A Study to Evaluate the Efficacy and Safety of MLTA3698A in Combination With a Disease-Modifying Anti-Rheumatic Drug (DMARD) Compared With Adalimumab in Combination With a DMARD in Patients With Active Rheumatoid Arthritis

• Baseline change in disease activity, assessed as the Disease Activity Score (DAS28) and erythrocyte sedimentation rate, or DAS28-(4)-ESR [ Time Frame: Day 85 ] [ Designated as safety issue: No ]
• Incidence and severity of adverse events and clinical laboratory abnormalities as a measure of safety and tolerability of MLTA3698A [ Time Frame: Length of study (through Day 85) ] [ Designated as safety issue: No ]

• ACR20 response rate (the proportion of patients in each treatment group meeting the American College of Rheumatology 20% responder criteria [ACR20] for their average response ) [ Time Frame: Day 85 ] [ Designated as safety issue: No ]
• ACR50 response rate (the proportion of patients in each treatment group meeting the American College of Rheumatology 50% responder criteria [ACR50] for their average response ) [ Time Frame: Day 85 ] [ Designated as safety issue: No ]
• ACR70 response rate (the proportion of patients in each treatment group meeting the American College of Rheumatology 70% responder criteria [ACR70] for their average response) [ Time Frame: Day 85 ] [ Designated as safety issue: No ]
• Tender joint count [ Time Frame: Day 85 ] [ Designated as safety issue: No ]
• Swollen joint count [ Time Frame: Day 85 ] [ Designated as safety issue: No ]
• Investigator Global Assessment of Disease Activity [ Time Frame: Day 85 ] [ Designated as safety issue: No ]
• Patient Global Assessment of Pain and Disease Activity [ Time Frame: Day 85 ] [ Designated as safety issue: No ]
• Health Assessment Questionnaire Disability Index [ Time Frame: Day 85 ] [ Designated as safety issue: No ]
• Patient's Global Health or Short Form Health Survey (SF-36) [ Time Frame: Day 85 ] [ Designated as safety issue: No ]
• European League Against Rheumatism response rate [ Time Frame: Day 85 ] [ Designated as safety issue: No ]
• Serum C-reactive protein levels [ Time Frame: Day 85 ] [ Designated as safety issue: No ]
• Erythrocyte sedimentation rate [ Time Frame: Day 85 ] [ Designated as safety issue: No ]

This is a Phase II, randomized, double-blind, placebo-controlled, parallel-group, multicenter study enrolling patients with active rheumatoid arthritis (RA).

• Drug: adalimumab
  Subcutaneous repeating dose
• Drug: leflunomide
  Stable dose if not on methotrexate
• Drug: methotrexate
  Stable dose if not on leflunomide
• Drug: MLTA3698A
  Subcutaneous repeating dose
• Drug: placebo
  Subcutaneous repeating dose

• Experimental: A
  Interventions:

  • Drug: leflunomide
  • Drug: methotrexate
  • Drug: MLTA3698A
• Active Comparator: B
  Interventions:

  • Drug: adalimumab
  • Drug: leflunomide
  • Drug: methotrexate
  • Drug: placebo
• Placebo Comparator: C
  Interventions:

  • Drug: leflunomide
  • Drug: methotrexate
  • Drug: placebo

Inclusion Criteria:

• Diagnosis of RA according to the 1987 revised ACR Criteria for the Classification of RA for at least 6 months prior to screening
• Positive for rheumatoid factor or anti-cyclic citrullinated peptide (CCP) antibody, or both
• Active disease, defined as: CRP >= 1.0 mg/dL; swollen joint count >= 6 (66 joint count); tender joint count >= 6 (68 joint count)
• Previous inadequate clinical response to at least one disease-modifying anti-rheumatic drug (DMARD) consisting of either methotrexate (MTX) or leflunomide (LFU)
• For patients currently receiving corticosteroids: Treatment at a stable dose during last 4 weeks prior to screening
• For patients currently receiving non-steroidal anti-inflammatory drugs (NSAIDs): Treatment at a stable dose during last 4 weeks prior to screening
• For patients currently receiving sulfasalazine or anti-malarials: Treatment initiated and continued for at least the last 6 months prior to screening and on a stable dose
• For patients of reproductive potential (males and females): Willing to use a highly effective birth control method for the duration of the study according to local guidelines

Exclusion Criteria:

• Pregnant, planning to become pregnant during the study, or breastfeeding
• Clinically significant abnormal laboratory values or abnormal ECG or vital signs
• History of anaphylactic reactions
• Rheumatic autoimmune disease other than RA, or significant systemic involvement secondary to RA (including but not limited to vasculitis, pulmonary fibrosis, or Felty's syndrome), however patients with secondary Sjogren's syndrome are eligible for the study
• History of or current inflammatory joint disease other than RA (e.g., gout, reactive arthritis, psoriatic arthritis, seronegative spondyloarthritis, Lyme disease) or other systemic autoimmune disorder (e.g., systemic lupus erythematosus, inflammatory bowel disease, scleroderma, inflammatory myopathy, mixed connective tissue disease, or other overlap syndrome)
• Current or recent (within 4 weeks prior to screening) infection, including signs, symptoms or serology of any infection, including HIV, hepatitis B or C, tuberculosis
• Administration of a live, attenuated vaccine within 1 month before dosing or anticipation that such a live attenuated vaccine will be required during the study
• Previous treatment with anti-TNF biologics or other biologic agents, including anti-CD20-directed therapy (e.g. rituximab), anti-IL6-directed therapy (e.g. tocilizumab), or T cell-directed therapy (e.g. abatacept)