…fying therapy. Data were collected in the period 2008 to 2022 and aquaporin-4 (AQP4-IgG) antibody testing may not have been available or routinely used during part of the observation period. sNfL after menopause Serum neurofilament-light chain levels appear to increase after menopause, according to a UCSF longitudinal study of 186 postmenopausal women with MS (Silverman et al. AAN 2023; S9.009). Median age at menopause was 52 years; median duratio…

…;P1.011). Lower NfL levels were associated with better MRI and clinical outcomes. Comparing BTK inhibitors: A pharmacologic study compared the effects of three BTK inhibitors (tolebrutinib, evobrutinib, fenebrutinib) in the CNS in non-human primates (Turner et al. AAN 2023;S46.007). The three drugs achieved similar levels in the CSF after a single oral dose. However, only tolebrutinib CSF exposure exceeded the 90% inhibitory concentration (IC90);…

…ed in 2020/2021 vs. 26-30% pre-pandemic (https://www.cdc.gov/flu/season/faq-flu-season-2020-2021.htm). The same does not appear to be the case for JC virus transmission. An analysis of the TOUCH database (N=22,375) found that during the period of masking and social distancing (2020 to 2022), anti-JCV antibody serostatus changed in about 7.2% of Tysabri patients (Krieger et al. AAN 2023;P12.007). This was comparable to the rate seen prior to the pa…