Characteristics of Real-world Patients With Chronic Inflammatory Demyelinating Polyradiculoneuropathy Initiating Subcutaneous Efgartigimod in United States
Swapna Karkare1, Nadia Zaveri1, Arash Mahajerin1, Challa Yachendra2, Wanling Zou2, Mai Sato2, Cecile Blein3
1argenx US, 2ZS Associates, 3argenx BVBA
Objective:

To evaluate characteristics of patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) initiating subcutaneous efgartigimod (SC-EFG).

Background:

Since June 2024 approval of SC-EFG for treatment of adults with CIDP in the United States (US), evidence is still limited around how SC-EFG is utilized within the CIDP treatment paradigm. A preliminary real-world study in early 2025 described early SC-EFG initiators; this is an updated analysis as of August 2025.

Design/Methods:

Adults with CIDP who initiated SC-EFG were identified from US medical and pharmacy claims (based on information licensed from IQVIA: Longitudinal Access and Adjudication Data [LAAD] for the period May 2018 – August 2025, reflecting estimates of real-world activity [all rights reserved]). Adults initiating SC-EFG between 06/21/2024 and 08/31/2025 with a CIDP diagnosis (and no myasthenia gravis diagnosis) within 1 year before SC-EFG initiation were selected (first SC-EFG claim as index). Eligible patients had ≥1 year of quarterly claims activity before index. Patient demographics and CIDP treatment utilization were assessed in the 1 year before index.

Results:
1,258 patients initiating SC-EFG for CIDP were identified. Mean age was 64 years, 62% were male. 25% of patients initiating SC-EFG received no CIDP treatments in 1 year pre-index. Among the 75% (n=940) patients who received any CIDP treatment in 1 year pre-index, 68% (n=636) received immunoglobulins and 64% (n=606) received corticosteroids. Neuropathic pain was documented in 90% of cases. The mean Charlson Comorbidity Index was 1.47.  Frequent medical comorbidities included hypercholesterolemia (34%) and hypertension (32%).   
Conclusions:

Majority of SC-EFG initiators with CIDP had neuropathic pain and prior exposure to CIDP therapies, reflecting high disease burden. Yet, a substantial subset had not received any CIDP treatment in the preceding year, highlighting the potential role of SC-EFG in addressing both treated and undertreated patient populations.

10.1212/WNL.0000000000215680
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