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 (ie, no relapses or other neurological events thatcould affect examinations).

6. Must have an adjusted 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 either no longer have access to or are no longer being treated with, Ig (IVIg or SCIg) alone or Ig (IVIg or SCIg) plus oral corticosteroids.

9. Currently treated with and responded to oral corticosteroids alone or oralcorticosteroids in combination with azathioprine or mycophenolate mofetil, orpreviously treated with and responded to, but no longer have access to, oralcorticosteroids.

10. Refractory participants who have had failure (worsened) or an inadequateresponse (defined as no clinically meaningful improvement after treatment for aminimum of 12 weeks on Ig and/or oral corticosteroids) or are unable totolerate these treatments due to side effects.

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 be surgically sterile for at least 90 days prior to Screeningor agree not to donate sperm and, if engaging in sexual intercourse with a femalepartner who could become pregnant, must agree to use an acceptable method ofcontraception.

Exclusion Criteria:

1. Clinical signs or symptoms suggestive of polyneuropathy of other causes, such asinflammatory neuropathies.

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. Diagnosis of an autoimmune disorder other than CIDP.

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.