A Study to Evaluate the Efficacy and Safety of DNTH103 in Adults With Chronic Inflammatory Demyelinating Polyneuropathy (CAPTIVATE)

Inclusion Criteria:

1. Must have given written informed consent before any study-related activities arecarried out.

2. Weight range between 40 kilograms (kg) and 120 kg.

3. Confirmed diagnosis of CIDP or possible CIDP. Participants must have either typicalCIDP or one of the following variants: motor or multifocal CIDP. Diagnosis must beconfirmed 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:

8. Currently treated with and responded to immunoglobulin (Ig) (intravenousimmunoglobulin [IVIg] or subcutaneous immunoglobulin [SCIg]) alone or Ig (IVIgor SCIg) plus oral corticosteroids, or previously treated with and respondedto, but are no longer being treated with (eg, lost access to), a maintenanceregimen of Ig (IVIg or SCIg) alone or Ig (IVIg or SCIg) plus oralcorticosteroids.

9. Currently treated with and responded to oral corticosteroids alone or oralcorticosteroids in combination with azathioprine or mycophenolate mofetil.

10. Refractory participants who have had treatment failure (worsening) or aninadequate response to Ig and/or oral corticosteroids (defined as no clinicallymeaningful improvement after a period of a minimum of 12 weeks, which mayinclude both active treatment and observation to assess response), or who atany time were unable to tolerate these treatments, experienced adverse effects,or have documented contraindications.

11. Treatment naïve with no history of prior treatment for CIDP.

12. Documented vaccinations against encapsulated bacteria in accordance with localrequirements and vaccine availability.

13. Female participants must be of nonchildbearing potential or if of childbearingpotential, must agree not to donate ova, not to attempt to become pregnant and, ifengaging in sexual intercourse with a male partner, must agree to use a highlyeffective method of contraception.

14. Male participants must agree not to donate sperm and, if engaging in sexualintercourse with a female partner who could become pregnant, must agree to use anacceptable method of contraception or be surgically sterile for at least 90 daysprior to Screening.

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 acuteillness or major surgery considered to be clinically significant or that could havea potential impact on safety/efficacy or study procedures.

4. Any other condition, including mental illness or prior therapy that would make theparticipant 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 asa 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 outcomeassessments, such as severe diabetic neuropathy, fibromyalgia, inflammatoryarthritis 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 cellcarcinoma of the skin, curatively resected squamous cell carcinoma of the skin,cervical carcinoma in situ curatively treated or low-grade prostate adenocarcinomafor 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.