A Phase 2b Study to Evaluate RIST4721 in Palmoplantar Pustulosis (PPP)

Proportion of Subjects Achieving a 50% Reduction in PPPASI Score

In the Palmoplantar Pustulosis Psoriasis Area and Severity Index (PPPASI), the left palm, right palm, left foot, and right foot are assessed based on 3 target symptoms: erythema, desquamation (scaling), and pustules, as seen on the day of the examination. The severity of each sign is assessed using a 5-point scale (0 = not present, 1 = slight, 3 = moderate, 4 = severe, 5 = very severe). The affected area within a given anatomic site (left palm, right palm, left foot, and right foot) is estimated as a percentage of the total area of that anatomic site and assigned a numerical value according to the degree of PPP involvement (0 = no involvement, 2 = 10 to less than 30% involvement, 3 = 30 to less than 50% involvement, 4 = 50 to less than 70% involvement, 5 = 70 to less than 90% involvement, 6 = 90 to less than 100% involvement). PPPASI score for palms and soles is obtained using a formula and can vary from 0 (absence of disease) to 72 (most severe disease).

Time frame: Baseline to Week 12