Inclusion Criteria:
* Males and females at least 18 years of age at the time of signing the ICF.
* Diagnosed with CIDP or Possible CIDP according to criteria of the EAN/PNS 2021 (Van den Bergh, 2021). (Diagnosis is to be confirmed by an independent adjudication committee; refer to Section 8.1.1).
* Must have an adjusted INCAT score as follows:
1. Treatment-naïve participants: ≥2 at screening
2. Treatment-experienced participants: 2-7 at screening Note: A score of 2 should be exclusively from leg disability component of adjusted INCAT. For participants with an adjusted INCAT score of ≥3 (and up to 7 for treatment-experienced; no upper limit for treatment-naïve) at study entry, there are no specific requirements for arm or leg scores.
* Treatment-experienced participants: Participants who were treated with IVIg/SCIg at the time of screening must have documented evidence within 24 months of screening of:
1. Clinically meaningful deterioration on treatment interruption or dose reduction of standard of care (SOC) therapy, determined by clinical examination documented in the medical records. Clinically meaningful deterioration is defined as one of the following: ≥1-point increase in adjusted INCAT score, decrease in I-RODS total score ≥4 points, decrease in MRC Sum score ≥3, grip strength worsening of ≥8 kPa (in either hand), or an equivalent deterioration based on information from medical records and at the investigator's judgement.
OR
2. Improvement in CIDP symptoms with SOC therapy based on information in medical records and at the investigator's judgement. In assessing the history of response to IVIg/SCIg, the investigator should account for prior treatment (type, dose regimen, duration), pattern of response or non-response to treatment.
* a. Treatment-naïve participants: No prior treatment with IVIg and/or SCIg and/or corticosteroids and/or investigational therapies for CIDP.
OR b. Treatment-experienced participants: On stable dose of IVIg or SCIg with no disease exacerbations for 8 weeks prior to screening. Participants must be willing to discontinue IVIg or SCIg at least 3 weeks (±1 week) prior to dosing with the study drug. Participants on IVIg must be on maintenance dose of 0.4 to 1 g/kg every 2 to 6 weeks per EAN/PNS recommendation. Participants on SCIg should not exceed the dose of 0.4 g/kg per week.
Exclusion Criteria:
* Pure sensory or distal CIDP variants (EAN/PNS definition)
* History of being non-responder or loss of response to IVIg or SCIg per Investigator's determination. In assessing the history of response or loss of response to IVIg/SCIg, the investigator should account for prior treatment (type, dose regimen, duration), pattern of response or non-response to treatment. Note, participants who are on IVIg but relapsed on SCIg will be allowed to enter the study.
* Polyneuropathy of other causes, including the following: multifocal motor neuropathy; polyneuropathy associated with anti-myelin associated glycoprotein (MAG) antibodies, polyneuropathy associated with IgM monoclonal gammopathy; hereditary demyelinating neuropathy; polyneuropathy, organomegaly, endocrinopathy, monoclonal protein and skin change syndromes (POEMS); lumbosacral radiculoplexus neuropathy; polyneuropathy most likely due to diabetes mellitus; polyneuropathy most likely due to systemic illnesses; drug- or toxin-induced polyneuropathy.
* Acute demyelinating neuropathies including Guillain-Barre syndrome.
* Any other disease that could better explain the participant's signs and symptoms.
* Any history of myelopathy or evidence of central demyelination.
* Any other known autoimmune disease that, in the opinion of the investigator, would interfere with an accurate assessment of clinical symptoms of CIDP.
* Severe psychiatric disorder (such as severe depression, psychosis, bipolar disorder), history of suicide attempt, or current suicidal ideation that in the opinion of the investigator could create undue risk to the patient or could affect adherence with the study protocol.
