A multicentre open-label study of apremilast in palmoplantar pustulosis (APLANTUS)

A systematic review of recent randomized controlled trials for palmoplantar pustulosis

Background: Palmoplantar pustulosis (PPP) is a chronic inflammatory condition, that leads to significant functional impairment and reduced quality of life. Despite its low incidence, treatment options are diverse and often ineffective, necessitating a review of recent therapeutic advances.

Objective: This review aims to evaluate the efficacy and safety of recent therapeutic options for the treatment of PPP, focusing on phototherapy, systemic therapies, and biologics.

Materials and methods: A systematic literature search identified 13 studies evaluating phototherapy and systemic therapies, including biologics. Inclusion criteria focused on randomized controlled trials with participants diagnosed with PPP.

Results: Phototherapy showed success: excimer laser demonstrated high efficacy for severe disease [PPP Area and Severity Index (PPPASI)-75 of 95.0%], while psoralen plus ultraviolet A therapy with retinoids or fumaric acid esters worked well in milder disease (PPPASI-90 of 90.0 and 81.8%, respectively). Evidence supports the efficacy and safety of guselkumab, brodalumab, and apremilast over a range of disease severity (PPPASI-50 ranged from 57.4 to 78.3% at week 16). Agents including anakinra, secukinumab, spesolimab, and RIST4721 (primary outcomes not achieved) may not be first-line treatments. By targeting multiple inflammatory pathways in PPP, JAK inhibitors may be more effective than biologics in treating PPP; however, more research is needed to confirm their safety and appropriate use.

Conclusions: Multiple new treatments exist for PPP with promising results, however longer-term studies with standardized outcome reporting are needed to determine optimal treatment strategies and their comparative efficacy.

Apremilast is a potentially useful treatment for severe palmoplantar pustulosis with extra-palmoplantar symptoms

Palmoplantar pustulosis (PPP) is a chronic inflammatory skin disorder affecting the palms and soles. In rare cases, severe patients develop acute extra-palmoplantar lesions often accompanied by arthralgia. Such cases with extensive symptoms often necessitate systemic treatments with variable efficacy and potential side effects. Apremilast, known for its broad immune response modulation, presents promise as a therapeutic option for severe PPP with joint and extra-palmoplantar lesions. This case highlights apremilast as a potential systemic treatment for such cases with minimal side effects.

Treatment Patterns and Negative Health Outcomes in Palmoplantar Pustulosis Patients in Germany and the US

INTRODUCTION

Limited information exists on the epidemiology, treatment, and burden of palmoplantar pustulosis (PPP) and defining the optimal course of treatment remains challenging without approved targeted treatments in most countries. Here, we describe the clinical and demographic characteristics, treatments received, and negative health outcomes experienced among patients with PPP in the United States (US) and Germany.

METHODS

Retrospective cohort study between 2016 and 2021 using data from the US Merative™ MarketScan® Research Database and IQVIA™ German Disease Analyzer. Adult patients with PPP (ICD-10-CM L40.3) were followed from the date of their first qualifying PPP diagnosis and continued until the earlier of disenrollment or end date of database, during which treatment patterns and incidence rates of negative health outcomes were assessed. Treatment patterns included adherence, non-persistence, discontinuation, re-initiation, switching, and combination therapy.

RESULTS

The prevalence of PPP was 0.005% and 0.065% in the MarketScan database and German Disease Analyzer, respectively, with 1629 and 3866 patients meeting the inclusion criteria. Most patients were female (71.3%, 67.8%), with mean (SD) age of 54.1 (11.7) and 56.9 (14.3) years, respectively. One year post index, most patients received topical treatment (77.4%, 65.3%), but non-persistence and discontinuation were high. Oral and biologic treatments displayed higher levels of adherence, particularly apremilast and tofacitinib among oral treatments and TNF inhibitors and IL-23 inhibitors among biologics. Rates of negative health outcomes were higher among patients not receiving treatment post-index compared with those receiving treatment post-index across both databases, regardless of prior treatment history.

CONCLUSIONS

Establishing treatment guidelines remains an unmet need for patients with PPP and could improve quality of life by reducing the occurrence of negative health outcomes. The findings from this study may provide insight into the effectiveness of current treatment options for patients with PPP and can be leveraged to support the development of treatment guidelines.

Spesolimab Efficacy and Safety in Patients with Moderate-to-Severe Palmoplantar Pustulosis: A Multicentre, Double-Blind, Randomised, Placebo-Controlled, Phase IIb, Dose-Finding Study

INTRODUCTION

We evaluated the anti-interleukin-36 receptor antibody spesolimab in patients with moderate-to-severe palmoplantar pustulosis (PPP).

