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

• RIST4721 (Drug): RIST4721 tablets, 100 mg are blue, oval, biconvex film-coated tablets
• Placebo (Drug): Matching placebo

Primary outcomes

• Proportion of Subjects Achieving a 50% Reduction in PPPASI Score [Baseline to Week 12]: 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).

Secondary outcomes

• Absolute Change From Baseline in PPPGA [Baseline to Week 12]
• Absolute Change From Baseline in PPPASI [Baseline to Week 12]

Sex: All, ages: 18 Years to 74 Years

Inclusion Criteria:

* At least 6 months history of moderate or severe PPP, as defined by PPPASI ≥12 and PPPGA ≥3 at screening
* Males and females must be willing to use birth control as indicated

Exclusion Criteria:

* Moderate to severe psoriasis covering ≥10% of total body surface area (BSA) at screening
* Breastfeeding or pregnant
* Known immunodeficiency or subject is immunocompromised
* Active/latent infection with HBV, HCV, HIV, SARS-CoV-2 or TB
* Any topical medications for PPP excluding emollients within two weeks of randomization and systemic therapies (including phototherapy) within 4 weeks of randomization

Participant flow

Outcome results

• Proportion of Subjects Achieving a 50% Reduction in PPPASI Score (Primary), Count of participants, Participants: RIST4721 400 mg 6; RIST4721 200 mg 3; Placebo 5
• Absolute Change From Baseline in PPPGA (Secondary)
• Absolute Change From Baseline in PPPASI (Secondary)

Adverse events

Time frame: Baseline through end of Week 12 (blinded treatment) and up to 4 weeks of follow-up.

Serious adverse events by term

Other adverse events by term

6 more terms not shown.

• Study Protocol (PDF, 2022-04-05)
• Statistical Analysis Plan (PDF, 2023-02-17)