A Randomized, Double-Blind, Placebo-Controlled, Phase 2a Study to Evaluate the Efficacy and Safety of RIST4721 in Subjects with Palmoplantar Pustulosis

Inclusion Criteria:

• At least a 6-month history of PPP as defined by the presence of pustules on palms and/or soles, but without evidence of infection on palms and soles
• Moderate or severe PPP, as defined by Palmoplantar Pustulosis Psoriasis Area and Severity Index (PPPASI) ≥8 and Palmoplantar Pustulosis Physician Global Assessment (PPPGA) ≥3 at Day -1, and a minimum of 8 fresh pustules at screening (fresh pustule count on both right/left palms and soles) and 20 fresh pustules at Day -1 (fresh pustule count on both right/left palms and soles)
• Males and females must be willing to use birth control as indicated

Exclusion Criteria:

• Moderate to severe psoriasis, as defined by plaque psoriasis covering ≥10% of total Body Surface Area (BSA) at Day -1
• Subject is known to have an immune deficiency or is immunocompromised
• Positive test for hepatitis, human immunodeficiency virus (HIV) or tuberculosis
• Use of topical therapies for PPP within 2 weeks of Day -1 and/or systemic therapies for PPP within 4 weeks

All subjects who were randomized to either RIST4721 or Placebo

From ICF signature to end of study participation (approximately 73 days)

Double-blind