INTRODUCTION: Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a rare, immune-mediated neuropathy, and intravenous immunoglobulin (IVIG) is a first-line therapy option. We examined real-world practices with IVIG, including ramp-up, dosing patterns, switching, discontinuation, and add-on therapy. We describe treatment patterns among patients with CIDP initiating IVIG treatment.
METHODS: Adults with CIDP without prior immunoglobulin treatment were identified in MarketScan® insurance database between 2008-2018. Patients subsequently initiating IVIG were identified. Data on timing and frequency of dosing, switching to other immunoglobulin treatments, discontinuation of the index IVIG and initiation of other CIDP treatments were described.
RESULTS: A total of 32,090 immunoglobulin-naïve patients with CIDP were identified; 3,975 initiated IVIG. Few patients had previous non-immunoglobulin CIDP therapy, except for high-dose corticosteroids (34%). Median number of doses during 14-day ramp-up was 1 (interquartile range [IQR] 1-3). After ramp-up, the median interim between doses was 21 days (IQR 7-28) and median treatment duration 129 days (IQR 85-271). At year one of follow up a higher proportion (27%) of patients discontinued the index IVIG compared with those who switched immunoglobulin treatment (6%). Most patients who discontinued did so by the fourth treatment month; 45% of patients initiated another non-IG CIDP treatment after IVIG initiation.
CONCLUSION: Most patients that initiated IVIG treatment did not have prior CIDP treatment. IVIG is typically administered at an interval of 1 to 4 weeks. Many patients discontinued treatment by the eighth dose; after which less discontinuation happens, which is consistent with rates in the literature.
