Drug Repurposing Efforts Target New Patient Populations, Including Neurodegenerative Diseases

Drug repurposing refers to research efforts to expand the therapeutic applications of existing medications, and drug repositioning refers to research efforts into drugs that never made it to market. In neurodegenerative disorders, drug repurposing has emerged as a potentially pragmatic shortcut, allowing earlier entry into mid- to late-stage trials.

Drug repurposing includes applications beyond the intended or approved clinical issue, as well as expanding the target population and changes to route of administration or dosage. A big advantage of these approaches is that preliminary data is already available, including data on the mechanism-of-action, pharmacokinetics, pharmacodynamics, and drug safety and efficacy from clinical trials. These data can be leveraged to inform study design and the identification of patient populations that are most likely to benefit.

Neurodegenerative disorders are complex diseases whose often heterogeneous biology has hampered translation from preclinical promise to clinical benefit. In one review, four repurposing tools are highlighted in the context of four small molecules originally approved for other indications that are now being clinically tested for use in neurodegenerative diseases.

Drug repurposing and repositioning efforts provide a tremendous opportunity to benefit not only a wide variety of common diseases but, critically, also rare diseases. Experimental research ranging from pharmaceutical mechanism-of-action to clinical trials, outcomes and side-effects are all welcome, while screening studies to identify candidate drug-disease combinations will be considered only if they go beyond in silico applications.