Anderson-Smits C, Layton JB, Ritchey ME, Hayden V, Chavan S, Souayah N. Patient and treatment characteristics of a large US sample of patients with Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP) Initiating Intravenous Immunoglobulin (IVIG) therapy. Poster presented at the American Academy of Neurology (AAN) 2021 Virtual Annual Meeting; April 17, 2021. Previously presented at the 2020 Muscle Study Group (MSG) Annual Virtual Meeting.

OBJECTIVE: We aimed to identify and describe demographic and clinical characteristics of patients with CIDP in the US initiating IVIG treatment.

BACKGROUND: IVIG is first-line therapy for CIDP, a rare immune-mediated neuropathy. The clinical profile of patients with CIDP newly initiating IVIG is not well characterized.

DESIGN/METHODS: This claims-based cohort study identified immunoglobulin-naïve adults with CIDP from 2008–2018 via diagnosis coding using the IBM® MarketScan® Research Databases. Within the full CIDP cohort, patients who subsequently initiated IVIG therapy were identified. Clinical and demographic characteristics of these new IVIG users were described overall and by initial IVIG product.

RESULTS: Demographics were similar between new IVIG users (n=3975) and the full CIDP cohort (N=32 090). However, new IVIG users versus the full CIDP cohort tended to have greater comorbidity and symptom burdens, which included weakness (31% vs 17%), difficulty walking (30% vs 18%), neuropathic/chronic pain (80% vs 64%), diabetes (33% vs 29%), hypertension (62% vs 52%), hypothyroidism (22% vs 18%), rheumatoid arthritis (19% vs 14%), and other autoimmunity disorders (7% vs 3%), respectively. Median age of new IVIG users was 58 years, 59% were male. Almost all new IVIG use (99%) was started in an ambulatory setting; 35% new IVIG users had prior treatment with high-dose corticosteroids. New IVIG users were more likely than full CIDP cohort to have had an electrodiagnostic/nerve conduction testing, magnetic resonance imaging, or computed tomography. Clinical and demographic characteristics were similar among patients by initial IVIG product, except for US region and calendar year of index treatment.

CONCLUSIONS: There was a trend to initiate IVIG in patients with CIDP who had greater comorbidity and symptom burdens. No correlation was observed between patient characteristics and selection of initial IVIG treatment; rather, differences in selection varied by year and region. Baxalta US Inc. (a Takeda company) funded this study and writing support.