An Open-label Study of Cizutamig in Refractory Seropositive Rheumatoid Arthritis

Inclusion Criteria: 1. 18 to 75 years old at the time of signing the informed consent form 2. Diagnosis of adult-onset RA as defined by the 2010 ACR/EULAR classification criteria 3. Moderately to severely active RA. 4. Positive test results for RF and/or ACPA at Screening. Inadequate treatment response defined as either lack of clinical benefit or intolerability to treatment with tsDMARD and/or bDMARD Exclusion Criteria: 1. Inadequate clinical laboratory parameters at Screening 2. Patients with active infection 3. Receipt of live vaccine within 4 weeks prior to Screening 4. Presence of any concomitant autoimmune disease 5. History of progressive multifocal leukoencephalopathy 6. History of primary immunodeficiency or a hereditary deficiency of the complement system 7. Central nervous system disease 8. Presence of 1 or more significant concurrent medical conditions per investigator judgment 9. Have a diagnosis or history of malignant disease within 5 years 10. Serious mental illness, alcohol or drug abuse, dementia, or any other condition that would impair the patient's ability to receive the planned treatment or to understand informed consent at the study site as determined by local practice