Therapeutic tools for familial ALS.

Familial ALS (FALS) accounts for 10 to 15% of ALS cases. In more than 70% of FALS patients, a causal gene is identified and animal models have been developed for a subset of them, mainly for the most frequently mutated genes. Therapeutic tools to treat those patients are dominated by gene-specific therapy and the most advanced approaches target the SOD1 gene mutations. Either by direct delivery of antisense oligonucleotides (ASO) or using viral vectors such as adenoviruses (AAV) to deliver ASOs, gene specific therapies have shown promising results in animal models. The recent use of subpial injections of AAV9+anti SOD1 ASO now shows that the disease is completely prevented or stopped in the animal, depending on the moment of injection, e.g., before or after disease onset. However, the use of viral vectors in humans seems to be limited at least by their immunogenicity. Antibody-based therapies are also efficient to treat animal models, but to a lesser extent. Most of the experiments targeted the SOD1 protein in its misfolded conformation. This approach seems better tolerated than the AAV one, an important limit being the choice of the epitope. Unexpectedly, some advances in treating the C9ORF72 animal model have been obtained using a modulation of microbiota, and this strategy has the great advantage to have an easy route of administration and a good safety profile. The landscape of experimental FALS treatment is rapidly evolving and results are promising. This is an important unmet need for ALS patients and several human phase I, II and III trials are ongoing.

Serum neurofilament light chain at time of diagnosis is an independent prognostic factor of survival in amyotrophic lateral sclerosis.

BACKGROUND AND PURPOSE: The prognostic value of serum neurofilament light chain (sNfL), a biomarker of neurodegeneration, compared to other prognostic factors of amyotrophic lateral sclerosis (ALS) at the time of diagnosis, remains unclear. METHODS: Sera from ALS patients were prospectively collected at the first diagnostic visit in our centre. sNfL levels were determined by single molecule array in 207 ALS patients and in 21 healthy controls. The prognostic value of sNfL was compared with that of other known clinical prognostic factors using a Cox regression model and multivariate analysis. RESULTS: Serum neurofilament light chain levels were higher in ALS patients than in controls (P < 0.0001). Seven parameters were predictive of death in ALS: older age, bulbar onset, higher ALS Functional Rating Scale revised (ALSFRS-R) score, greater weight loss, lower maximal inspiratory pressure, forced vital capacity and higher sNfL levels. A Cox regression model showed that sNfL (P < 0.0001), weight loss (P = 0.040) and site at onset (P = 0.048) were independent predictive factors of death. In a sub-cohort restricted to 139 patients with complete spirometry data, sNfL level (P < 0.005) and forced vital capacity (P = 0.022) were independent factors predictive of death. In a subgroup of 142 patients in whom ALSFRS-R score was available at several time points, sNfL levels positively correlated with ALSFRS-R rate of decline (r = 0.571, P < 10-12 ). CONCLUSIONS: Higher sNfL concentration is a strong and independent prognostic factor of death in ALS as early as the time of diagnosis.