The goal of this clinical trial is to learn if CIT-013 works to treat rheumatoid arthritis in adults. It will also learn about the safety of CIT-013. The main questions it aims to answer are:

Does CIT-013 lower the disease activity of RA patients? What medical problems do participants have when receiving CIT-013? Researchers will compare CIT-013 to a placebo (a look-alike substance that contains no drug) to see if CIT-013 works to treat the symptoms of RA.

Participants will:

Take receive CIT-013 or placebo every other week for 6 weeks and 50 mg CIT-013 for 6 weeks Visit the clinic once every 2 weeks for checkups and tests Keep monitor their symptoms during this period

Inclusion Criteria:

• Male or female patients with RA according to the 2010 classification criteria of the American College of Rheumatology (ACR) and the European League Against Rheumatism (EULAR) ≥ 3 months prior to screening
• Aged 18-85
• DAS28-CRP ≥ 3.2, with ≥ 3 Swollen Joints, and ≥ 3 Tender Joints, and CRP ≥ ULN at screening and confirmed prior to randomization
• Stable on a conventional synthetic disease modifying antirheumatic drug for ≥ 4 weeks (csDMARD). This drug must have been used for ≥ 3 months.

Exclusion Criteria:

• High clinical activity or disease severity requiring the immediate start of a biological DMARD (bDMARD) or targeted synthetic DMARD (tsDMARD).

• Contra-indication for CIT-013

• Current inflammatory joint disease other than RA (Sjogren with active disease is included).

• The washout period for bDMARD or JAKi prior to the first dose of investigational product should be at least:

  1. ≥ 1 week for etanercept;
  2. ≥ 4 weeks for adalimumab, infliximab, certolizumab, golimumab, abatacept, tocilizumab, and sarilumab;
  3. ≥ 6 months year for rituximab;
  4. ≥ 2 weeks for tsDMARD (either investigational or commercially available treatment).

• Treated with ≥ 3 bDMARD or tsDMARD

• Injectable corticosteroids or treatment with > 10 mg/day dose of oral prednisolone or equivalent within 4 weeks prior to screening.