Also Known As: Tofacitinib, Jakvinus, Xeljanz, tasocitinib
Tofacitinib (trade names Xeljanz and Jakvinus, formerly tasocitinib, CP-690550) is a drugof the janus kinase (JAK) inhibitor class, discovered and developed by Pfizer. It is currently approved for the treatment of rheumatoid arthritis (RA) in the United States and Russia, and is being studied for treatment of psoriasis, inflammatory bowel disease, and other immunological diseases, as well as for the prevention of organ transplant rejection. Tofacitinib was not approved by the European regulatory agencies because of concerns over efficacy and safety.
It is an inhibitor of the enzyme janus kinase 3 (JAK3), which means that it interferes with the JAK-STAT signaling pathway, which transmits extracellular information into the cell nucleus, influencingDNA transcription.
Recently it has been shown in a murine model of established arthritis that tofacitinib rapidly improved disease by inhibiting the production of inflammatory mediators and suppressing STAT1-dependent genes in joint tissue. This efficacy in this disease model correlated with the inhibition of both JAK1 and 3 signaling pathways, suggesting that tofacitinib may exert therapeutic benefit via pathways that are not exclusive to inhibition of JAK3.
As of April 2011 a phase III trial for psoriasis is under way.
Combination with methotrexate
Tofacitinib is taken in combination with or without methotrexate.
In June 2014, scientists at Yale have successfully treated a male patient afflicted with alopecia universalis. The patient was able to grow a full head of hair, eyebrows, eyelashes, facial, armpit and other hair. No side effects where reported in the study.