The goal of this clinical trial is to evaluate the efficacy and safety of intravenous infusions of burfiralimab (hzVSF-v13) when added to Disease-Modifying Antirheumatic Drug (DMARD) treatment as Standard of Care (SOC) in participants with moderate to severe Rheumatoid Arthritis (RA).

This study is a Phase 2a, multi-center, randomized, double-blind, placebo-controlled. Efficacy and safety of biweekly intravenous infusions of burfiralimab (hzVSF-v13), added to DMARD treatment as standard of care, is evaluated in comparison with placebo. Participants of either sex, aged, 18~80years, are enrolled it they have moderate to severe RA and had an inadequate response to disease-modifying antirheumatic drug(DMARD) treatments. The study consists of a screening period for up to 4 weeks, a treatment period of 10 weeks. Eligible participants are randomized in a 1:1:1 ratio to 1 of the 3 treatment groups: 200mg burfiralimab (hzVSF-v13) + SOC (study group 1), 600mg burfiralimab (hzVSF-v13) + SOC (study group 2), or placebo + SOC (control group). The primary focus of the study is to evaluate preliminary of the 2 doses of burfiralimab (hzVSF-v13, 200mg to 600mg) administered by IV infusion biweekly for 10 weeks when compared to placebo in lowering disease activity in participants. Efficacy analyses evaluate disease and health-related quality of life improvements at week 12 and week 18. Safety is assessed at up to 18 weeks.

Inclusion Criteria:

1. Participant has a diagnosis of adult-onset RA for at least 3 months prior to Screening, as defined by the 2010 ACR/European League Against Rheumatism (EULAR) classification criteria.
2. Participant has moderate to severe RA at Screening and Baseline.
3. Participant has had an inadequate response to, loss of response, or intolerance to at least 2 bDMARDs or tsDMARDs.
4. Participant is positive for anti-citrullinated protein antibodies (ACPA).
5. Participant has a C-reactive protein (CRP) > upper limit normal (ULN) (5.0 g/L).
6. Participant has a negative tuberculosis test at Screening, defined as either negative QuantiFERON® test or purified protein derivative <5 mm of induration at 48 to 72 hours after the test was placed.

Exclusion Criteria:

1. Participant has Class IV RA according to ACR revised response criteria.

2. Participant has 1 or more significant concurrent medical conditions per investigator judgment, including but not limited to the following:

   • Poorly controlled diabetes or hypertension,
   • Chronic kidney disease stage IIIb, IV, or V,
   • Symptomatic heart failure according to New York Heart Association Classes II, III, or IV,
   • Myocardial infarction, unstable angina pectoris, stroke, or transient ischemic attack, within the past 12 months before randomization,
   • Severe chronic pulmonary disease, for example, requiring oxygen therapy,
   • Clinically significant hepatic diseases (i.e., hemochromatosis, Wilson's disease, alcoholic hepatitis, autoimmune liver disease, nonalcoholic steatohepatitis, or α-1-antitrypsin deficiency,

3. Participant has known history of prosthetic or native joint infection or human immunodeficiency virus or neurologic symptoms suggestive of central nervous system demyelinating disease.

4. Participant has a chronic inflammatory disease or connective tissue disease other than RA, including but not limited to; systemic lupus erythematosus, psoriatic arthritis, axial spondyloarthritis including ankylosing spondylitis and non radiographic axial spondylarthritis, reactive arthritis, gout, scleroderma, polymyositis, dermatomyositis and/or active fibromyalgia and/or multiple sclerosis.