Abstract
INTRODUCTION: While clinical trials have established the efficacy of immunoglobulin (Ig) to treat chronic inflammatory demyelinating polyneuropathy (CIDP), real-world data are limited. This study evaluated real-world effectiveness of Ig among patients with CIDP in terms of progressive use of assistive devices as a proxy for deteriorating clinical disability. METHODS: Adults diagnosed with CIDP by a neurologist from 1/2015 to 11/2021 and with a documented nerve conduction study were identified using linked medical and pharmacy claims and electronic medical record (EMR) data in the United States (US). Patients receiving Ig were propensity score matched to patients without Ig. Claims for assistive devices were used as a proxy for disability and assessed over 6-month baseline and follow-up periods. Deterioration was defined as ≥ 1 post-index claim for an assistive device indicating a higher level of disability than observed at baseline. Changes in anticonvulsant, antidepressant, and opioid use were assessed as secondary outcomes. RESULTS: The study sample comprised 1302 Ig-treated and non-Ig-treated matched pairs (mean age 61 years and ~ 40% female). Approximately 40% fewer Ig-treated patients had ≥ 1 level of deterioration (3.3% vs. 5.4%, p = 0.0104) and ≥ 2 levels of deterioration (3.1% vs. 5.1%, p = 0.0079) in assistive device use. Anticonvulsant (48.0-44.8%) and opioid use (39.2-33.3%; both p < 0.0001) decreased from baseline to follow-up in Ig-treated patients but remained unchanged for non-Ig-treated patients. Among patients with baseline opioid use, a higher proportion of Ig-treated patients had opioid improvement over the post-index period (41.5% vs. 32.1%, p = 0.0021). CONCLUSION: Our findings support the effectiveness of Ig therapy in CIDP. The benefits of Ig seen in clinical trials of maintained or improved disability scores appear to be reflected in the real world by less deterioration in assistive device use and lesser use of anticonvulsants, antidepressants, and opioids.