- 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.