An Open-label Phase 2a Study to Evaluate the Safety and Efficacy of AlloNK®, an Allogeneic Cord Blood-derived NK Cell Therapy, in Combination With Rituximab in Relapsing Forms of B-cell Dependent Rheumatologic Diseases

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 asse…