TY - JOUR T1 - Response to: ‘“MAINRITSAN2-the future”, with some doubts!’ by Chattopadhyay <em>et al</em> JF - Annals of the Rheumatic Diseases JO - Ann Rheum Dis SP - e140 LP - e140 DO - 10.1136/annrheumdis-2018-214516 VL - 78 IS - 12 AU - Pierre Charles AU - Loic Guillevin Y1 - 2019/12/01 UR - http://ard.bmj.com/content/78/12/e140.abstract N2 - We would like to thank Chattopadhyay et al 1 for their comments regarding our paper.2 The MAINtenance of Remission Using RITuximab in Systemic ANCA-associated Vasculitis (MAINRITSAN2) trial was designed in 2011. At that time, the MAINRITSAN trial results were not yet available, which explains why a conservative hypothesis was used to calculate the sample size. Given the low relapse rate (9.9%) observed with rituximab maintenance therapy for antineutrophil cytoplasm antibody (ANCA)-associated vasculitides (AAVs), our study was underpowered to detect an absolute relapse rate difference of 7%. However, a post-hoc power calculation is not necessary to reach this conclusion.3 The individually tailored group had more relapses … ER -