Real-world prognostic role of riluzole use in ALS: a multi-center study from PRECISION-ALS

Background: Amyotrophic Lateral Sclerosis (ALS) remains an incurable disease, with limited treatment options, and riluzole is the most widely available drug. We evaluated survival in a large cohort of patients with ALS, comparing those treated with riluzole to those who were not. Methods: Using data from the PRECISION-ALS database, we retrospectively analyzed patients with ALS who were treated with 100 mg of riluzole daily at the time of diagnosis. ALSFRS-R slope from onset to diagnosis (ΔFRS) was calculated. Based on the ΔFRS distribution, we defined fast progressors as patients having a ΔFRS > 1.17, intermediate progressors as those with 1.17 > ΔFRS > 0.31 and slow progressors as those with a ΔFRS < 0.31 points per month. We used Kaplan-Meier curves and Cox proportional hazards model to explore the association of riluzole use with patient survival since diagnosis. Results: Out of the 5842 patients with available riluzole data, 4847 (82.9%) received riluzole. The overall survival significantly differed between patients treated and not treated with riluzole (HR 0.70, 95%CI 0.69, 0.79), independently of sex, site of onset, age at onset and diagnostic delay. Patients treated with riluzole exhibited a 7 month longer median survival than those who did not receive riluzole (17.6 months, IQR 9.7, 29.9 vs 10.7 months, IQR 4.3, 23.4; p = 2 × 10−16). The relationship between riluzole use and extended survival varied across ΔFRS strata, being only evident among fast progressors (HR = 0.50, 95% 0.40, 0.63). Conclusions: Treatment with riluzole is an independent prognostic factor in ALS. The extended survival related to riluzole use was only evident among fast-progressing patients.