| E.1 Medical condition or disease under investigation | 
| E.1.1 | Medical condition(s) being investigated | 
| Autism Spectrum Disorder (ASD) |  | 
| E.1.1.1 | Medical condition in easily understood language | 
| Autism Spectrum Disorder (ASD) |  | 
| E.1.1.2 | Therapeutic area | Psychiatry and Psychology [F] - Mental Disorders [F03] | 
| MedDRA Classification | 
| E.1.2 Medical condition or disease under investigation | 
| 
| E.1.2 | Version | 21.1 |  
| E.1.2 | Level | PT |  
| E.1.2 | Classification code | 10063844 |  
| E.1.2 | Term | Autism spectrum disorder |  
| E.1.2 | System Organ Class | 10037175 - Psychiatric disorders |  | 
| 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 | 
| To demonstrate the superiority of bumetanide (0.5mg BID) oral liquid formulation compared to placebo in the improvement of ASD core symptoms after 6 months of treatment in ASD children aged from 2 to less than 7 years old |  | 
| E.2.2 | Secondary objectives of the trial | 
| - To assess the effect of bumetanide on the other efficacy endpoints - To assess the safety of bumetanide
 - To confirm the acceptability and palatability of the oral liquid formulation
 - To describe the bumetanide effects on patients quality of life
 - To improve existing pharmacokinetic model of bumetanide in this population
 
 |  | 
| E.2.3 | Trial contains a sub-study | No | 
| E.3 | Principal inclusion criteria | 
| - Male and female patients from 2 to less than 7 years - Out patients
 - Primary diagnosis of ASD as per DSM-5 criteria
 - Criteria met for ASD on Autism Diagnostic Observation Schedule (ADOS-2) and Autism Diagnosis Interview Revised (ADI-R)
 - CGI (Clinical Global Impression) – Severity rating Score ≥ 4
 - Childhood Autism Rating Scale second edition (CARS2-ST or HF) total
 raw score ≥ 34
 - Social Responsiveness Scale second edition total score (SRS-2 T-Score)  ≥ 66
 - Absence of known monogenic syndrome (Fragile X, Rett syndrome ...)
 - Absence of any clinically significant abnormality likely to interfere with the conduct of the study according to the judgment of the investigator
 - Absence of electrolyte imbalance that is likely to interfere with the study conduct or evaluation
 |  | 
| E.4 | Principal exclusion criteria | 
| - Patients not able to follow the study assessments defined by the protocol, with the exception of self-rating questionnaires which will be assessed by parent/legal representative/caregiver for those patients unable to complete them - Patients having a high suicidal risk according to the investigator judgement
 - Chronic renal dysfunction
 - Chronic cardiac dysfunction
 - Patient with unstable psychotherapy, behavioural, cognitive or cognitive-behavioural therapy
 - Absence of electrolyte imbalance that is likely to interfere with the study conduct or evaluation
 |  | 
| E.5 End points | 
| E.5.1 | Primary end point(s) |  | 
| E.5.1.1 | Timepoint(s) of evaluation of this end point | 
| Change from baseline to 6 month |  | 
| E.5.2 | Secondary end point(s) | 
| - Each individual CARS2 domain, SRS-2 total raw score, CGI-I score, VABS II subscores - Adverse events, Paediatric Adverse Event Rating Scale (PAERS), clinical laboratory evaluation, vital signs and clinical examination, electrocardiogram, renal ultrasound, Columbia Suicide Severity Rating Scale Children's version (C-SSRS-C)
 - Acceptability and palatability questionnaire
 - Paediatric Quality of Life Inventory (PedsQL), WHOQOL-Bref questionnaire
 - PK parameters of bumetanide
 |  | 
| E.5.2.1 | Timepoint(s) of evaluation of this end point | 
| SRS-2 total raw score: W000/W004/W012/W026/W038/W052 CGI-I score: W000+Day17/W004/W008/W012/W016/W020/W026/W038/W052/WEND
 VABS II subscores: W000/W026/W052
 Each individual CARS2 domain: W000/W004/W012/W026/W038/W052/WEND
 Adverse events/PAERS/Clinical laboratory evaluation/Electrolytes monitoring (sodium, potassium)/Clinical examination: all along the study
 Vital signs: ASSE/W000/W00+D17/W012/W026/W026+Day17/W038/W052
 Electrocardiogram: ASSE/W004/W008/W012, W026/W030/W034/W038/W052
 Renal ultrasound: ASSE/W026/W052
 C-SSRS-C: W000/W012/W026/W038/W052
 Acceptability and palatability questionnaire: W026
 PedsQL / WHOQOL-Bref questionnaire: W000/W004/W012/W026/W030/W038/W052 + W008/W034 for WHOQOL-Bref questionnaire
 PK parameters of bumetanide: W012/W026
 |  | 
| 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 | No | 
| E.6.4 | Safety | Yes | 
| E.6.5 | Efficacy | Yes | 
| E.6.6 | Pharmacokinetic | Yes | 
| E.6.7 | Pharmacodynamic | No | 
| E.6.8 | Bioequivalence | No | 
| E.6.9 | Dose response | No | 
| E.6.10 | Pharmacogenetic | No | 
| E.6.11 | Pharmacogenomic | No | 
| E.6.12 | Pharmacoeconomic | No | 
| 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 | Yes | 
| E.8.1.1 | Randomised | Yes | 
| E.8.1.2 | Open | No | 
| E.8.1.3 | Single blind | No | 
| E.8.1.4 | Double blind | Yes | 
| E.8.1.5 | Parallel group | Yes | 
| E.8.1.6 | Cross over | No | 
| E.8.1.7 | Other | Yes | 
| E.8.1.7.1 | Other trial design description | 
| Double-blind treatment period of 6 months followed by an open-label treatment period of 6 months |  | 
| E.8.2 | Comparator of controlled trial | 
| E.8.2.1 | Other medicinal product(s) | No | 
| E.8.2.2 | Placebo | Yes | 
| E.8.2.3 | Other | No | 
| E.8.2.4 | Number of treatment arms in the trial | 2 | 
| 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 | 4 | 
| E.8.5 | The trial involves multiple Member States | Yes | 
| E.8.5.1 | Number of sites anticipated in the EEA | 55 | 
| 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 | 
| Australia |  
| Belgium |  
| Brazil |  
| Czechia |  
| France |  
| Germany |  
| Hungary |  
| Ireland |  
| Italy |  
| Netherlands |  
| Poland |  
| Portugal |  
| Slovakia |  
| Spain |  
| 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 | 
| Last Visit Last Participant as stated in the protocol |  | 
| 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 | 6 | 
| E.8.9.1 | In the Member State concerned days | 0 | 
| E.8.9.2 | In all countries concerned by the trial years | 4 | 
| E.8.9.2 | In all countries concerned by the trial months | 3 | 
| E.8.9.2 | In all countries concerned by the trial days | 0 |