The U.S. Food and Drug Administration (FDA) has approved an extended-release formulation of tofacitinib (Xeljanz XR) “for the treatment of moderate to severe rheumatoid arthritis (RA) in patients who have had an inadequate response or intolerance to methotrexate (MTX)1″according to a press release from Pfizer.

Tofacitinib is an orally available compound belonging to a novel category of drugs, the Janus kinase (JAK) inhibitors. JAKs are crucial second messengers that transmit extracellular cytokine signals. It has been shown that JAK inhibition interrupts intracellular signaling and can suppress immune cell activation and the resulting inflammatory response in T-cell-mediated disorders, such as RA.2

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The new drug application for tofacitinib extended-release tablets is based on data that demonstrated pharmacokinetic equivalence when compared with the standard tofacitinib 5 mg twice-daily dosing. 

Once-daily and twice-daily tofacitinib administrations were both evaluated in 26 healthy volunteers in an open-label, randomized, crossover study.3  Participants were randomly assigned to receive one dose of either the modified-release/extended release (MR) formulation (11 mg once daily), or the previously FDA approved immediate-release (IR) formulation (5 mg twice daily). The primary endpoint was total tofacitinib exposure, as measured by the area under the concentration–time curve (AUC). 

The study found equivalency of single doses of the IR and MR tofacitinib formulations in healthy volunteers, as assessed by attained maximum plasma drug concentrations and time to reach maximum plasma drug concentrations.

“The availability of XELJANZ XR provides physicians with a new treatment option for people with RA who may prefer an oral once-daily treatment,” said Roy Fleischmann, MD, clinical professor in the Department of Internal Medicine at the University of Texas Southwestern Medical Center, in a written press release from Pfizer.1


1.       Pfizer Announces FDA Approval of XELJANZ XR (tofacitinib citrate) Extended-Release Tables, the First and Only Once-Daily Oral JAK Inhibitor Treatment for Rheumatoid Arthritis [news release]. New York, NY: Pfizer Inc. Published February 24, 2016. Accessed February 24, 2016.

2.      Tanaka Y. Recent progress and perspective in JAK inhibitors for rheumatoid arthritis: from bench to bedside. J Biochem. 2015;158(3):173-9; doi: 10.1093/jb/mvv069

3.      Lamba M, Wang R, Fletcher T, et al. HU0143 Pharmacokinetics, Bioavailability and Safety of A Modified Release Once Daily Formulation of Tofacitinib in Healthy Volunteers. Ann Rheum Dis 2014;73:228; doi: 10.1136/annrheumdis-2014-eular.1521