There is currently no effective therapy available for Creutzfeldt-Jakob disease and related prion disorders. However, a limited number of drugs have been found to affect the course of experimental prion diseases and to modify the kinetics of abnormal prion protein accumulation in the CNS. These include polyanions, the amyloid-binding dye Congo red, amphotericin B and its derivatives and, more recently, anthracyclines. At present, the most promising agent appears to be the amphotericin B derivative MS-8209. As a result of its wide spectrum of anti scrapie activity and efficacy in early and late stages of the incubation period of the disease in experimental prion models, MS-8209 could be used as a pharmacological tool to contribute to our understanding of the pathogenic mechanisms involved in these neurodegenerative disorders and to afford a new and valuable base for future therapeutic strategies.