A Study to Assess Adults With CIDP Transitioning From IVIg to Efgartigimod PH20 SC

A Phase 4, Open-Label, Single-Group, Multicenter Study in Adult Participants With Chronic Inflammatory Demyelinating Polyneuropathy Who Transition From Treatment With Intravenous Immunoglobulin to Efgartigimod PH20 SC

This study will measure how adults with CIDP receiving IVIg treatment adjust to efgartigimod PH20 SC. The study duration for each participant will be approximately 17 to 19 weeks.

Study Overview

• Status: Completed
• Conditions: Chronic Inflammatory Demyelinating Polyneuropathy
• Intervention / Treatment: Biological: Efgartigimod PH20 SC

• Study Type: Interventional
• Enrollment (Actual): 23
• Phase: Phase 4

Contacts and Locations

Study Locations

• United States
  • District of Columbia
    • Washington D.C., District of Columbia, United States, 20010
      • Medstar Washington Hospital Center
  • Florida
    • Maitland, Florida, United States, 32751
      • Neurology Associates PA
    • Miami, Florida, United States, 33180
      • Visionary Investigators Network
  • Illinois
    • Chicago, Illinois, United States, 60611
      • Northwestern Memorial Hospital
  • Louisiana
    • Lafayette, Louisiana, United States, 70508
      • Velocity Clinical Research
  • Michigan
    • Plymouth, Michigan, United States, 48170
      • SRI International - ClinEdge
  • North Carolina
    • Raleigh, North Carolina, United States, 27607
      • Velocity Clinical Research
  • Tennessee
    • Chattanooga, Tennessee, United States, 37403
      • Erlanger Neuroscience Institute
    • Nashville, Tennessee, United States, 37232
      • Vanderbilt University Medical Center
  • Texas
    • Austin, Texas, United States, 78759
      • National Neuromuscular Research Institute
    • Cypress, Texas, United States, 77429
      • Northwest Houston Neurology - Cypress
    • Cypress, Texas, United States, 21216
      • Horizon Clinical Research: Gill Neuroscience
    • Dallas, Texas, United States, 75251
      • Cedar Health Research - Dallas

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Is at least 18 years of age and the local legal age of consent
• Is diagnosed with CIDP (confirmed or possible CIDP) according to the criteria of the European Academy of Neurology/Peripheral Nerve Society
• Is being treated with IVIg every 3-6 weeks, on a stable dose and dosing interval (between 0.5-2 g/kg) for at least 3 doses
• If receiving oral corticosteroids, this should be at a stable dose of less than 20 mg a day or less than 40 mg every other day, for at least a month.
• If receiving nonsteroidal immunosuppressive medication, this should be at a stable dose for at least 3 months

Exclusion Criteria:

• Besides the indication under study, known autoimmune disease or any medical condition that would interfere with an accurate assessment of clinical symptoms of CIDP or puts the participant at undue risk
• Types of other polyneuropathy other than CIDP

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Efgartigimod PH20 SC; Participants start efgartigimod PH20 SC treatment after discontinuing IVIg	Biological: Efgartigimod PH20 SC; Subcutaneous injection of efgartigimod PH20 SC

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Proportion of participants who begin treatment with efgartigimod PH20 SC within 1 week after stopping IVIg therapy and are still receiving efgartigimod PH20 SC at the end of the 12-week treatment period	Up to 12 weeks

Secondary Outcome Measures

Outcome Measure	Time Frame
Changes from baseline in EQ-5D-5L scores over time	Up to 12 weeks
Changes from baseline in TSQM-9 scores over time	Up to 12 weeks
Changes from baseline in PGI-C scores over time	Up to 12 weeks
Changes from baseline in PGI-S scores over time	Up to 12 weeks
Incidence of (S)AEs	Up to 16 weeks

Collaborators and Investigators

• Sponsor: argenx

Study record dates

Study Major Dates

• Study Start (Actual): December 10, 2024
• Primary Completion (Actual): February 19, 2026
• Study Completion (Actual): February 19, 2026

Study Registration Dates

• First Submitted: October 7, 2024
• First Submitted That Met QC Criteria: October 9, 2024
• First Posted (Actual): October 15, 2024

Study Record Updates

• Last Update Posted (Actual): April 6, 2026
• Last Update Submitted That Met QC Criteria: April 3, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Nervous System Diseases; Pathologic Processes; Neuromuscular Diseases; Chronic Disease; Disease Attributes; Autoimmune Diseases; Immune System Diseases; Peripheral Nervous System Diseases; Autoimmune Diseases of the Nervous System; Demyelinating Diseases; Polyneuropathies; Polyradiculoneuropathy; Pathological Conditions, Signs and Symptoms; Polyradiculoneuropathy, Chronic Inflammatory Demyelinating
• Other Study ID Numbers: ARGX-113-2406

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No