Efficacy Study of a ZT-1 Implant in Patients Suffering From Alzheimer's Disease

This is a multicenter, randomised, double-blind, double-dummy, oral donepezil controlled study on the safety and efficacy of repeated monthly s.c. injections of a sustained-release implant of ZT 1 in patients with moderate Alzheimer's Disease. The study enrolls patients aged \>50 years, with moderate AD with a MMSE score at study screening ≥14 and ≤22. The study aims to recruit 128 patients. The study is divided into 3 periods: 1. A screening period 2. A 6-month treatment period, consisting of one month of titration with an oral medication and 5 months of treatment with an implant administered under the skin every 4 weeks. Oral treatment will be maintained throughout the treatment phase 3. A 2 week follow-up period. Patients will be randomized in a 1:1 ratio to one of 2 groups: the ZT-1 (investigational product) treatment group or the donepezil (active comparator) treatment group. The study comprises a total of 11 visits including screening and follow-up. An additional visit for PK/PD assessment is scheduled in about 10% of patients.