Early treatment of multiple sclerosis (MS) provides significant long-term benefits. The aim of the Phase IIIb ENSEMBLE study (NCT03085810) is to evaluate the effectiveness and safety of ocrelizumab (OCR) in patients with early-stage relapsing-remitting MS (RRMS). Neurofilament light chain (NfL) is a marker of neuroaxonal injury. OCR reduced elevated NfL levels in patients with relapsing MS and primary progressive MS to those of healthy donors in the OPERA and ORATORIO studies over 96 weeks. NfL levels are assessed yearly in ENSEMBLE.
To report 1-year NfL analyses from ENSEMBLE.
Treatment-naive patients with a diagnosis of early-stage RRMS (age, 18–55 years inclusive; Expanded Disability Status Scale [EDSS] score ≤3.5) per 2010 revised McDonald criteria and a disease duration from the first documented clinical attack consistent with MS disease of ≤3 years and ≥1 clinically reported relapse or ≥1 sign of MRI activity within 12 months of enrollment were included. Patients will receive OCR 600 mg every 24 weeks (first dose, 2×300 mg separated by 14 days) for the 192-week treatment period (maximum 8 doses). Serum NfL levels are measured via the Simoa Quanterix Advantage kit.
A total of 582 patients were included in the NfL evaluation (female, 64.3%; mean [SD]: age, 32.4 [9.2] years; baseline EDSS, 1.70 [0.96]; time since MS symptom onset, 1.08 [0.84] years) with characteristics comparable with the overall population (N=678). The median serum NfL level at baseline was 13.20 pg/mL; 81.8% of patients had levels greater than healthy donors (HDs; 7.1 pg/mL). Median NfL levels at baseline in patients stratified by age, gender and EDSS score were consistent with those of the overall population. The highest median NfL levels at baseline were observed in patients with T1-weighted contrast-enhancing lesions (CELs) at screening (18.71 pg/mL; n=260) and relapses within 3 months of enrollment (14.91 pg/mL; n=217). At Week 48 the median serum NfL level was reduced to 6.35 pg/mL; 60.8% of patients had levels comparable to or lower than the HD level. Decreases in median serum NfL levels were observed, independent of the baseline demographics and disease characteristics of age, gender, EDSS score, CELs, relapses and reason for enrollment.
NfL levels at baseline and patterns of change over 48 weeks were in line with previous evaluations and decreased considerably after 1 year of treatment with ocrelizumab.