Phase 1b Study of PLX5622 in Rheumatoid Arthritis Patients Who Are Receiving Methotrexate

Inclusion Criteria

• •Male or female patients ≥ 18 years old with a diagnosis of rheumatoid arthritis by ACR criteria for ≥ 3 months.
• •Prior to Day 1, patients must be on oral or subcutaneous methotrexate (≥10 mg/week and ≤ 25 mg/week) for at least 12 weeks (with a stable dose for at least 4 weeks) and folate (≥ 5 mg/week) for at least 6 weeks, and willing to continue on this regimen for the duration of the study.
• •Adequate hematologic, hepatic, and renal function (absolute neutrophil count ≥ 1.5 X 109/L, Hgb \> 9 g/dL, platelet count ≥ 100 X 109/L, AST/ALT WNL, albumin ≥ 3 g/dL, calculated CrCl\>60 mL/min using Cockcroft-Gault formula).
• •Women of child-bearing potential must have a negative pregnancy test within 7 days prior to initiation of dosing with study drug and must agree to use a double barrier method of birth control from the time of the negative pregnancy test up to 30 days after the last dose of study drug. Women of nonchildbearing potential may be included if they are either surgically sterile or have been postmenopausal for ≥ 1 year.
• •Fertile men must agree to use an acceptable method of birth control while on study drug. Acceptable methods of contraception must include either abstinence from the first dose of study drug through 4 weeks after the last dose of study drug, or use of a condom with instructions to the female partner of child-bearing potential to also be protected as above.
• •Willing and able to provide written informed consent prior to any study-related procedures and to comply with all study requirements.