Not everyone agrees that MRI is necessary to characterize joint structure. Samumed’s Yazici argued that if a molecule has a meaningful effect size, X-ray should be more than suitable for measuring the benefit. “In RA, if you look at all the approval packages, there’s nothing about MRIs. It is all X-rays because if you have a drug that has enough efficacy, you can see it on the X-ray,” he said.