Objective:

To explore the potential utility of serum neurofilament light chain (NFL) as inclusion criteria for clinical trials in patients with amyotrophic lateral sclerosis (ALS). 

Background:

ALS is a rapidly progressive neurodegenerative disease, historically lacking insightful biomarkers to evaluate disease progression. NFL is released with axonal damage; in ALS, studies suggest that serum NFL correlates with disease progression and survival, may serve as a biomarker to monitor therapeutic effects, and should be considered as eligibility criteria in clinical trials. In the clinical setting, however, the use of NFL as a prognostic biomarker is still unclear. We describe utilizing NFL as a predictor of ALS disease progression in clinical practice and evaluate its potential utility as inclusion criteria for clinical trials.

Design/Methods:

This is a retrospective study of a cohort of ALS patients at UC-Irvine neuromuscular clinic. We are obtaining baseline and follow-up serum NFL levels to correlate with demographics (age, gender, disease duration, site of symptom onset) and disease progression measured by ALS functional rating scale (ALSFRS), forced vital capacity, and survival.

Results:

Data collection is ongoing with full statistical analysis to follow. Thus far, 27 patients have been evaluated. Patients with longer disease duration (greater than 36 months) had an average NFL of 32.5 whereas patients with shorter disease duration had average NFL of 98.3. The correlation coefficient between ALSFRS and NFL was –0.02.

Conclusions:

While there has been consideration of using NFL as a potential inclusion criterion in clinical trials, the preliminary data in this cohort suggests a lack of correlation between NFL and disease severity but does suggest that patients with longer disease duration have lower average NFL levels. We plan to collect further longitudinal data and evaluate more patients to assess the potential utility of NFL as clinical trial eligibility criteria in ALS patients.