PARIS—It is possible to gauge the effects of disease-modifying therapies (DMTs) for multiple sclerosis (MS) by measuring serum levels of neurofilament light (NFL), according to research presented at the Seventh Joint ECTRIMS–ACTRIMS Meeting. DMTs with greater efficacy appear to be associated with lower serum NFL concentrations.
NFL is a biomarker of axonal damage that has been measured primarily in CSF. In patients with MS, the CSF NFL concentration reflects disease activity and the efficacy of DMTs. Investigators recently developed an ultrasensitive immunoassay that can determine NFL levels in serum.
Lenka Nováková, MD
The investigators measured serum NFL concentrations using an in-house ultrasensitive single molecule array immunoassay. The intra-assay and inter-assay coefficient of variation was less than 10%.
Median serum NFL concentration decreased significantly in treatment-naïve patients who initiated second-line DMTs (ie, from 22.7 ng/L to 18.5 ng/L) or escalated from a first-line to a second-line DMT (ie, from 17.9 ng/L to 12.6 ng/L). The median serum NFL concentration was stable in patients who switched between second-line DMTs (14.9 ng/L before the switch and 13.7 ng/L after the switch). Similarly, the median serum NFL concentration did not change significantly in patients who stayed untreated (40.7 ng/L at first measurement and 37.1 ng/L at second measurement), initiated first-line treatment (20.6 ng/L vs 25.5 ng/L), or switched between first-line DMTs (17.3 ng/L vs 16.7 ng/L).
“The goal of DMTs in MS is to reduce axonal degeneration,” said Dr. Nováková. “Repeated analysis of serum NFL may represent a new possibility to monitor this process and may provide objective support in treatment decisions.”