Ruxolitinib in Previously Treated Idiopathic Multicentric Castleman Disease

There is currently no agreed-on recommended treatment for iMCD patients whose disease does not respond to siltuximab or tocilizumab, which is a major challenge for patients. The purpose of this study is to find out the effects of a study drug, ruxolitinib (also called Jakafi), in these patients. This study looks at how well the drug is tolerated by participants and its effects on participants' iMCD symptoms.