Extension to a Pivotal Study of Sensory Stimulation in Alzheimer's Disease (OLE Hope Study, CA-0015)

This is an open-label extension for a multicenter, randomized, double-blind, sham-controlled, adaptive design pivotal study. Participants who complete the Hope Study (CA-0011) will be eligible to consent for screening to enroll in the OLE Hope Study (CA-0015). All participants will be treated with an Active Sensory Stimulation System (GS120) for 60 minutes daily for up to 12 months. There will be no Sham treatment group or randomization involved in this study. Up to approximately 402 participants will complete the Hope Study and be offered participation in the OLE Hope Study at up to approximately 70 clinical sites. The objective of the study will be to assess efficacy of gamma sensory stimulation (visual and audio) in slowing disease progression in the Active-Active group versus Active-Sham group for subjects with mild to moderate AD as measured functionally by the Alzheimer's Disease Cooperative Study - Activities of Daily Living (ADCS-ADL) assessment and a combined statistical test (CST) for ADCS-ADL and the Mini-Mental State Exam (MMSE). Participants will be treated with the Sensory Stimulation System (GS120) for 60 minutes daily for up to 12 months with Active device settings. Each participant will be involved in the study for up to 13 months: approximately 12 months of treatment and 1 month of safety follow-up.The visits in the study include: a Screening/Enrollment visit (Day 0), followed by telephone training on device receipt, a clinic visit at 12 months and a telephone visit at 6 and 13 months.