- Have been tolerating concomitant methotrexate (oral or subcutaneous) for at least 3 months prior to screening and on a stable dose between 10-25 mg per week for at least 6 weeks prior to the first study dose. The route of administration must also be stable. Use of methotrexate dose of 25-50 mg every 2 weeks is also acceptable. (Other DMARDs taken concomitantly with methotrexate are not allowed. Those subjects concomitantly receiving additional DMARDs with methotrexate may enter the study by stopping the additional DMARD at least 4 weeks prior to first study dose).