[Correspondence] Stratifying IL-2 therapy in ALS: integrating biomarkers

In the MIROCALS trial, Gilbert Bensimon and colleagues1 showed that low-dose interleukin-2 (IL-2) added to riluzole did not significantly reduce mortality in an unadjusted analysis of patients with early-stage amyotrophic lateral sclerosis (ALS). However, in patients with low levels of cerebrospinal fluid-phosphorylated neurofilament heavy chain (CSF-pNFH), IL-2 significantly increased regulatory T cells (Tregs) and reduced mortality after covariate adjustment, suggesting a potential benefit in this subgroup.