PBT-3

PBT-3 is a small molecule belonging to the 8-hydroxyquinoline chemical class, originally developed by **Alterity Therapeutics** (formerly known as Prana Biotechnology). It is classified as a **Metal-Protein Attenuating Compound (MPAC)**. The drug was designed to treat neurodegenerative diseases by modulating the interaction between transition metals—specifically copper and zinc—and amyloidogenic proteins such as amyloid-beta and alpha-synuclein. In the context of nervous system diseases like Alzheimer's and Parkinson's, these metals can promote protein misfolding, aggregation, and the production of neurotoxic reactive oxygen species. PBT-3 acts as a metal chaperone or ionophore, redistributing these metals from extracellular aggregates back into the neurons, thereby reducing plaque formation and restoring metal homeostasis. While PBT-3 served as an early lead in the MPAC library, it was largely superseded in clinical development by second-generation compounds like PBT2 and the current lead candidate, ATH434 (PBT434).