A Study to Evaluate Safety and Tolerability of Different Doses and Efficacy of PQ912 in Subjects With MCI and Mild AD

This is a phase 2B multicenter, randomized, double-blind, placebo-controlled, parallel group dose finding study to evaluate the safety, tolerability and efficacy of PQ912, an inhibitor of the glutaminyl cyclase enzyme, in 250 subjects with mild cognitive impairment and mild dementia due to Alzheimer 's Disease.

In the parallel group dose finding part of the study the first 90 subjects will be randomized 1:1:1 between PQ912 300 mg BID, 600 mg BID, and placebo. When the 90th patient has completed the week 24 treatment visit, the DSMB will decide on the dose of PQ912 to be continued. The decision is based on safety findings only, no efficacy data will be considered. After the DSMB has reached a decision on the dose to be continued, all subjects randomized to receive PQ912 will be reallocated to this dose (1:1). The duration of Subjects participation in the study is either 48, 60, 72, 84 or 96 weeks of treatment (depending on time of randomization). Subjects recruited early into the study will be kept on treatment for 96 weeks or until the regular, scheduled study visit which is closest to the scheduled week 48 visit of the last subject recruited in the study, whichever comes first.