An Open-label Study of CND261 in Seropositive Rheumatoid Arthritis

Inclusion Criteria: 1. 18 to 75 years old 2. Diagnosis of adult-onset RA 3. Class I-III RA 4. Moderately to severely active RA 5. Inadequate treatment response as defined in the protocol 6. Stable use of any concomitant therapies Exclusion Criteria: 1. Inadequate clinical laboratory parameters at Screening 2. Active infection 3. Receipt of or inability to discontinue any excluded therapies 4. Receipt of live vaccine within 4 weeks 5. Presence of any concomitant autoimmune disease 6. Active or known history of catastrophic anti-phospholipid syndrome 7. APS or thrombotic event not adequately controlled by anticoagulation therapy 8. History of progressive multifocal leukoencephalopathy 9. Central nervous system disease 10. Presence of 1 or more significant concurrent medical conditions 11. Have a diagnosis or history of malignant disease within 5 years 12. Serious mental illness, alcohol or drug abuse, dementia, or any other condition that would impair ability to receive planned treatment or to understand informed consent 13. History of or planned organ transplant and/or autologous or allogeneic hematopoietic stem cell transplantation 14. Major surgery requiring use of general anesthesia within 12 weeks or planned or expected major surgery during the study 15. Women who are pregnant or breastfeeding 16. Patients who do not agree to the use of highly effective contraception as defined by the protocol