Intravenous Immunoglobulin Initiation in Patients with Chronic Inflammatory Demyelinating Polyradiculoneuropathy: A US Claims-based Cohort Study

Abstract

Introduction: Intravenous immunoglobulin (IVIG) is recommended as first-line therapy for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), an immune-mediated neuropathy. The clinical profile of patients with CIDP newly initiating IVIG is poorly characterized. This claims-based cohort study describes characteristics of US patients with CIDP initiating IVIG treatment. Methods: Adult immunoglobulin (IG)-naïve patients with CIDP diagnosed between 2008 and 2018 and a subgroup of patients subsequently initiating IVIG were identified in the Merative MarketScan Research Databases. Demographics, clinical characteristics, and diagnostic procedures were described for patients initiating IVIG. Results: Of 32,090 patients with CIDP identified, 3975 (mean age 57 years) subsequently initiated IVIG. In the 6 months prior to IVIG initiation, diagnoses of comorbidities including neuropathy (75%), hypertension (62%), and diabetes (33%) were frequent, as were CIDP features/symptoms/markers of functional status including chronic pain (80%), difficulty walking (30%), and weakness (30%). CIDP-related laboratory/diagnostic procedures were performed in approximately 20– > 40% of patients in the 3 months prior to IVIG initiation (63.7% underwent electrodiagnostic/nerve conduction testing in the 6 months prior to IVIG initiation). Patient characteristics by initial IVIG product differed only in IVIG initiation year, US geographic region, and insurance type. Comorbidities, CIDP severity or functional status markers, and other clinical variables were generally well balanced across initial IVIG product groups. Conclusion: A heavy burden of symptoms, comorbidities, and diagnostic testing exists in patients with CIDP initiating IVIG. Characteristics of patients with CIDP initiating different IVIG products are well balanced, suggesting an absence of clinical or demographic determinants underlying IVIG selection.