Dimethyl Fumarate Treatment Shifts The Immune Environment Toward An Anti-inflammatory Cell Profile While Maintaining Protective Humoral Immunity
MULTIPLE SCLEROSIS JOURNAL
Longbrake EE, Mao-Draayer Y, Cascione M, Zielinski T, Bame E, Brassat D, Chen C, Kapadia S, Mendoza JP, Miller C, Parks B, Xing D and Robertson D.
Mult Scler. 2020 Jul 27;1352458520937282
Delayed-release dimethyl fumarate (DMF) demonstrates sustained efficacy and safety for relapsing forms of MS. Absolute lymphocyte count (ALC) is reduced initially, then stabilizes on treatment.
PROCLAIM, a 96-week, prospective, open-label, phase 3b study, assessed lymphocyte subsets and immunoglobulin (Ig) levels during 48 and 96 weeks (W) of DMF treatment.
Patients received 240 mg DMF BID. Endpoints: lymphocyte subset count changes (primary); Ig isotypes and ALC changes (secondary); adverse events and relationship between ALC changes and ARR/EDSS (exploratory); and neurofilament assessment (ad hoc).
Of 218 patients enrolled, 158 (72%) completed the study. Median ALC decreased 39% from baseline to W96 (BL–W96), stabilizing above the lower limit of normal (baseline: 1.82 × 109/L; W48: 1.06 × 109/L; W96: 1.05 × 109/L). CD4 + and CD8 + T cells correlated highly with ALC from BL–W96 (p < 0.001). Relative to total T cells, naive CD4 + and CD8 + T cells increased, whereas CD4 + and CD8 + central and effector memory T cells decreased. Total IgA, IgG, IgM, and IgG1–4 subclass levels remained stable. Adverse event rates were similar across ALC subgroups. ARR, EDSS, and neurofilament were not correlated with ALCs.
Lymphocyte decreases with DMF were maintained over treatment, yet immunoglobulins remained stable. No increase in infection incidence was observed in patients with or without lymphopenia.