Targeted proteomics upon Tofersen identifies candidate response markers for SOD1-linked amyotrophic lateral sclerosis

Abstract

Tofersen is the first effective and approved therapy for familial ALS caused by pathogenic variants in the SOD1 gene. Following treatment with tofersen, neurofilaments in patients CSF and serum display a faster response than clinical parameters, underlining their importance as a biomarker for treatment response in clinical trials. This evidence led us to hypothesize that this novel treatment might represent an opportunity to identify additional therapy-responsive biomarkers for ALS. We chose the commercial NUcleic acid Linked Immuno-Sandwich Assay (NULISA), to investigate a predefined panel of 120 neural, glial and inflammatory markers in CSF and serum samples longitudinally collected from SOD1-ALS patients at baseline and three months after tofersen treatment. We identified a set of proteins (beyond pNfH and NfL) whose levels differed between SOD1-ALS and the matched control group and that were responsive to treatment with tofersen, including Amyloid beta 40;42, NPY and UCHL1. Even though our results warrant validation in larger cohorts and longer follow-up time, they may pave the way for a panel of responsive proteins solidifying biomarker endpoints in clinical trials.