Abstract
With aging populations in many countries, the prevalence of neurodegenerative diseases is expected to increase in the upcoming decades. Currently, no disease modifying therapies for these conditions exist. Advances in genetics and proteomics have identified novel druggable targets for neurodegenerative diseases. Compounds modulating these targets have recently entered clinical trials. These compounds can be orally administered small drug molecules, intravenously dosed antibodies, intrathecally injected antisense oligonucleotides (ASOs), gene therapies, stem cells or viral vectors. For the development of these compounds to be successful, multiple challenges have to be overcome. In this review we discuss advances in drug development for each of the major neurodegenerative diseases, which, when applied to early phase drug studies, increase the chance of successful clinical development. Here we will limit ourselves to: 1) the use of biomarkers for understanding target and pathway engagement at an early stage of development, 2) novel approaches for increasing blood-brain barrier penetration and 3) advances in understanding cerebrospinal fluid flow dynamics in relation to neurodegeneration and target site distribution for intrathecally administered compounds.