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Active, Not Recruiting

NCT Number: NCT04280718

A Study to Assess the Long-term Safety and Efficacy of a Subcutaneous Formulation of Efgartigimod in Adults With Chronic Inflammatory Demyelinating Polyneuropathy (CIDP, an Autoimmune Disorder That Affects the Peripheral Nerves)

This is the open-label extension study of phase II ARGX-113-1802 to evaluate the long-term safety and efficacy of the subcutaneous formulation of efgartigimod in adults with CIDP.

Patients already stabilized on efgartigimod PH20 SC will also have the opportunity to participate in a sub study to explore less frequent dosing of efgartigimod PH20 SC.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Key information

Conditions

Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) Autoimmune Diseases Autoimmune Diseases of the Nervous System Chronic Disease Demyelinating Diseases Disease Attributes Immune System Diseases Nervous System Diseases Neuromuscular Diseases Pathologic Processes Pathological Conditions, Signs and Symptoms Peripheral Nervous System Diseases Polyneuropathies Polyradiculoneuropathy Polyradiculoneuropathy, Chronic Inflammatory Demyelinating

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2

Primary location

Investigator site 0430007, Innsbruck, Austria

Loading trial locations.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Ability to understand the requirements of the trial, provide written informed consent (including consent for the use and disclosure of research-related health information), willingness and ability to comply with the trial protocol procedures (including required trial visits) of this trial.
  • Male or female patient with one of the following options:
  • Have completed the Week-48 visit of Stage B of the ARGX-113-1802 trial and are considered to be eligible for treatment with efgartigimod PH20 SC; or
  • Have deteriorated during Stage B of the ARGX-113-1802 trial and are considered to be eligible for treatment with efgartigimod PH20 SC, or
  • Have been offered the participation in the OLE trial due to early termination of the ARGX-113-1802 trial (because sufficient events for the primary endpoint analysis of the that trial have been reached and it is stopped) and are considered to be eligible for treatment with efgartigimod PH20 SC treatment; or
  • Have completed the Week-48 visit of the previous cycle of the OLE trial and are considered to be eligible to continue with efgartigimod PH20 SC treatment.
  • Women of childbearing potential who have a negative urine pregnancy test at baseline before IMP administration.
  • Women of childbearing potential must use an acceptable method of contraception from signing the ICF until the date of the last administration of IMP.

Exclusion criteria

  • Week-48/ED visit in the ARGX-113-1802 trial or the Week-48 visit of the previous OLE participation occurred more than 14 days prior to SD1 of the OLE trial or the start of a new treatment cycle in the OLE trial and more than 21 days since the last dose of IMP.
  • Pregnant and lactating women and those intending to become pregnant during the trial.
  • Patients with clinical evidence of other significant serious disease or patients who underwent a recent or have a planned major surgery, or patients who (intend to) use prohibited medications (see protocol) and therapies during the trial, or any other reason which could confound the results of the trial or put the patient at undue risk.

Treatment and study plan

efgartigimod PH20 SC

Biological

Subcutaneous administration of efgartigimod

Other names: ARGX-113

Primary outcomes

  1. Incidence of treatment-emergent adverse events and serious adverse events

    Time frame: Up to 48 weeks per cycle (each cycle is 48 weeks) until the end of the study

Secondary outcomes

  1. Change from baseline over time of the adjusted INCAT score

    Time frame: Up to 48 weeks per cycle (each cycle is 48 weeks) until the end of the study

    The Adjusted Inflammatory Neuropathy Cause and Treatment Disability Score (aINCAT) score is a 10-point scale that covers the functionality of legs and arms. The score varies between 0 and 10 (higher score, worse outcome).

  2. Change from baseline over time of the MRC Sum score

    Time frame: Up to 48 weeks per cycle (each cycle is 48 weeks) until the end of the study

    The Medical Research Council Sum Score evaluates motor strength. Evaluated on 6 muscle groups on each side, the score varies from 0 to 60 (lower score, worse outcome).

