XBiotech Inc. announced additional data analysis of its Phase 2 study evaluating XBiotech's True Human antibody, MABp1, as a treatment for Hidradenitis Suppurativa (HS). The study achieved its primary endpoint, showing significant treatment benefit using the HiSCR endpoint, which is the method used in the development of the only therapy currently approved for the treatment of HS. However, other methods of evaluating disease severity and response to treatment have been proposed. The iHS4 scoring system has recently been proposed as a new measure of HS disease severity 1 but its usefulness as a clinical measure has not been extensively studied. Investigators used data from the Phase 2 study to evaluate the iHS4 scoring method to see how it correlates with the HiSCR findings. The data presented are thus a retrospective analysis using the iHS4 score for all 20 patients who were randomized to receive either placebo or MABp1 therapy in the Phase 2 double-blind study. At least 30% decrease of the iHS4 score from the baseline at week 12 was associated with 100% sensitivity for positive HiSCR score (the efficacy measure used in the phase 2 study). This change was found in one (10%) and in four (40%) patients allocated to placebo and MABp1, respectively (p= 0.046).