Study of an Anti-TLR4 mAb in Rheumatoid Arthritis

Inclusion Criteria: * Male and female patients * Age \>= 18 years old * BMI: \< 30 and \> 18 * Diagnosis of RA according to 2010 ACR/EULAR criteria and with a disease duration of at least 6 months since diagnosis * Patient must present with active RA, characterized by at least 6 swollen joints out of 66 assessed and 6 tender joints out of 68 assessed and by the presence of synovitis (measured by ultrasound) in at least one of the 6 swollen joints * C-reactive protein (CRP) level \> 0.7 mg/dL or if the CRP level is between 0.3 mg/dL and 0.7 mg/dL (included) then patient must also present an ESR \> 30mm/hr * Patients must have received MTX treatment for at least 3 months and have been on a stable dose of MTX for at least 6 weeks prior to start of screening * ACPA-positive RA patients * Women must be postmenopausal (\> 12 months without menses) or surgically sterile or using two effective contraception methods for at least 4 weeks prior to the randomization date and agree to continue contraception for the duration of their participation in the study (until the end of follow up period) * Sexually active male patients must use a barrier method of contraception during the course of the study (and until the end of the follow up period) * Patients must give written informed consent for study participation Exclusion Criteria: * A documented history of an autoimmune disease other than RA by ACR classification, or Sjögren syndrome * Administration of cytotoxic drugs and immune suppressants (other than MTX) within 3 months prior to screening * Previous multiple administrations of any biological DMARD or targeted synthetic DMARD * Known primary immunodeficiency * Pregnant or breastfeeding women * Suspicion of active or latent tuberculosis * HIV, HCV, HBV infection * Infection reported during screening not recovered 72h prior to first dose * History of anaphylactic reactions to any protein therapeutics or excipients * Any history of malignancy, excluding cured basal or squamous cell carcinoma of the skin, or cervical in situ carcinoma * Clinically significant cardiac disease requiring medication, such as congestive heart failure, unstable angina, myocardial infarction within 6 months prior to randomization * Moderate to severe renal insufficiency, clinically relevant liver function test abnormalities or pancytopenia * Major psychiatric or neurological disorder