A Study of F8IL10 Intra-articular Treatment in Rheumatoid Arthritis

The aim of this study is to evaluate the safety of F8IL10 when administered by intra-articular injection and to determine the maximum tolerated dose (MTD) in order to establish the recommended dose (RD) in patients with Reumatoid Arthritis.

Inclusion Criteria: 1. Patients aged ≥18 and ≤80 years. 2. Diagnosis of RA according to ACR/EULAR classification criteria (2010) with a disease duration exceeding 6 months. 3. Presence of arthritis flare(s) suitable for IA injection in a knee, ankle, shoulder, wrist or elbow, despite treatment with stable doses (for at least 3 months) of DMARDs (conventional, biologic, and targeted synthetic) background therapy. 4. No or stable regimens of NSAIDs and/or oral corticosteroid (≤ 10 mg/day; prednisone equivalent) for a period ≥2 weeks prior to screening. 5. All acute toxic effects of any prior therapy must have resolved or returned to classification "mild" (grade 1) according to CTCAE v.5.0. 6. Sufficient hematologic, liver and renal function defined as follows: * Absolute neutrophil count (ANC) ≥1.5 x 109/L, platelets ≥100 x109/L, haemoglobin (Hb) ≥10.0 g/dL. * Alkaline Phosphatase (AP), Alanine Aminotransferase (ALT) and or Aspartate Aminotransferase (AST) ≤3 x Upper Limit of Normal Range (ULN), and total bilirubin ≤2.0 mg/dl (34.2 μmol/L). * Creatinine ≤1.5 ULN or 24 h creatinine clearance ≥50 mL/min. 7. Documented negative TB test (e.g. Quantiferon or equivalent). 8. Documented negative test for HIV-HBV-HCV. For HBV serology, the determination of HBsAg and anti-HBcAg Ab is required. In patients with serology documenting previous exposure to HBV (i.e., anti-HBs Ab with no history of vaccination and/or anti-HBc Ab), negative serum HBV-DNA is required. For HCV, HCV-RNA or HCV antibody test is required. Subjects with a positive test for HCV antibody but no detection of HCV-RNA indicating no ongoing infection are eligible. 9. Sexually active male or female patients of childbearing potential are eligible providing that: * Women of childbearing potential (WOCBP) have a negative pregnancy test performed within 4 weeks prior to treatment start. * WOCBP agree to use, from the screening to 6 months following the last study drug administration, effective method of birth control as applicable per local law that both results in a Pearl index \10 mg/day (prednisone equivalent). Limited use of corticosteroids to treat or prevent acute hypersensitivity reactions is not considered an exclusion criterion. 23. History of alcohol, drug or chemical substance abuse within the 6 months prior to screening. 24. Any condition that in the opinion of the investigator could hamper compliance with the study protocol.