CASi-APOE

CASi-APOE is a conditionally activated small interfering RNA (siRNA) therapy developed by Switch Therapeutics. It is designed to selectively knock down the expression of apolipoprotein E (APOE) in the central nervous system (CNS), specifically targeting APOE4, a major genetic risk factor for Alzheimer’s disease. The drug leverages Switch Therapeutics’ Conditionally Activated siRNA (CASi) platform, which integrates nucleic acid nanotechnology with RNA interference (RNAi). Each CASi molecule contains an siRNA and a sensor strand that docks to unique RNA sequences in target cells, enabling cell-selective activation and gene silencing only in desired tissues. This approach allows for efficient self-delivery, potent and sustained gene knockdown, and improved safety by sparing APOE activity in the liver—where it is essential for lipid homeostasis—while reducing its expression in the brain. Preclinical studies suggest that CNS-specific reduction of APOE may lower amyloid-beta and tau levels, two key pathological hallmarks of Alzheimer’s disease[1][2][3][5].