RT Journal Article SR Electronic T1 Characterizing absolute lymphocyte count profiles in dimethyl fumarate–treated patients with MS JF Neurology: Clinical Practice FD Lippincott Williams & Wilkins SP 220 OP 229 DO 10.1212/CPJ.0000000000000238 VO 6 IS 3 A1 Robert J. Fox A1 Andrew Chan A1 Ralf Gold A1 J. Theodore Phillips A1 Krzysztof Selmaj A1 Ih Chang A1 Mark Novas A1 Jitesh Rana A1 Jing L. Marantz YR 2016 UL http://cp.neurology.org/content/6/3/220.abstract AB Background: Delayed-release dimethyl fumarate (DMF), indicated for the treatment of patients with relapsing-remitting multiple sclerosis (MS), is a disease-modifying therapy with potential immunomodulatory and neuroprotective effects. In clinical trials, DMF was associated with reduced white blood cell and absolute lymphocyte counts. Current US prescribing information recommends obtaining a complete blood count, including absolute lymphocyte count (ALC), before initiating and during DMF treatment.Methods: We conducted an integrated analysis of phase 2b/3/long-term extension studies of DMF in MS (N = 2,470) to characterize ALC profiles.Results: Mean ALCs decreased by 30% during the first year and then plateaued, remaining above the lower limit of normal (LLN). Among patients treated ≥6 months (N = 2,099), 2.2% experienced ALCs <500 mm3 persisting ≥6 months. ALCs remained ≥LLN in 84% and 76% of patients during the first 6 and 12 months, respectively; of these, 0.1% and 0%, respectively, developed ALCs <500 mm3 persisting ≥6 months at any time. Evidence of ALC improvement following DMF discontinuation was observed. DMF efficacy was not substantially different in patients with and without lymphopenia.Conclusion: Lymphocyte monitoring provides effective means for early identification of patients at risk for developing severe, prolonged lymphopenia.