Efficacy and Safety Study of CC-292 Versus Placebo as Co-therapy With Methotrexate in Active Rheumatoid Arthritis

Percentage of participants with an American College of Rheumatology ≥20% (ACR20) response. A participant is a responder if the following 3 criteria for improvement from Baseline are met: • ≥ 20% improvement in 68 tender joint count; • ≥ 20% improvement in 66 swollen joint count; and • ≥ 20% improvement in at least 3 of the 5 following parameters: o Patient's assessment of pain (measured on a 100 mm visual analog scale [VAS]); o Patient's global assessment of disease activity (measured on a 100 mm VAS); o Physician's global assessment of disease activity (measured on a 100 mm VAS); o Patient's self-assessment of physical function (Health Assessment Questionnaire - Disability Index (HAQ-DI)); o C-Reactive Protein

Safety and tolerability of CC-292 compared with placebo in subjects on a background of stable MTX therapy. An adverse event (AE) is any noxious, unintended, or untoward medical occurrence that may appear or worsen in a subject during the course of a study. It may be a new intercurrent illness, a worsening concomitant illness, an injury, or any concomitant impairment of the subject's health, including laboratory test values (as specified by the criteria below), regardless of etiology. Any worsening (ie, any clinically significant adverse change in the frequency or intensity of a preexisting condition) should be considered an AE.

Percentage of participants with an American College of Rheumatology ≥50% (ACR50) response. A participant is a responder if the following 3 criteria for improvement from Baseline are met:

• ≥ 50% improvement in 68 tender joint count;
• ≥ 50% improvement in 66 swollen joint count; and
• ≥ 50% improvement in at least 3 of the 5 following parameters:

• Patient's assessment of pain (measured on a 100 mm visual analog scale [VAS]);
• Patient's global assessment of disease activity (measured on a 100 mm VAS);
• Physician's global assessment of disease activity (measured on a 100 mm VAS);
• Patient's self-assessment of physical function (Health Assessment Questionnaire - Disability Index (HAQ-DI));
• C-Reactive Protein.

Percentage of participants with an American College of Rheumatology ≥70% (ACR70) response. A participant is a responder if the following 3 criteria for improvement from Baseline are met:

• ≥ 70% improvement in 68 tender joint count;
• ≥ 70% improvement in 66 swollen joint count; and
• ≥ 70% improvement in at least 3 of the 5 following parameters:

• Patient's assessment of pain (measured on a 100 mm visual analog scale [VAS]);
• Patient's global assessment of disease activity (measured on a 100 mm VAS);
• Physician's global assessment of disease activity (measured on a 100 mm VAS);
• Patient's self-assessment of physical function (Health Assessment Questionnaire - Disability Index (HAQ-DI));
• C-Reactive Protein.