Overview A Drug Interaction Study to Evaluate the Pharmacokinetics of ASP015K and Methotrexate in Patients With Rheumatoid Arthritis Status: Completed Trial end date: 2010-03-25 Target enrollment: Participant gender: Summary A drug interaction study to evaluate the effect of ASP015K (twice daily) on the pharmacokinetics (PK) of once weekly oral methotrexate (MTX). Phase: Phase 1 Details Lead Sponsor: Astellas Pharma IncTreatments: MethotrexatePeficitinib