Change in serum neurofilament light chain and glial fibrillary acidic protein levels with high-efficacy and low-efficacy early therapy in multiple sclerosis.

INTRODUCTION

Neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) are associated with multiple sclerosis (MS) outcomes. We compare how high-efficacy early therapy (HEET) and lower-efficacy early therapy (LEET) affect serum NfL and GFAP at the initiation of disease-modifying therapy (DMT) and in the years afterwards.

METHODS

Adults diagnosed with MS within 5 years of symptom onset at our centre were eligible. Records from DMT-naïve patients with serum NfL and GFAP drawn in the year before treatment start and follow-up samples 6-36 months after treatment initiation were included in the 'pre-initiation' cohort. Those with baselines after DMT initiation and follow-up samples within 5 years were included in the 'post-initiation' cohort.

RESULTS

There were 155 pre-initiation patients (HEET: 85, LEET: 70) and 213 post-initiation (HEET: 55, LEET: 158). NfL levels were reduced following DMT initiation but did not differ significantly between HEET and LEET in either cohort. GFAP was not substantially impacted by either HEET or LEET.

CONCLUSION

The difference in NfL reduction with HEET and LEET may be smaller than anticipated, perhaps reflecting that disease activity risk is considered in real-world DMT selection. There is minimal impact of HEET or LEET on GFAP, at least over several years.