Serum neurofilament light levels in natalizumab-treated patients with multiple sclerosis who switch to extended interval dosing from every-4-week dosing in real-world clinical practice

Background:Serum levels of neurofilament light chain (sNfL) are a potentially useful biomarker for assessing the efficacy of multiple sclerosis (MS) treatments. Objective:To compare levels of sNfL in patients with MS who switched from natalizumab every 4 weeks (Q4W) to extended interval dosing (EID) and patients who remained on Q4W dosing in real-world clinical practice. Methods:This was a retrospective analysis of samples from patients treated with natalizumab from 2010 to 2015 at a single center in the United States. Levels of sNfL were compared in patients who stayed on Q4W dosing or who switched to EID (parallel-arm analyses) and during Q4W and EID periods in patients who switched to EID (pre- and post-switch analyses). Results:The analysis included 139 patients (Q4W: n = 79; EID: n = 60). After adjustment, levels of sNfL did not significantly differ between patients who remained on Q4W dosing and those who switched to EID in parallel-arm analyses (adjusted Q4W-EID difference = 0.51 pg/mL; p = 0.60) or pre- and post-switch analyses (adjusted difference = 0.96 pg/mL; p = 0.10). Conclusion:These sNfL biomarker results suggest that the effectiveness of natalizumab is maintained in patients who switch from Q4W dosing to EID.

Automated summary

This study aimed to compare levels of sNfL in patients with MS who switched from natalizumab every 4 weeks (Q4W) to extended interval dosing (EID) and patients who remained on Q4W dosing. The results showed no significant difference in sNfL levels between patients who switched to EID and those who stayed on Q4W dosing, suggesting that the effectiveness of natalizumab is maintained in patients who switch to EID.