A randomized study of H3R antagonist ABT-288 to evaluate its efficacy and safety in subjects with mild-to-moderate AD is prematurely terminated, because ABT-288 dose groups do not significantly differ from placebo group, while the active comparator donepezil demonstrates statistically significant improvement, suggesting ABT-288 shows no efficacy in the symptomatic treatment of AD [120]. This evidence concerns the gene HRH3 and Alzheimer disease.