Alterity Therapeutics Limited is an Australian company that researches and develops therapeutic drugs to treat neurological disorders such as Alzheimer's, Parkinson's, and Huntington's disease. Its lead drug candidate is ATH434, which has completed Phase I clinical trials to treat Parkinson's disease. Alterity Therapeutics Limited was originally known as Prana Biotechnology Limited and is based in Melbourne, Australia, having been incorporated in 1997.