CC-292 is an oral agent that is under clinical development for the treatment of rheumatoid arthritis an autoimmune inflammatory disorder.

This study will test the clinical effectiveness and safety of an orally (PO) administered dose of CC-292 compared to placebo in US female patients currently on background Methotrexate (MTX) with active Rheumatoid Arthritis (RA

This is a Phase 2a, multicenter, randomized, double-blind, placebo-controlled, proof-of-concept study to determine the efficacy and safety of CC-292 (375 mg PO daily) on a stable background of MTX therapy in female subjects with active RA.

Approximately 80 female subjects with active RA will be randomized 1:1 into two dose groups: active CC-292 (375 mg PO daily) or identically-appearing placebo capsules for 4 weeks

Inclusion Criteria:

• Female between 18 and 80 years of age (inclusive) at the time of signing the informed consent.
• Must meet the 2010 ACR/EULAR Classification Criteria for RA (Appendix A), have RA for at least 6 months and must continue to have active RA at the time of randomization despite at least 3 months of treatment with stable doses of MTX (7.5 to 25 mg/week oral or parenteral) for at least 4 weeks prior to randomization.
• Must have been treated with MTX for at least 3 months prior to randomization, and must be on a stable dose between 7.5 and 25 mg/week (PO or parenteral, not both) for at least 4 weeks prior to randomization. Subjects will be required to maintain their stable dose through Day 28/Week 4 of the study. Oral folate supplementation is required with a minimum dose of 5 mg/week (ie, folic acid) while the subject is taking MTX. Leucovorin may be used instead of folic acid and may be dosed up to 10 mg/week orally.
• Sulfasalazine is allowed as a concomitant medication, however, subject must be on a stable dose for at least 4 weeks prior to randomization and through Day 28/Week 4 of the study.
• Hydroxychloroquine or chloroquine is allowed as concomitant medications, however, subject must be on a stable dose for at least 4 weeks prior to randomization and through Day 28/Week 4 of the study.
• Modification of Diet in Renal Disease formula (MDRD) estimated glomerular filtration rate (MDRD eGFR) ≥ 60 mL/min/1.73m2+

Exclusion Criteria:

• Male subjects
• Any condition that could affect CC-292 absorption, including gastric restrictions, bariatric surgery, such as gastric bypass, and clinical conditions that are associated with decreased intragastric acid production such as acid pernicious anemia.
• Currently using treatment with DMARDs (other than sulfasalazine, hydroxychloroquine or chloroquine and MTX), including biologics. Previous use is only allowed after adequate washout (4 weeks or 5 half-lives, whichever is longer) prior to randomization.
• Previous treatment with any cell depleting therapies, including investigational agents (eg, CAMPATH, anti-CD4, anti-CD5, anti-CD3, anti-CD19 and anti-CD20) within 6 months of screening.
• Treatment with intravenous gamma globulin, plasmapheresis or Prosorba® column within 2 weeks prior to randomization.
• Intra-articular or parenteral corticosteroids are not allowed within 2 weeks prior to randomization.