• Time to death
  
• proportion of responders, with "responders" defined as patients showing either clinical improvement or lack of deterioration in 3 key neurological and neuropsychiatric measures
  

• Mini Mental State Examination (MMSE)
  
• Clinician's Dementia rating (CDR)
  
• Rankin score
  
• Alzheimer's Disease Assessment Scale - Cognitive (ADAS-Cog)
  
• Glasgow coma score
  
• Barthel Activities of Daily Living (ADL)
  
• magnetic resonance imaging scan (MRI)
  
• electro-encephalogram (EEG)
  
• cerebrospinal fluid (CSF)
  

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.