Our study took an innovative approach by evaluating, in vivo, the efficacy of intranasal (IN) administration of liposomal formulations of donepezil, memantine, and beta-site amyloid precursor protein-cleaving enzyme (BACE-1) siRNA, and their combination as a “triple-drug therapy” in treating Alzheimer’s disease (AD). The gene discussed is BACE1; the disease is early-onset autosomal dominant Alzheimer disease.