  3. Change from baseline over time of I-RODS disability scores

    Time frame: Up to 48 weeks per cycle (each cycle is 48 weeks) until the end of the study

    Inflammatory Rasch-built Overall Disability Scale (I-RODS) assesses the limitations of activities and social participation in patients with inflammatory neuropathies like CIDP. The score ranges from 0 to 100 (higher score, worse outcome).

  4. Change from baseline over time of mean grip strength

    Time frame: Up to 48 weeks per cycle (each cycle is 48 weeks) until the end of the study

  5. Change from baseline over time of TUG score

    Time frame: Up to 48 weeks per cycle (each cycle is 48 weeks) until the end of the study

    The Timed Up and Go Test (TUG) is a simple test to assess a person's mobility in which the time expended to rise from a chair, walk 3 meters, turn around, walk back to the chair, and sit down is measured.

  6. Percentage of patients without clinical deterioration over time, defined by adjusted INCAT deterioration ≥1 point compared to baseline.

    Time frame: Up to 48 weeks per cycle (each cycle is 48 weeks) until the end of the study

    The Adjusted Inflammatory Neuropathy Cause and Treatment Disability Score (aINCAT) score is a 10-point scale that covers the functionality of legs and arms. The score varies between 0 and 10 (higher score, worse outcome).

  7. Percentage of patients with titers of binding antibodies towards efgartigimod and the presence of neutralizing antibodies against efgartigimod.

    Time frame: Up to 51 weeks

  8. Efgartigimod serum concentrations

    Time frame: Up to 51 weeks

  9. Changes from baseline over time of serum IgG levels (total)

    Time frame: Up to 48 weeks per cycle (each cycle is 48 weeks) until the end of the study

  10. Change from baseline over time in EQ-5D-5L

    Time frame: Up to 48 weeks per cycle (each cycle is 48 weeks) until the end of the study

    EQ-5D-5L questionnaire is a patient-reported outcome measure, ranging 0 to 100 (lower score, worse outcome).

  11. Change from baseline over time in BPI SF

    Time frame: Up to 48 weeks per cycle (each cycle is 48 weeks) until the end of the study

    The Brief Pain Inventory-Short Form (BPI-SF) is a patient-reported outcome measure to assess pain severity and pain interference

  12. Change from baseline over time in TSQM-9

    Time frame: Up to 48 weeks per cycle (each cycle is 48 weeks) until the end of the study

    The Treatment Satisfaction Questionnaire for Medication (TSQM) is a 9-item questionnaire to assess treatment satisfaction in naturalistic study designs, in which there is potential that the administration of the side effects domain of the TSQM would interfere with routine clinical care

  13. Change from baseline over time in RT-FSS

    Time frame: Up to 48 weeks per cycle (each cycle is 48 weeks) until the end of the study

    The Rasch-Transformed Fatigue Severity Scale (RT-FSS) is a 7-item self-reported questionnaire designed to differentiate fatigue from clinical depression. The participant has to rate from 0 to 3 their level of fatigue on 7 items (low score indicates that the statement is not very appropriate, and high score indicates agreement).

  14. Change from baseline over time in HADS

    Time frame: Up to 48 weeks per cycle (each cycle is 48 weeks) until the end of the study

    The Hospital Anxiety and Depression Scale (HADS) aims to measure symptoms of anxiety and depression in people with physical health problems. HADS is a 14-item scale with 7 items related to anxiety and 7 to depression

  15. Percentage of patients performing self-administration over time

    Time frame: Up to 48 weeks per cycle (each cycle is 48 weeks) until the end of the study

  16. Percentage of patients with treatment administered by caregiver over time.

    Time frame: Up to 48 weeks per cycle (each cycle is 48 weeks) until the end of the study

Sponsors and collaborators

Lead sponsor

argenx

Industry

Registry information

Official study title

Open-label Extension of the ARGX-113-1802 Trial to Investigate the Long-term Safety, Tolerability, and Efficacy of Efgartigimod PH20 SC in Patients With Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)

Acronym: ADHERE+

Important dates

Study start
2020
Primary completion
2027
Study completion
2027
First posted
Feb 21, 2020
Registry last updated
Jun 29, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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