METHODS

This phase IIb trial comprised a loading dose period to week (W) 4, then maintenance dosing to W52. Patients were randomised 2:1:1:1:2 to subcutaneous spesolimab 3000 mg to W4 then 600 mg every 4 weeks (q4w), spesolimab 3000 mg to W4 then 300 mg q4w, spesolimab 1500 mg to W4 then 600 mg q4w, spesolimab 1500 mg to W4, 300 mg q4w to W16 then 300 mg every 8 weeks (q8w), or placebo switching to spesolimab 600 mg q4w at W16. The primary efficacy endpoint was percentage change from baseline in Palmoplantar Pustular Area and Severity Index (PPP ASI) at W16. Secondary endpoints included a Palmoplantar Pustular Physician's Global Assessment (PPP PGA) score of 0/1. Safety (including adverse events [AEs], local tolerability) was assessed.

RESULTS

152 patients were treated. The primary endpoint was not met; mean differences for spesolimab versus placebo ranged from - 14.6% (95% confidence interval [CI]: - 31.5%, 2.2%) to - 5.3% (95% CI: - 19.1%, 8.6%); none reached significance. At W16, 23 (21.1%) and two (4.7%) patients in the combined spesolimab and placebo groups, respectively, achieved PPP PGA 0/1 (mean difference 16.4%; 95% CI: 3.8%, 25.7%), increasing to 59 (54.1%; combined spesolimab) and 12 (27.9%; placebo switch to spesolimab) patients at W52. Non-Asian patients had significant improvements in the primary endpoint (mean difference - 17.7%; nominal P = 0.0394) and PPP PGA 0/1 at W16 with spesolimab versus placebo. Rates of AEs and AE-related discontinuations were similar for spesolimab and placebo. Local tolerability events and injection-site reactions were more frequent with spesolimab than placebo.

CONCLUSION

The primary objective to demonstrate a non-flat dose-response relationship and proof-of-concept was not achieved; improvements with spesolimab occurred in secondary endpoints and in non-Asian patients, indicating potential modest benefits. Spesolimab was generally well tolerated (ClinicalTrials.gov NCT04015518).

Palmoplantar Pustulosis: A Systematic Review of Risk Factors and Therapies

Palmoplantar pustulosis (PPP) is a chronic, relapsing, inflammatory disease that can occur alone or in association with arthritis. There is still controversy about whether it should be separated from psoriasis or classified as pustular psoriasis. Furthermore, drug-induced paradoxical PPP is a special variant of PPP that differs from classic PPP in several ways. Treatment of PPP is still challenging, and there are a number of treatment-resistant cases. This review summarizes the risk factors for the development of PPP and the currently available treatment modalities. Female sex, smokers or ex-smokers, obesity, thyroid dysfunction, and treatment with a tumor necrosis factor (TNF)-α inhibitor have been identified as risk factors for the disease's development, severity, and course. Topical treatments and phototherapy are effective for some patients and are used as a first-line or adjuvant treatment modality. Conventional treatments including retinoids and fumaric acid show good effects and can increase the efficacy of treatment with psoralen + ultraviolet light therapy (PUVA). Ciclosporin is fast acting, but relapse mostly occurs immediately after cessation. TNF-α inhibitors are efficient, and an even better response can be achieved with IL-17 and IL-23 blockers as well as apremilast. The effect of Janus kinase inhibitors seems to be promising according to case reports, but further investigations with larger cohorts are needed.

Efficacy and Safety of Apremilast for the Treatment of Japanese Patients with Palmoplantar Pustulosis: Results from a Phase 2, Randomized, Placebo-Controlled Study

BACKGROUND

Palmoplantar pustulosis (PPP) is a pruritic, painful, recurrent, and chronic dermatitis with limited therapeutic options.

OBJECTIVE

To evaluate the efficacy and safety of apremilast for the treatment of Japanese patients with PPP and inadequate response to topical treatment.

METHODS

This phase 2, randomized, double-blind, placebo-controlled study enrolled patients with Palmoplantar Pustulosis Area and Severity Index (PPPASI) total score ≥ 12 and moderate or severe pustules/vesicles on the palm or sole (PPPASI pustule/vesicle severity score ≥ 2) at screening and baseline with an inadequate response to topical treatment. Patients were randomized (1:1) to apremilast 30 mg twice daily or placebo for 16 weeks, followed by a 16-week extension phase during which all patients received apremilast. The primary endpoint was achievement of PPPASI-50 response (≥ 50% improvement from baseline in PPPASI). Key secondary endpoints included change from baseline in PPPASI total score, Palmoplantar Pustulosis Severity Index (PPSI), and patient's visual analog scale (VAS) for PPP symptoms (pruritus and discomfort/pain).

