XELJANZ has been shown to be effective in slowing the progression of joint damage. In a clinical trial at 6 months, XELJANZ reduced joint damage progression better than methotrexate.
In the ORAL Start Study, XELJANZ patients hadn't taken methotrexate prior to the study. However, XELJANZ is only approved for use in patients for whom methotrexate did not work well. At 6 months, XELJANZ patients got worse by 0.2 units of change on the modified Total Sharp Score (mTSS) scale, while patients taking methotrexate worsened by 0.8. mTSS measures joint damage progression in selected joints of the hands and feet. The higher the amount of change in the mTSS, the more joint damage has progressed.
In the ORAL Scan Study, patients who took XELJANZ and methotrexate had less progression of joint damage after 6 months (0.1) than those who took a placebo and methotrexate (0.5). However, the possibility was high enough that the difference between treatments may have been due to chance alone and not due to XELJANZ, so the results were not considered significant.