⁃ For Subjects with Refractory Rheumatoid Arthritis (RA):

• Documented diagnosis of RA, meeting the 2010 ACR/EULAR classification criteria.

• Rheumatoid Factor (RF) or Anti Citrullinated Protein Antibody (ACPA) positive.

• High-sensitivity C-reactive protein (hs-CRP) \> 3 mg/L or Erythrocyte Sedimentation Rate (ESR) \> 28 mm/hr.

• Have had prior treatment for a period of at least 12 weeks with a biologic disease modifying anti-rheumatic drug and were deemed refractory by the treating physician.

• Minimum of six swollen joint counts (SJC) and six tender joint counts (TJC) according to joint assessment.

⁃ For subjects with Sjögren's Disease (SjD)

• Prior diagnosis of Primary SjD as per 2016 ACR/EULAR criteria with confirmatory diagnosis in the 24 weeks preceding screening.

• Total Clinical European League Against Rheumatism Sjogren's Syndrome Disease Activity Index (clinESSDAI) \> 6.

• Salivary Flow Rate \> 0.1 mL/min on stimulation.

⁃ For subjects with Idiopathic Inflammatory Myopathies (IIMs)

• Presence of a positive autoantibody (ANA \>1:80 or RNP or SSA/SSB or other myositis specific autoantibodies.

• Refractory IIM as defined by inadequate response/intolerance to at least 3 months of glucocorticoids and/or at least one other immunosuppressive.

• Muscle biopsy or muscle MRI to confirm IIM diagnosis, where applicable, within 12 months prior to enrollment.

⁃ For Subjects with Systemic Sclerosis (SSc)

• Diagnosis of SSc in accordance with the ACR/EULAR 2013 classification.

• Modified Rodnan skin score (mRSS) \> 10.

• Initial confirmatory diagnosis within 8 years of screening.

• Refractory SSc as defined by inadequate response/intolerance to at least 3 months of glucocorticoids and/or at least one other immunosuppressive.