INTRODUCTION: Immunoglobulin therapy has been shown to be effective in improving impairment and disability scores for patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), a slow progressing or relapsing immune-mediated neuropathy. Intravenous immunoglobulin (IVIG) is recommended as a first-line therapy option. This study aimed to describe real-world treatment patterns among patients with CIDP initiating IVIG treatment.
METHODS: This retrospective cohort study used health insurance claims data between 2008 and 2018 from the IBM MarketScan Research Databases. Adult patients (≥18 years old) with CIDP without prior immunoglobulin treatment were identified, and patients subsequently initiating IVIG were included in the analysis. We described timing and frequency of dosing, switching to other immunoglobulin treatments, discontinuation of the index IVIG, and initiation of other CIDP treatments.
RESULTS: Of 32,090 immunoglobulin-naïve patients with CIDP identified, 3975 patients initiated IVIG and were included in this analysis. Few patients had previous non-immunoglobulin CIDP therapy, except for high-dose corticosteroids (34%). Patients received a median of 1 IVIG dose (Q1,Q3: 1,3) during the 14-day loading period. After the loading period, the median interim between doses was 21 days (Q1,Q3: 7,28) and median treatment duration was 129 days (Q1,Q3: 85,271). Most (68%) patients arrived at steady-state dose with index IVIG treatment; of those, 27% discontinued the index IVIG and 6% switched immunoglobulin treatment by year 1 of follow-up. Most patients who discontinued did so by the fourth treatment month, and fewer patients discontinued after the eighth treatment month.
CONCLUSIONS: Observed IVIG treatment patterns in immunoglobulin-naïve patients with CIDP were consistent with clinical practice, including treatment frequency and discontinuation patterns. Many patients discontinued treatment by the eighth month; after which less discontinuation occurred. Most patients who initiated IVIG treatment had no prior CIDP treatment.
