned by the trial months | 9 | 
| E.8.9.2 | In all countries concerned by the trial days | 28 |