10th Congress of the European Academy of Neurology, Helsinki, Finland, June 29-July 2, 2024
The following summarizes some of the data presented at EAN 2024.
Using sNfL to guide treatment decision-making in MS
IL-6 as a biomarker of CNS inflammation
Targeting IL-6 with tocilizumab
Low relapse risk in NMOSD after meningitis vaccination
Smoking exposure and MS risk
CONGRESS HIGHLIGHTS – THURSDAY EDITION
Using sNfL to guide treatment decision-making in MS
A South American study examined the feasibility of using sNfL measures to monitor treatment response as a guide to therapeutic decision-making (Duarte et al. EAN 2024;EPO-474). The study enrolled 66 MS patients and 24 matched controls. In the subgroup with evidence of disease activity (EDA), the mean NfL level was 30.25 pg/mL. In comparison, in the group with no evidence of disease activity (NEDA), the mean NfL level was 6.65 pg/mL, which was comparable to what was seen in healthy controls (6.67 pg/mL). The mean NfL level was 13.98 pg/mL in untreated patients and 12.94 pg/mL in patients initiating a modest-efficacy DMT. NfL level was significantly lowered (to 6.96 pg/mL) after switching to a higher-efficacy DMT.
A separate study surveyed physicians about using NfL in different clinical contexts (Wessels et al. EAN 2024;EPR-098). Adding NfL to the diagnostic criteria improved clinician’s certainty about the diagnosis; clinical decision-making was altered in 19.3% of cases. A low NfL result reassured clinicians that no new lesions would be found on MRI-brain. Clinicians stated that the urgency in obtaining NfL was greatest in patients reporting new MS symptoms.
IL-6 as a biomarker of CNS inflammation
The pro-inflammatory cytokine interleukin-6 has been implicated in the pathogenesis of neuromyelitis optica spectrum disorder (NMOSD). But the relationship between IL-6 and other inflammatory biomarkers in CSF has not been determined. An Italian study obtained CSF samples from 20 consecutive patients with a suspected CNS inflammatory disorder (Virgilio et al. EAN 2024;EPO-075). IL-6 levels were significantly higher in patients with NMOSD and MOGAD compared to MS (35.25 vs. 4.98 pg/mL). IL-6 levels were higher in patients who were negative for oligoclonal bands (OCBs).
Targeting IL-6 with tocilizumab
Tocilizumab is a monoclonal antibody that targets the IL-6 receptor and has been shown to be effective as an immunosuppressant in rheumatoid arthritis, giant cell arteritis and COVID-19. In the phase II TANGO trial, tocilizumab was superior to azathioprine in reducing the risk of relapse in NMOSD (Zhang et al. Lancet Neurol 2020;19:391-401). A case series now reports that tocilizumab is effective in MOGAD (Virgilio et al. EAN 2024;EPO-383). All patients met the recent diagnostic criteria for MOGAD (Banwell et al. Lancet Neurol 2023;22:268-282). After initial treatment with steroids, all patients received tocilizumab 8 mg/kg q4wk. All patients achieved stability on clinical examination and MRI.
A separate study examined the efficacy of tocilizumab in patients with refractory myasthenia gravis (Chang et al. EAN 2024;EPR- 240). The primary outcome was the mean change from baseline in the MG activities of daily living (MG-ADL) scale. A total of 34 patients were randomized to tocilizumab or conventional immunotherapy. There was a significantly greater reduction in MG-ADL score with tocilizumab by week 4. Tocilizumab-treated patients were able to reduce the dose of prednisone and were more likely to achieve higher functional scores at week 24 than patients receiving conventional treatment.
Low relapse risk in NMOSD after meningitis vaccination
The complement-5 inhibitors eculizumab and ravulizumab have been approved in Canada for the treatment of AQ4+ neuromyelitis optica spectrum disorder (NMOSD). Since complement inhibitors have been associated with Neisseria meningitidis infections, patients must be vaccinated against meningococcal infection prior to initiating treatment. A concern, however, is that vaccination may activate the complement pathway and worsen NMOSD. A U.S. study examined the rate of relapses in the four weeks after vaccination in NMOSD patients (Fam et al. EAN 2024;EPO-776). Data were obtained from the PREVENT trial of eculizumab and the CHAMPION-NMOSD trial of ravulizumab. In PREVENT, 3.1% in the eculizumab group and 10.6% in the placebo group had a relapse. In CHAMPION-NMOSD, the relapse rate was 2.9%. The authors noted that it has not been determined if relapses were attributable to vaccination or to an inherent risk among NMOSD patients.
Smoking exposure and MS risk
The EnvIMS study is a case-control study investigating whether exposure to parental smoking has an impact on the development of MS (Ferri et al. EAN 2024;OPR- 039). The study involved patients from Norway (n=2674), Canada (n=1565) and Italy (n=2040). Maternal smoking during pregnancy (odds ratio 1.38) and past exposure to mother’s second-hand smoke (odds ratio 1.39) were associated with MS in Norway but not in the other two countries. Past exposure to paternal second-hand smoke was not significantly associated with MS in any of the countries examined.