Study to Investigate the Efficacy, Safety, and Tolerability of FBL-MTX in Patients With Rheumatoid Arthritis

Who May Qualify: - Male or non-pregnant female subjects with moderate-to-severe active RA, age ≥ 18 years, Body Mass Index \> 35 kg/m2. - Diagnosis of RA according to the 2010 classification criteria of the American College of Rheumatology/ European Alliance of Associations for Rheumatology, formerly known as European League Against Rheumatism, (ACR/EULAR), with a Total Score ≥ 6/10. - At least moderately active disease, as defined by DAS28-CRP \>3.2 at Screening and Baseline, including: - Tender joint count (TJC) ≥ 4 - Swollen joint count (SJC) ≥ 4 - C Reactive protein (CRP) ≥ 5 mg/L - Documented history of positive RA factor and/or cyclic citrullinated peptide antibody test. - Chest X-ray performed in the previous 3 months not suggestive of tuberculosis. - If under nonsteroidal anti-inflammatory drugs (NSAIDs), must be able to be on a stable regimen from at least 2 weeks before baseline up to end-of-study. - If under an oral corticosteroid (≤ 10 mg per day of prednisone or equivalent), must be able to be on a stable regimen from at least 4 weeks before baseline up to EoS. - Eligible to start treatment with an immunomodulator. - No evidence of clinically significant active infection. Who Should NOT Join This Trial: - Positive Interferon-Gamma Release Assay (IGRA) test result. - Creatinine clearance \< 60 mL/min. Always talk to your doctor about whether this trial is right for you.