RESULTS

A total of 90 patients were randomized (apremilast: 46; placebo: 44). A significantly greater proportion of patients achieved PPPASI-50 at week 16 with apremilast versus placebo (P = 0.0003). Patients receiving apremilast showed greater improvement in PPPASI at week 16 versus placebo (nominal P = 0.0013), as well as PPSI and patient-reported pruritus and discomfort/pain (nominal P ≤ 0.001 for all). Improvements were sustained through week 32 with apremilast treatment. The most common treatment-emergent adverse events included diarrhea, abdominal discomfort, headache, and nausea.

CONCLUSIONS

Apremilast treatment demonstrated greater improvements in disease severity and patient-reported symptoms versus placebo at week 16 in Japanese patients with PPP with sustained improvements through week 32. No new safety signals were observed.

CLINICALTRIALS

GOV: NCT04057937.

An update on therapeutic options for palmoplantar pustulosis: a narrative review and expert recommendations

INTRODUCTION

Palmoplantar pustulosis (PPP) is a chronic inflammatory skin disease belonging to the localized form of pustular psoriasis. It is characterized by sterile pustule formation in palms and soles and a recurrent disease course. Although we have many treatments for PPP, there is no authoritative guidance.

AREAS COVERED

A thorough search of PubMed was conducted to identify studies in PPP from 1973 onwards, with additional references to specific articles. Any treatment methods were outcomes of interest, including topical treatment, systemic treatment, biologics, other targeted treatments, phototherapy, and tonsillectomy.

EXPERT OPINION

Topical corticosteroids are suggested as first-line therapy. Oral acitretin has become the most applied systemic retinoid recommended in PPP without joint involvement. For patients with arthritis, immunosuppressants like cyclosporin A and methotrexate are more recommended. UVA1, NB-UVB, and 308-nm excimer laser are effective phototherapy options. The combinations of topical or systemic agents and phototherapy may enhance the efficacy, particularly in recalcitrant cases. Secukinumab, ustekinumab, and apremilast are the most investigated targeted therapies. However, heterogeneous reported outcomes in clinical trials provided low-to-moderate quality evidence of their efficacy. Future studies are required to address these evidence gaps. We suggest managing PPP based on the acute phase, maintenance phase, and comorbidities.

Interleukin-19 Levels Are Increased in Palmoplantar Pustulosis and Reduced following Apremilast Treatment

Palmoplantar pustulosis (PPP) is a chronic inflammatory skin disease characterised by neutrophilic granulocyte (neutrophil)-filled pustules on the palms and soles. The pathogenesis of PPP is poorly understood. This study conducted an identification of the immune mediators associated with PPP and an exploration of apremilast treatment effects on them. We screened for immune mediators elevated in blood taken from 68 patients with PPP versus control participants and included the most promising parameters in the protocol of phase the 2, multicentre study of apremilast (PDE4 inhibitor) in 21 patients with moderate-to-severe PPP (APLANTUS; EudraCT 2016-005122-11) for respective analysis of blood and skin samples of study patients. We investigated stimulated neutrophils and three-dimensional reconstituted epidermis cultures. Interleukin (IL)-19 was found to be the most upregulated immune mediator in the blood of PPP patients. IL-19 serum levels were independent of patients' age, gender, and BMI but were associated with strongly upregulated cutaneous IL-19 expression and correlated with the number of palmoplantar pustules. In patients participating in the APLANTUS study, apremilast reduced pustules more effectively than erythema and scaling. Moreover, this treatment significantly reduced IL-19 blood and skin levels. The reduction in IL-19 blood levels at week 4 correlated with the reduction in pustule counts at week 20 (end of treatment). IL-19 was expressed by neutrophils activated in vitro and induced CXCL6, a neutrophil-attracting chemokine, in epidermis models. This work demonstrates elevated IL-19 levels in the blood and skin of PPP patients and suggests a relevant role of this cytokine in the appearance of pustules in this disorder. It also suggests the suitability of IL-19 blood levels as a predictive biomarker for the treatment response of PPP patients, which should be validated in further studies.

