Cracking a New Era of Therapeutic Development in ALS.

Recent advances in genetics, RNA biology, disease modeling, biomarkers, and clinical trial methodology have fundamentally transformed therapeutic development in amyotrophic lateral sclerosis (ALS). Recent clinical successes, including edaravone, ultrahigh-dose methylcobalamin, and antisense oligonucleotide (ASO) therapies such as tofersen, have demonstrated that therapeutic success depends not only on effective drugs but also on improved therapeutic development strategies. These advances have highlighted several fundamental principles, including patient enrichment, intervention during appropriate therapeutic windows, biomarker-guided drug development, and innovative clinical trial design. At the biological level, human genetics and molecular neuropathology have revealed that genetically diverse forms of ALS converge on a limited number of shared pathogenic pathways. In particular, TDP-43 proteinopathy has emerged as the central molecular hallmark of ALS, linking protein aggregation, RNA dysregulation, and neuronal dysfunction. The discovery of TDP-43-dependent cryptic splicing has transformed RNA dysregulation into a therapeutically actionable target and accelerated the development of RNA-targeted therapeutics and mechanism-based biomarkers. In parallel, patient-derived induced pluripotent stem cell (iPSC) models, multi-omics technologies, and computational approaches have fundamentally altered therapeutic discovery and target validation. Furthermore, neurofilament biomarkers, adaptive platform trials, and digital technologies are reshaping clinical evaluation and accelerating therapeutic development. In this review, we discuss how advances in genetics, RNA biology, disease modeling, biomarkers, and clinical trial methodology are collectively redefining therapeutic development in ALS and shaping the next generation of precision medicine for neurodegenerative diseases.