Pfizer Inc. received US FDA approval for XELJANZ (tofacitinib citrate) 5mg twice daily for the treatment of adults with moderately to severely active rheumatoid arthritis who have had an inadequate response or intolerance to methotrexate. XELJANZ may be used as monotherapy or in combination with methotrexate or other non-biologic disease-modifying antirheumatic drugs. XELJANZ is approved as a second-line medicine for RA, which means treatment with a biologic is not required before taking XELJANZ. XELJANZ is specifically designed to inhibit the JAK pathways, which are signaling pathways inside the cell that play an important role in the inflammation involved in rheumatoid arthritis. Tofacitinib is currently under investigation for psoriasis as well.