Riluzole does not improve lifespan or motor function in three ALS mouse models

Background: Riluzole is the most widespread therapeutic for treatment of the progressive degenerative disease amyotrophic lateral sclerosis (ALS). Riluzole gained FDA approval in 1995 before the development of ALS mouse models. We assessed riluzole in three transgenic ALS mouse models: the SOD1^G93A model, the TDP-43^A315T model, and the recently developed FUS (1-359) model. Methods: Age, sex and litter-matched mice were treated with riluzole (22 mg/kg) in drinking water or vehicle (DMSO) from symptom onset. Lifespan was assessed and motor function tests were carried out twice weekly to determine whether riluzole slowed disease progression. Results: Riluzole treatment had no significant benefit on lifespan in any of the ALS mouse models tested. Riluzole had no significant impact on decline in motor performance in the FUS (1-359) and SOD1^G93A transgenic mice as assessed by Rotarod and stride length analysis. Conclusions: Riluzole is widely prescribed for ALS patients despite questions surrounding its efficacy. Our data suggest that if riluzole was identified as a therapeutic candidate today it would not progress past pre-clinical assessment. This raises questions about the standards used in pre-clinical assessment of therapeutic candidates for the treatment of ALS.