A Study to Evaluate the Efficacy and Safety of Imsidolimab (ANB019) in Adults With Palmoplantar Pustulosis

• Imsidolimab (Biological), also known as ANB019: Administered by subcutaneous injection once a month
• Placebo (Drug): Administered by subcutaneous injection once a month

Primary outcomes

• Change From Baseline in Palmoplantar Pustulosis Psoriasis Area Severity Index (PPPASI) [Baseline to Week 16]: The Palmoplantar Pustulosis Area and Severity Index (PPPASI) is used to assess the severity of palmoplantar pustulosis lesions and their response to therapy. The glabrous skin of both palms and both soles are assessed for erythema, pustules, and desquamation (scaling), each on a scale from 0 (none) to 4 (very severe). The area affected of each palm and sole is scored from 0 (0%) to 6 (90-100%). Scores for the 3 characteristics of PPP are summed and adjusted for the area affected, and the scores for each palm and sole are added to calculate the total score. The PPPASI total score ranges from 0 to 72. A higher score indicates more severe disease, and a negative change from Baseline indicates improvement.
• Number of Participants With Treatment-emergent Adverse Events (TEAEs) [From first dose of any study drug to Week 24]: Clinical safety was evaluated by reporting incidence of adverse events up to week 24. TEAEs are defined as new events that occured during or after first dose of study drug or any event that worsens after first dose of study drug. A serious AE (SAE) is defined as any untoward medical occurrence that resulted in death, was life-threatening, resulted in persistent disability/incapacity, was a congenital anomaly/birth defect, or an important medical event that may jeopardize the participant or require medical or surgical intervention to prevent one of the outcomes listed above. Severity was assessed by the Investigator as mild (easily tolerated, causing minimal discomfort and not interfering with everyday activities), moderate (causes sufficient discomfort and interferes with normal everyday activities) or severe (prevents normal everyday activities). The Investigator assessed the relationship between study treatment and each AE based on clinical judgement.

Secondary outcomes

• Percentage of Participants Who Achieved 50% Reduction (Improvement) From Baseline in Palmoplantar Pustulosis Psoriasis Area Severity Index Score (PPPASI 50) [Baseline to Week 16]: The Palmoplantar Pustulosis Area and Severity Index (PPPASI) is used to assess the severity of palmoplantar pustulosis lesions and their response to therapy. The glabrous skin of both palms and both soles are assessed for erythema, pustules, and desquamation (scaling), each on a scale from 0 (none) to 4 (very severe). The area affected of each palm and sole is scored from 0 (0%) to 6 (90-100%). Scores for the 3 characteristics of PPP are summed and adjusted for the area affected, and the scores for each palm and sole are added to calculate the total score. The PPPASI total score ranges from 0 to 72. A higher score indicates more severe disease.
• Percentage of Participants Who Achieved a Clear or Almost Clear Palmoplantar Pustulosis Investigator's Global Assessment (PPPIGA) Score at Week 16 [Week 16]: The Investigator rated the severity of participants' disease on the following 5-point scale: * 0: Clear - No signs of palmoplantar pustulosis; no scaling or crusts or pustules remain; * 1: Almost clear - Slight scaling and/or erythema and/or slight crusts; very few (yellow) and/or old (brown) pustules; * 2: Mild - Scaling and/or erythema and/or crusts; visible new (yellow) and/or old (brown) pustules of limited number and extent; * 3: Moderate - Prominent scaling and/or erythema and/or crusting; prominent new (yellow) and/or old (brown) pustules covering most of the area involved; * 4: Severe - Severe scaling and/or erythema and/or crusting; numerous new (yellow) and/or old (brown) pustules with / without major confluence, covering the entire area of at least 2 palmoplantar sites.

Sex: All, ages: 18 Years to 75 Years

Inclusion Criteria:

* Clinically confirmed diagnosis of PPP
* Disease duration of at least 6 months prior to screening
* Present with active pustules on palms or/and soles at screening

Exclusion Criteria:

* Any other ongoing inflammatory disease that interfere with the investigator's ability to evaluate the subject's response to therapy
* History of recurrent or active/serious infection
* Ongoing use of psoriasis prohibited medication

Other protocol-defined inclusion/exclusion criteria may apply

Participant flow

Outcome results

• Change From Baseline in Palmoplantar Pustulosis Psoriasis Area Severity Index (PPPASI) (Primary), Least squares mean, score on a scale: Placebo -6.0 +/- 1.48; Imsidolimab -6.1 +/- 1.46 (p 0.944)
• Number of Participants With Treatment-emergent Adverse Events (TEAEs) (Primary), Count of participants, Participants: Placebo 20; Imsidolimab 21
• Percentage of Participants Who Achieved 50% Reduction (Improvement) From Baseline in Palmoplantar Pustulosis Psoriasis Area Severity Index Score (PPPASI 50) (Secondary), Number, percentage of participants: Placebo 50.0 (29.12 to 70.88); Imsidolimab 45.8 (25.55 to 67.18)
• Percentage of Participants Who Achieved a Clear or Almost Clear Palmoplantar Pustulosis Investigator's Global Assessment (PPPIGA) Score at Week 16 (Secondary), Number, percentage of participants: Placebo 12.5 (2.66 to 32.36); Imsidolimab 20.8 (7.13 to 42.15)

Adverse events

Time frame: From first dose of any study drug to Week 24

Serious adverse events by term

Other adverse events by term

1 more terms not shown.

• Study Protocol (PDF, 2020-10-29)
• Statistical Analysis Plan (PDF, 2021-02-12)

NIH grants: 2017