A Study to Evaluate the Efficacy, Safety, and Tolerability of IMVT-1402 in Adult Participants With Active, Difficult to Treat Rheumatoid Arthritis

Inclusion Criteria:

• Diagnosis of 'definite RA' according to the 2010 ACR/ European Alliance ofAssociations for Rheumatology (EULAR) Rheumatoid Arthritis Classification Criteria.

• Greater than or equal to 6/68 TJC and ≥ 6/66 SJC at both Screening and Baselinevisits.

• C-reactive protein ≥ 1.5 × upper limit of normal (ULN) at Screening Visit.

• DAS28-CRP > 4.1 at the Screening Visit.

• Elevated immunoglobulin G (IgG) + ACPA at the Screening Visit.

• Inadequate response to at least 2 classes of biologic/targeted synthetic DMARDs.

Additional inclusion criteria are defined in the protocol.

Exclusion Criteria:

• Have received rituximab and experienced insufficient efficacy or loss of efficacy

• History of any chronic inflammatory arthritis with onset prior to age 18 or historyof acute inflammatory joint disease of different origin from RA.

• Active malignancy or history of malignancy within 5 years prior to Screening Visit.

• Medical history of primary immunodeficiency, T cell or humoral, including commonvariable immunodeficiency.

• Used any non-immunosuppressive Fc-based therapeutic protein (e.g., mAb or Fc-fusionprotein) within 4 weeks prior to or at Screening Visit.

• Used any anti-FcRn treatment within 2 months prior to or at Screening Visit or havea documented history of non-response to prior anti-FcRn treatment.

Other, more specific exclusion criteria are defined in the protocol.