The current state of biomarker research for Friedreich's ataxia: a report from the 2018 FARA biomarker meeting

Abstract

The 2018 FARA Biomarker Meeting highlighted the current state of development of biomarkers for Friedreich's ataxia. A mass spectroscopy assay to sensitively measure mature frataxin (reduction of which is the root cause of disease) is being developed. Biomarkers to monitor neurological disease progression include imaging, electrophysiological measures and measures of nerve function, which may be measured either in serum and/or through imaging-based technologies. Potential pharmacodynamic biomarkers include metabolic and protein biomarkers and markers of nerve damage. Cardiac imaging and serum biomarkers may reflect cardiac disease progression. Considerable progress has been made in the development of biomarkers for various contexts of use, but further work is needed in terms of larger longitudinal multisite studies, and identification of novel biomarkers for additional use cases.

Keywords: Friedreich’s ataxia; biomarkers; drug development.

Figure 1.. The structure of frataxin protein.

Full-length frataxin (1–210, yellow, gray, cyan, green), intermediate form-1 (42–210, gray, cyan, green), intermediate form-2 (55–210, cyan, green), mature frataxin (81–210, green) and isoform E (76–210, brown). MPP: Mitochondrial processing peptidase, which cleaves at the R-2 sites.

Figure 2.. Role of biomarkers in the development of therapies for Friedreich’s ataxia.

Biomarkers are in development for many different contexts of use in FA. CKC: Corticokinematic coherence; crCEST: Creatine chemical exchange saturation transfer; FARS: Friedreich’s Ataxia Rating Scale; FXN: Frataxin; NFL: Neurofilament light; mRNA: Messenger ribonucleic acid; QST: Quantitative sensory testing; SARA: Scale for assessment and rating of ataxia.