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Study on Long-term Safety and Efficacy of Efgartigimod PH20 SC in Adults with Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)

Verified siteInvestigationalNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying the long-term safety and effectiveness of a treatment for Chronic Inflammatory Demyelinating Polyneuropathy (CIDP), which is an autoimmune disorder affecting the peripheral nerves. The treatment being investigated is called efgartigimod, specifically in a form that is injected under the skin. This study aims to understand how well patients tolerate this treatment over an extended period.

Participants in the study will receive efgartigimod injections and will be monitored for any side effects or changes in their condition. The study will also include a comparison with a placebo to evaluate the treatment's effectiveness. Throughout the study, various health assessments will be conducted to track the participants' progress and any potential improvements in their symptoms.

The study is designed to gather information on how efgartigimod affects patients with CIDP over time, including any changes in their ability to perform daily activities and their overall quality of life. The goal is to determine if this treatment can provide a safe and effective option for managing this condition in the long term.

The research process

The trial runs in 7 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the trial

    Upon joining the trial, you will be required to provide written consent, confirming your understanding of the trial requirements and your willingness to comply with the procedures.

    You will need to confirm your eligibility, which includes having completed certain stages of a previous trial or being offered participation due to specific circumstances.

  2. Step 2

    Initial assessment

    An initial assessment will be conducted to ensure you meet all necessary criteria, including a negative pregnancy test for women of childbearing potential.

    You will be informed about the importance of using an acceptable method of contraception during the trial.

  3. Step 3

    Medication administration

    You will receive the medication efgartigimod PH20 SC, which is a solution for injection administered subcutaneously (under the skin).

    The frequency and dosage will be determined by the trial protocol, and you will be informed about the schedule for your injections.

  4. Step 4

    Regular study visits

    You will attend regular study visits where various assessments will be conducted, including blood sampling to monitor for any significant laboratory abnormalities.

    During these visits, your health and response to the medication will be closely monitored.

  5. Step 5

    Monitoring and assessments

    Throughout the trial, the incidence of any adverse events will be recorded, and your overall health will be assessed.

    You will be asked to complete questionnaires about your quality of life, pain levels, treatment satisfaction, and any feelings of anxiety or depression.

  6. Step 6

    Self-administration training

    You may be trained to self-administer the medication, or a caregiver may be instructed on how to assist you with the injections.

    The percentage of patients performing self-administration will be monitored over time.

  7. Step 7

    Completion of trial

    Upon completion of the trial, a final assessment will be conducted to evaluate your overall health and the effects of the medication.

    You will be informed about any follow-up procedures or additional steps required after the trial ends.

Who can join the trial?

9 criteria

  • The patient must be able to understand the trial requirements and agree to participate by signing a consent form. This includes agreeing to share health information related to the research.
  • The patient must be willing and able to follow the trial procedures, including attending required trial visits.
  • The patient must be either male or female.
  • The patient must have one of the following conditions:
    • Completed the Week-48 visit of Stage B of a previous trial and be eligible for treatment in this study.
    • Experienced worsening of their condition during Stage B of a previous trial and be eligible for treatment in this study.
    • Been offered participation in this study due to early termination of a previous trial and be eligible for treatment.
    • Completed the Week-48 visit of a previous cycle of this study and be eligible to continue treatment.
    • Women of childbearing potential (women who can become pregnant) must have a negative pregnancy test before starting the trial medication.
    • Women of childbearing potential must use an acceptable method of birth control from the time they sign the consent form until the last dose of the trial medication.

Who cannot join the trial?

10 criteria

  • Patients with any other **serious health conditions** that might interfere with the study.
  • Patients who are **pregnant** or **breastfeeding**.
  • Patients who have a history of **allergic reactions** to the study medication or similar drugs.
  • Patients who are currently participating in another clinical trial.
  • Patients who have had a **major surgery** within the last 3 months.
  • Patients with **uncontrolled high blood pressure** or other significant heart problems.
  • Patients with **active infections** that require treatment.
  • Patients with a history of **substance abuse** or **alcohol dependency**.
  • Patients who have received any **live vaccines** within the last 4 weeks.
  • Patients with **autoimmune diseases** that are not stable or controlled.
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Investigated drugs

Efgartigimod PH20 SC is a medication being studied for its long-term safety and effectiveness in treating a condition called Chronic Inflammatory Demyelinating Polyneuropathy (CIDP). This condition affects the nerves and can cause weakness and numbness. Efgartigimod PH20 SC is designed to be given as an injection under the skin. It combines two components: efgartigimod, which helps to reduce the harmful antibodies that attack the nerves, and recombinant human hyaluronidase PH20, which helps the medication spread more easily under the skin. This combination aims to provide relief from the symptoms of CIDP by targeting the underlying cause of the nerve damage.

What is already known about the treatment

Efgartigimod PH20 SC – This medication is administered as a subcutaneous injection, meaning it is given under the skin. It is currently being studied in clinical trials to evaluate its long-term safety and effectiveness for treating Chronic Inflammatory Demyelinating Polyneuropathy (CIDP), a condition that affects the nerves. Efgartigimod works by targeting and reducing specific proteins in the immune system that are involved in inflammation and nerve damage. It belongs to a class of drugs known as immunomodulators, which help regulate the immune system's activity.

Investigated diseases

Chronic Inflammatory Demyelinating Polyneuropathy – Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) is a neurological disorder characterized by progressive weakness and impaired sensory function in the legs and arms. It is caused by damage to the myelin sheath, the protective covering of the nerves. The disease progresses slowly, with symptoms that may include tingling or numbness, muscle weakness, and loss of deep tendon reflexes. Over time, these symptoms can lead to difficulty walking and performing daily activities. CIDP can vary greatly in its progression, with some individuals experiencing periods of improvement and others having a steady decline in function.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IITrial ID2023-507885-21-00Protocol codeARGX-113-1902Estimated enrolment236 patientsSponsorArgenx

sourced from the EU Clinical Trials Register and site verification

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