440 CDASI-activity vs IGA scores for dermatomyositis in the lenabasum phase 3 trial

Dermatomyositis(DM) is an autoimmune disease with skin and muscle involvement to varying extents. With its recalcitrance standard-of-care treatments for some, more treatment options are needed. Clinical trials use outcome measures assess activity, such as the CDASI-activity(CDASI-A) or Investigator’s Global Assessment(IGA) scores cutaneous in DM. To be clinically useful, must demonstrate responsiveness change. We evaluated CDASI-A IGA from DM lenabasum phase 3 trial. Our study population included both amyopathic(n=22) classic subtypes(n=145). assessed physician-reported degrees of improvement corresponding mean changes baseline, at weeks 16, 28, 52. Of note, was defined 1) no vs yes 2) if yes, slight moderate major. Mean no, slight, moderate, major include: -4.8; -5.0; -8.6; -12.0 (Week 16), -1.9; -5.5, -8.6, -17.1 28), 0.5; -6.2; -13.4; -17.5 52). 0.03; -0.4; -0.9; -1.1 -0.2; -0.6; -1.3 -0.8; -1.0; -1.7 increased each degree improvement, significantly greater than previous degree(p<0.05). reflected a 1-1.7 point change could only discriminate between improvement. score represents minimal significant This value close 5-point CDASI-A, which consistent research. For IGA, this less 1-point smaller currently used 2-point threshold meaningful novel assessment outcomes investigator’s perspective largest study, suggests preferential future trials.