Effect of race and rituximab therapy on RFS in patients presenting with de novo or relapsed iTTP. (A) Overall, Black patients had shorter time to relapse compared with White patients, regardless of treatment. (B) A wearing-off effect of rituximab was found in de novo iTTP, with Black patients seeming to lose the protective effect of rituximab faster than White patients. (C) A pronounced interaction between race and treatment was evident in relapsed iTTP episodes, where RFS more than doubled in White patients with the addition of rituximab. There was no difference in RFS in relapsed iTTP in Black patients, whether treated with rituximab or corticosteroids alone. Minor edits made with Biorender.com.