PRION-1 aims to assess the activity and safety of Quinacrine (Mepacrine hydrochloride) in human prion disease. It also aims to establish an appropriate framework for the clinical assessment of therapeutic options for human prion disease that can be refined or expanded in the future, as new agents become available.

The human prion diseases have been traditionally classified into Creutzfeldt-Jakob disease (CJD), Gerstmann-Sträussler-Scheinker (GSS) disease and kuru. They can alternatively be classified into three causal categories: sporadic, acquired and inherited. The appearance of a new human prion disease, variant CJD (vCJD), in the United Kingdom from 1995 onwards, and the experimental evidence that this is caused by the same prion strain as that causing bovine spongiform encephalopathy (BSE) in cattle, has raised the possibility that a major epidemic of vCJD will occur in the United Kingdom and other countries as a result of dietary or other exposure to BSE prions. These concerns have led to intensified efforts to develop therapeutic interventions.

Quinacrine has been previously used to treat other diseases such as malaria; however, it was found to have serious side effects and is no longer licensed in the United Kingdom. There is only very limited evidence from laboratory tests for the potential use of quinacrine in human prion disease, and the evidence to date for any possible clinical benefit is very scarce. The PRION-1 trial is being undertaken since there are no other drugs currently available which are considered suitable for human evaluation.

Inclusion Criteria:

• Aged 12 years or more, diagnosed with any type of human prion disease.

Exclusion Criteria:

• In a coma, or in a pre-terminal phase of disease such that prolongation of the current quality of life would not be supported
• Known sensitivity to quinacrine
• Been taking any other putative anti-prion therapy for less than 8 weeks