Comparison of the Inflammatory Circuits in Psoriasis Vulgaris, Non‒Pustular Palmoplantar Psoriasis, and Palmoplantar Pustular Psoriasis

Palmoplantar pustular psoriasis (PPPP) and non‒pustular palmoplantar psoriasis (NPPP) are localized, debilitating forms of psoriasis. The inflammatory circuits involved in PPPP and NPPP are not well-understood. To compare the cellular and immunological features that differentiate PPPP and NPPP, skin biopsies were collected from a total of 30 participants with PPPP, NPPP, and psoriasis vulgaris (PV) and from 10 healthy participants. A subset consented to a second biopsy after 3 additional weeks off medication. Histologic staining of lesional and nonlesional skin showed higher neutrophil counts in PPPP than in NPPP and PV and higher CD8⁺ T-cell counts in NPPP. RNA sequencing and transcriptional analysis of skin biopsies showed enhanced IFN-γ pathway activation in NPPP lesions but stronger signatures of IL-17 pathway and neutrophil-related genes (e.g., IL36A) in PPPP lesional skin. Serum analysis on the Olink platform detected higher concentrations of T helper type 1, IFN-γ‒inducible chemokines in NPPP, and higher neutrophil-associated cytokines in PPPP. Taken together, this evidence suggests more pronounced T helper 1‒mediated inflammation in NPPP than in PV and PPPP and stronger neutrophil-associated activity in PPPP than in NPPP and PV. These data support targeting inflammatory pathways associated with neutrophilic inflammation (e.g., IL-36 signaling) for therapeutic development in PPPP.

Involvement of Molecular Mechanisms between T/B Cells and IL-23: From Palmoplantar Pustulosis to Autoimmune Diseases

Palmoplantar pustulosis (PPP) is a disease that causes recurrent blisters and aseptic pustules on the palms and soles. It has been suggested that both innate and acquired immunity are involved. In particular, based on the tonsils and basic experiments, it has been assumed that T and B cells are involved in its pathogenesis. In addition, the results of clinical trials have suggested that IL-23 is closely related to the pathogenesis. This review describes PPP and the genetic background, the factors involved in the onset and exacerbation of disease and its relation to the molecular mechanism. In addition, we describe the usefulness of biological therapy and its implications in relation to the importance in pathology, the pathogenesis of PPP, the importance of the role of the IL-23-Th17 axis and IL-36 in PPP. Furthermore, we describe an animal experimental model of PPP, the efficacy and mechanism of action of guselkumab, an anti-IL-23 antibody, the latest research, and finally the possibility for it to be effective for other autoimmune diseases.

Pustular Psoriasis: From Pathophysiology to Treatment

Pustular psoriasis (PP) is a clinicopathological entity encompassing different variants, i.e., acute generalized PP (GPP), PP of pregnancy (impetigo herpetiformis), annular (and circinate) PP, infantile/juvenile PP, palmoplantar PP/palmoplantar pustulosis, and acrodermatitis continua of Hallopeau (ACH), which have in common an eruption of superficial sterile pustules on an erythematous base. Unlike psoriasis vulgaris, in which a key role is played by the adaptive immune system and interleukin (IL)-17/IL-23 axis, PP seems to be characterized by an intense inflammatory response resulting from innate immunity hyperactivation, with prominent involvement of the IL-36 axis. Some nosological aspects of PP are still controversial and debated. Moreover, owing to the rarity and heterogeneity of PP forms, data on prognosis and therapeutic management are limited. Recent progresses in the identification of genetic mutations and immunological mechanisms have promoted a better understanding of PP pathogenesis and might have important consequences on diagnostic refinement and treatment. In this narrative review, current findings in the pathogenesis, classification, clinical features, and therapeutic management of PP are briefly discussed.

Pustular Psoriasis and Acute Generalized Exanthematous Pustulosis

The similarity between pustular psoriasis (PP) and acute generalized exanthematous pustulosis (AGEP) poses problems in the diagnosis and treatment of these two conditions. Significant clinical and histopathologic overlap exists between PP and AGEP. PP is an inflammatory disorder that has numerous clinical subtypes, but all with sterile pustules composed of neutrophils. AGEP is a severe cutaneous adverse reaction that is also characterized by non-follicular sterile pustules. Clinical features that suggest a diagnosis of PP over AGEP include a history of psoriasis and the presence of scaling plaques. Histologically, eosinophilic spongiosis, vacuolar interface dermatitis, and dermal eosinophilia favor a diagnosis of AGEP over PP. Importantly, PP and AGEP vary in clinical course and treatment. PP treatment involves topical steroids, oral retinoids, and systemic immunosuppressants. Newer therapies targeting IL-36, IL-23, IL-1, and PDE-4 have been investigated. The removal of the offending agent is a crucial part of the treatment of AGEP.