Efficacy of RGn600 in Patients With Mild-to-moderate Alzheimer's Disease

This multicentric investigation is planned to include 108 patients in France who will be followed up to 52 weeks. Patients meeting all eligibility criteria will be randomized on a 1: 1 ratio into one of the two following treatment groups: active RGn600 device or sham device (inactivated RGn600). The site investigation teams and patients/caregivers will be blinded. The device will be applied to the patients during 26 weeks through 20-min onsite sessions following the below pattern: * 5 treatment sessions per week from Week 1 (W1) to W8 * 3 treatment sessions per week from W9 to W16 * 2 treatment sessions per week from W17 to W26 Throughout the investigation, patients will be treated per randomization with the device initially allocated by the IWRS. Follow-up will continue up to W52 ± 2 weeks At inclusion visit, after verification of the eligibility criteria, data regarding patients will be collected: demographic data, date of AD diagnosis, comorbidities, concomitant medications, sociological data. A blood sample for APOE genotyping will be also performed. Endpoints will be evaluated during 4 onsite visits at Day 0 (Inclusion, randomization to the active or sham group and first treatment session), W8 (last treatment session of), W26 (last treatment session of) and W52 ± 2 weeks. During these visits: * Patient's cognition and autonomy will be assessed through neurological scales and/or neuropsychological tests * Patient's quality of life and medico-economic interest of RGn600 treatment with regards to healthcare consumption will be assessed through questionnaires fulfilled by the patient himself/herself with the help of his/her caregiver * The safety of RGn600 will be assessed : collection of all AEs and device deficiencies, blood samples for safety analysis, clinical exams Within the context of this investigation, a biobank will be created based on blood, fecal and saliva samples of patients included by Toulouse University Hospital Gerontopole site: * Blood samples will be collected for all patients included by this site (at D0, W26 and W52) * Fecal samples will be collected for the first 30 consecutive patients included by this site (at D0, W26 and W52). * Saliva samples will be collected for the patients included by this site after the substantial modification approval (at D0, W26 and W52). The biobank will be located at the site. The objective of this biobank will be to perform subsequent analysis on blood samples of AD blood markers. Other analyses might be conducted on blood, fecal and saliva samples as well such as Inflammatory blood markers (iAGE), fecal microbiota and metabolome and salivary micro RiboNucleic Acid (microRNAs)