When the first JAK (janus kinase) inhibitor, Xeljanz (tofacitinib, Pfizer), was approved for rheumatoid arthritis (RA) in 2012, many thought it would quickly eat up a large piece of the market. Sales since then, however, have been disappointing. Some believe this has to do with its initial failure to get approved in Europe, while others believe that there were lingering safety issues that were not recognized in the label. Regardless, sales have continued to climb.
Six months ago, Xeljanz hit the ulcerative colitis (UC) scene –the first JAK to do so. Compared to the current standard of care, Entyvio (vedolizumab, Takeda), Xeljanz shows significant improvement in both efficacy and convenience, demonstrating that having an oral route of administration could be a game-changer in the world of ulcerative colitis.
Now that Xeljanz has an EMA approval in RA (as of March 2017) and more long-term safety data has been released, we expect it to quickly eat up a corner of the UC market. With four other JAKs in late development, this class could pose a serious threat to anyone else hoping to compete in ulcerative colitis.