RIST4721 in Subjects with Palmoplantar Pustulosis

INTERVENTION: Product Code: RIST4721 Pharmaceutical Form: Tablet INN or Proposed INN: n/a CAS Number: 1418112‐77‐2 Current Sponsor code: RIST4721 Concentration unit: mg milligram(s) Concentration type: equal Concentration number: 100‐ Pharmaceutical form of the placebo: Tablet Route of administration of the placebo: Oral use CONDITION: Therapeutic area: Diseases [C] ‐ Skin and Connective Tissue Diseases [C17] Palmoplantar Pustulosis (PPP) ; MedDRA version: 21.1 Level: PT Classification code 10050185 Term: Palmoplantar pustulosis System Organ Class: 10040785 ‐ Skin and subcutaneous tissue disorders PRIMARY OUTCOME: Secondary Objective: • Key efficacy secondary endpoints (Please refer "Objectives and Endpoints" section 1.1 Synopsis of the Study Protocol for more details); ; • Additional secondary efficacy endpoints (Please refer "Objectives and Endpoints" section 1.1 Synopsis of the Study Protocol for more details); ; • To assess the safety of RIST4721 in this population (Please refer "Objectives and Endpoints" section 1.1 Synopsis of the Study Protocol for more details); ; Main Objective: To evaluate the efficacy of RIST4721 in the treatment of subjects with moderate to severe PPP Primary end point(s): Proportion of subjects achieving a 50% reduction in PPPASI score at Week 12 Timepoint(s) of evaluation of this end point: Week 12 SECONDARY OUTCOME: Secondary end point(s): Key Secondary:; • Proportion of subjects achieving Palmoplantar Pustulosis Physician Global Assessment (PPPGA) of 0 or 1 at Week 12; • Proportion of subjects achieving 75% reduction in PPPASI score at Week 12; ; Additional secondary efficacy endpoints: ; • Absolute change from baseline in PPPGA at Week 12; • Absolute change from baseline in PPPASI at Week 12; ; To assess the safety of RIST4721 in this population: ; •Incidence of TEAEs and SAEs; • Change from Baseline in clinical laboratory parameters, electrocardiogram (ECG) parameters, and vital signs; ; Timepoint(s) of evaluation of this end point: Week 12 INCLUSION CRITERIA: Age and Sex 1. Male or female subject aged =18 years and < 75 years of age at the time of consent. Type of Subject and Disease Characteristics 2. A physician‐confirmed diagnosis of PPP (sterile, macroscopically visible pustules on the palms and/or soles) for at least 6 months prior to screening without evidence of infection on palms and soles. 3. Moderate or severe PPP, as defined by PPPASI =12 and PPPGA =3 at screening and confirmed by central photographic assessment at screening. Subjects must have an area involvement of at least 30% on 2 palmoplantar surfaces or at least 60% on one palmoplantar surface. 4. At randomization visit, all of the following must be met: • PPPASI score must be = 90% of the score at screening and PPPASI score of =12; • PPPGA score must be =3 and = the score at screening; • PPPASI subscore of pustules/vesicles on at least one palm or sole =2. 5. Candidate for systemic therapy, defined as having PPP inadeq