1.- Positive for human immunodeficiency virus (HIV). 2.- RA in mild or severe activity, according to the DAS28 index. 3.- Have <2 swollen joints. 4.- Age < 19 or > 80 years. 5.- CRP value < 5.10 mg/dL 6.- Previous dose of MTX below 12.5 mg or less than 6 months of treatment without being considered refractory to the product. 7.- Stable dose of prednisone > 10.0 mg during the previous eight weeks. 8.- No use of prednisone in the last 8 weeks prior to inclusion in the study. 9.- Positive serology for Hepatitis B or Hepatitis C 10.- Value of complementary clinical laboratory outside the normal range and clinically relevant. 11.- Previous treatment with Jusvinza for any reason or illness. 12.- Having participated as a patient included in phase I or phase II studies. 13.- Positive serology for SARS-CoV-2 (as long as it is considered an active pandemic and involves differentiated management of the sick subject). 14.- Pregnancy, puerperium or lactation period. 15.- Female patient of childbearing age who does not use effective contraceptive methods (intrauterine devices, barrier methods or tubal ligation) or male patient who does not use effective methods to prevent procreation (condom or vasectomy). 16.- Male patient with a pregnant female sexual partner. 17.- Treatment with another investigational product at the time of inclusion. 18.- Previous treatment with another biological therapy. 19.- Complicated RA (systemic vasculitis, myocarditis, pericardial effusion with hemodynamic compromise, pleural effusion with respiratory compromise, antiphospholipid syndrome, renal amyloidosis, autoimmune hepatitis, digestive bleeding). 20.- Other rheumatic diseases of autoimmune origin that affect the osteomyoarticular system. 21.- Consumption greater than ¼ bottle of rum or a bottle of wine or three beers, with a frequency greater than three times a week. 22.- Drug-dependent patient. 23.- Concomitant chronic disease such as chronic renal failure (CRF), nephrotic syndrome, acute or chronic liver disease, chronic obstructive pulmonary disease (COPD), decompensated ischemic heart disease, hypertensive encephalopathy, cerebrovascular disease, diabetes mellitus with metabolic decompensation, acute peripheral arterial insufficiency and complications in other organs such as the kidney (Kinmestiel – Wilson, IRC, necrotizing papillitis). 24.- Feverish states due to severe infectious or septic processes, not associated with the evolution of the disease. 25.- Haematological disease. (Acute or chronic leukosis, lymphoma, plasma cell dyscrasias, coagulation disorders) 26.- Malignant neoplasm. 27.- Congenital or acquired immunodeficiency at the time of inclusion. 28.- Psychological, intellectual or sensory dysfunction that may prevent understanding and compliance with the requirements of the study according to the criteria of the clinical investigator.