This study aims to compare longitudinally the effect of adalimumab plus methotrexate (MTX) versus MTX monotherapy on cartilage GAG content, reflected by Delayed Gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) index, in patients with early progressive rheumatoid arthritis (RA), who had not previously received any Disease modifying antirheumatic drug (DMARD) or biologic treatment.

Patients will be randomly assigned to either adalimumab q2w plus oral MTX qw combination therapy or oral MTX qw monotherapy plus placebo subcutaneous (SC) q2w in a ration 2:1. To maintain blinding, matching placebo SC injections will be dispensed q2w to the MTX monotherapy group. All subjects will receive open-label MTX 15 mg qw as oral tablets. All subjects will take approximately 5 mg weekly dietary supplement of oral folate throughout the study on any day beginning 48 hours after ingestion of their oral study medication. Defined as standard therapy oral folate supplementation will be taken in a single dose 24-48 h after MTX therapy.

Inclusion Criteria:

• Subject has a diagnosis of early RA (ERA) fulfilling the 2010 American college of rheumatology (ACR) criteria for classification of RA
• Disease duration less than 12 months from symptoms onset.

Exclusion Criteria:

• Subject has previous exposure to any systemic biologic therapy (e.g. abatacept, tocilizumab) including anti-Tumor necrosis factor (TNF therapy) (e.g., infliximab, golimumab, certolizumab pegol, etanercept) including adalimumab.