INTRODUCTION: Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a rare, immune-mediated neuropathy, and IVIg is a first-line therapy option.
OBJECTIVE: To examine real-world practices with IVIg, including ramp-up, dosing patterns, switching, discontinuation, and add-on therapy. We describe treatment patterns among CIDP patients initiating IVIg treatment.
METHODS: Adults with CIDP without prior immunoglobulin treatment were identified in the MarketScan® insurance database between 2008-2018. Patients subsequently initiating IVIg were identified. Timing and frequency of dosing, switching to other immunoglobulin treatments, discontinuation of the index IVIg, and initiation of other CIDP treatments were described.
RESULTS: Of 32,090 Ig-naïve patients with CIDP identified, 3975 initiated IVIg. Few patients had previous non-Ig 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 was 129 days (IQR 85-271). At year 1 of followup, a higher proportion (27%) of patients discontinued the index IVIg compared with those who switched Ig 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.
SUMMARY/CONCLUSION: Most patients who initiated IVIg treatment did not have prior CIDP treatment. IVIg is typically administered every 1-4 weeks. Many patients discontinued treatment by the eighth month; after which less discontinuation happens, which is consistent with rates in the literature.
