A PHASE 3 RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED STUDY TO EVALUATE THE EFFICACY AND SAFETY OF DNTH103 IN ADULTS WITH CHRONIC INFLAMMATORY DEMYELINATING POLYNEUROPATHY (CAPTIVATE)

Study on Investigational Medication for CIDP

C
Cynthia Bodkin, MD

Primary Investigator

Enrolling By Invitation
18 years - 75 years
All
Phase 3
2 participants needed
1 Location

Brief description of study

The purpose of this Phase 3 study is to demonstrate the efficacy of DNTH103 as compared to placebo in participants with chronic inflammatory demyelinating polyneuropathy (CIDP).

THIS STUDY IS ENROLLING BY INVITATION ONLY   

Detailed description of study

The study consists of the following periods:
Screening Period: Up to 6 weeks. Following discussion and agreement between the Investigator and the Medical
Monitor, the Screening period may be extended as follows (if applicable):
• An additional 7 days may be requested to ensure the last dose of immunoglobulins (Ig) is at least
1 week prior to Part A Day 1.
• An additional 3 weeks may be requested to complete and stabilize oral corticosteroid tapering (total
maximum 9 weeks Screening period).

Part A: An open-label period of up to 13 weeks (note: an additional 2 weeks for confirmation of a response that
occurs at Week 13 is allowed).
Part B: A randomized, placebo-controlled, double-blind treatment period of up to 52 weeks for participants who
respond to DNTH103 in Part A (note: an additional 7 days for confirmation of a relapse if it occurs at Week 52 is
allowed).
Optional open label extension (OLE): up to 104 weeks for participants who complete the 52-week treatment
period or who relapse in Part B.
Safety Follow-up: 40 weeks for all participants.

Eligibility of study

You may be eligible for this study if you meet the following criteria:

  • Conditions: Chronic inflammatory demyelinating polyneuropathy, CIDP
  • Age: 18 years - 75 years
  • Gender: All

Inclusion Criteria:

  1. Must have given written informed consent before any study-related activities are carried out.
  2. Weight range between 40 kilograms (kg) and 120 kg.
  3. Confirmed diagnosis of CIDP or possible CIDP. Participants must have either typical CIDP or one of the following variants: motor or multifocal CIDP. Diagnosis must be confirmed by the Independent CIDP Review Panel.
  4. CIDP Disease Activity Status (CDAS) score ≥ 3 at screening.
  5. Must be neurologically stable.
  6. Must have an INCAT score between 2 and 9 inclusive.
  7. Must fulfill one of the following treatment conditions for CIDP:
    1. Currently treated with and responded to immunoglobulin (Ig) (intravenous immunoglobulin [IVIg] or subcutaneous immunoglobulin [SCIg]) alone or Ig (IVIg or SCIg) plus oral corticosteroids, or previously treated with and responded to, but are no longer being treated with (eg, lost access to), a maintenance regimen of Ig (IVIg or SCIg) alone or Ig (IVIg or SCIg) plus oral corticosteroids.
    2. Currently treated with and responded to oral corticosteroids alone or oral corticosteroids in combination with azathioprine or mycophenolate mofetil.
    3. Refractory participants who have had treatment failure (worsening) or an inadequate response to Ig and/or oral corticosteroids (defined as no clinically meaningful improvement after a period of a minimum of 12 weeks, which may include both active treatment and observation to assess response), or who at any time were unable to tolerate these treatments, experienced adverse effects, or have documented contraindications.
    4. Treatment naïve with no history of prior treatment for CIDP.
  8. Documented vaccinations against encapsulated bacteria in accordance with local requirements and vaccine availability.
  9. Female participants must be of nonchildbearing potential or if of childbearing potential, must agree not to donate ova, not to attempt to become pregnant and, if engaging in sexual intercourse with a male partner, must agree to use a highly effective method of contraception.
  10. Male participants must be surgically sterile for at least 90 days prior to Screening or agree not to donate sperm and, if engaging in sexual intercourse with a female partner who could become pregnant, must agree to use an acceptable method of contraception.

Exclusion Criteria:

  1. Clinical signs or symptoms suggestive of polyneuropathy of causes other than CIDP.
  2. Known evidence of central demyelination or known history of myelopathy.
  3. History or presence of significant medical/surgical condition including any acute illness or major surgery considered to be clinically significant or that could have a potential impact on safety/efficacy or study procedures.
  4. Any other condition, including mental illness or prior therapy that would make the participant unsuitable for this study.
  5. Known complement deficiency or history of positive titer for anti-C1 antibodies.
  6. Diagnosis of systemic lupus erythematosus (SLE) or family history of SLE (defined as a parent, sibling, or child).
  7. Participants with an autoimmune disease affecting joints, muscle or nervous system.
  8. Any coexisting or overlapping condition, which may interfere with outcome assessments, such as severe diabetic neuropathy, fibromyalgia, inflammatory arthritis or osteoarthritis affecting the hands and feet.
  9. Prior history of N. meningitidis infection.
  10. History of active malignancy within 5 years prior to screening, except basal cell carcinoma of the skin, curatively resected squamous cell carcinoma of the skin, cervical carcinoma in situ curatively treated or low-grade prostate adenocarcinoma for which appropriate management is observation alone.
  11. Positive test results for active human immunodeficiency virus (HIV-1 or HIV-2), hepatitis B surface antigen (HBsAg), or hepatitis C virus (HCV) antibodies.

This study investigates the effects of an investigational medication compared to a placebo in adults with Chronic Inflammatory Demyelinating Polyneuropathy (CIDP). CIDP is a condition where the body's immune system attacks the protective covering of the nerves, leading to weakness and numbness. The study aims to understand how well the investigational medication works and how safe it is for people with CIDP.

Participants in the study will first go through a screening period, followed by an open-label treatment phase to see if they respond to the investigational medication. Those who respond will then enter a double-blind phase where they receive either the investigational medication or a placebo. A placebo is an inactive substance that looks like the investigational medicine but does not contain any medicine. The study also includes a safety follow-up and optional extension period for further observation.

  • Who can participate: Adults with CIDP or possible CIDP, weighing between 40 kg and 120 kg, and who are neurologically stable, may participate. Participants must meet specific CIDP treatment conditions.
  • Study details: Participants will receive either the investigational medication or a placebo. The study includes screening, treatment phases, and follow-up to monitor safety and effectiveness.
Updated on 06 Mar 2026. Study ID: NEUR-DIANTHUS-CAPTIVATE, 25377
Please visit our main page to search for other studies you may be interested in. If you need help finding a study or have any questions, please contact us at inhealth@iu.edu

Interested in the study?

This study is accepting only persons who receive care at a certain clinic or doctor or who are part of an invited group. Questions about this study can be directed to the study team listed in the description or contact your doctor to see if you are eligible.

Accepting Referrals by Invitation Only