ACR20 response rates. ACR20 response rates. ACR20 response rates based on non-responder imputation (NRI) for the 120/Q4W, 90/Q2W and placebo groups over 24 weeks of treatment. Response rates are based on the ITT population. ACR20=20% improvement in American College of Rheumatology criteria; 120/Q4W=120 mg subcutaneous (SQ) tabalumab injection every 4 weeks; 90/Q2W=90 mg SQ tabalumab injection every 2 weeks. Michael Schiff et al. RMD Open 2015;1:e000037 Copyright © BMJ Publishing Group & EULAR. All rights reserved.