A Study of the Efficacy and Safety of Efgartigimod in Patients With Primary Sjögren's Syndrome

Inclusion Criteria:

• Is at least 18 years of age and the local legal age of consent for clinical studieswhen signing the ICF.

• Meets the following criteria at screening: fulfilled ACR/EULAR classificationcriteria 2016 PSjD criteria before screening; clinESSDAI ≥ 6 at screening;Anti-Ro/SS-A positive at central laboratory; Unstimulated residual salivary flow (≥ 0.01 mL/min)

Exclusion Criteria:

• Secondary (also referred to as associated) Sjögren's disease, defined as overlapwith another autoimmune rheumatic or systemic inflammatory condition (eg, rheumatoidarthritis, systemic lupus erythematosus, scleroderma, or idiopathic inflammatorymyopathy

• Active fibromyalgia which is not adequately controlled in the judgment of theinvestigator, or participant is receiving fibromyalgia treatment that has not beenstable treatment for at least 12 weeks before screening.

• Any severe systemic pSjD manifestation that is not adequately controlled atscreening or baseline that may put the participant at undue risk based on theinvestigator's opinion.

• Use of cyclophosphamide ≤ 24 weeks prior to screening

• Anti-CD20 or anti-CD19 antibody received < 6 months before screening