Moreover, clinical trials led by Biogen (NCT04288856) or Wave Life Sciences (NCT04931862), each testing distinct investigational antisense oligonucleotides that target GGGGCC repeat transcripts as a treatment for C9orf72-associated ALS/FTD, failed to show clinical benefit in line with increased NfL concentrations [63, 64]. This evidence concerns the gene C9orf72 and frontotemporal dementia.