EGFR ligands synergistically increase IL-17A-induced expression of psoriasis signature genes in human keratinocytes via IκBζ and Bcl3.

Various epidermal growth factor receptor (EGFR) ligands are highly expressed in the epidermis of psoriasis lesions, and abnormal EGFR activation appears to be involved in the pathogenesis of psoriasis. However, how EGFR signaling contributes to the development of psoriasis is unclear. Interleukin (IL)-17A, a critical effector of the IL-23/IL-17A pathway, increases the expression of psoriasis signature genes in keratinocytes and plays an essential role in the pathogenesis of psoriasis by inducing IκBζ, a critical transcriptional regulator in psoriasis. In this study, we stimulated primary human keratinocytes with IL-17A and various EGFR ligands to investigate whether EGFR ligands regulate the expression of psoriasis signature genes. In cultured normal human keratinocytes and a living skin equivalent, EGFR ligands did not induce psoriasis-related gene expression, but significantly enhanced the IL-17A-mediated induction of various psoriasis signature genes, including antimicrobial peptides, cytokines, and chemokines. This was dependent on an EGFR activation-mediated synergistic increase in IL-17A-induced IκBζ expression and was partially mediated by the EGFR-dependent upregulation of Bcl3. Therefore, EGFR ligands can act as synergistic agents of IL-17A signaling by stimulating the epidermal production of psoriasis signature genes in psoriasis lesions. This study reveals a potential mechanism by which EGFR signaling contributes to the pathogenesis of psoriasis.

Bcl-3 induced by IL-22 via STAT3 activation acts as a potentiator of psoriasis-related gene expression in epidermal keratinocytes.

IL-22 induces STAT3 phosphorylation and mediates psoriasis-related gene expression. However, the signaling mechanism leading from pSTAT3 to the expression of these genes remains unclear. We focused on Bcl-3, which is induced by STAT3 activation and mediates gene expression. In cultured human epidermal keratinocytes, IL-22 increased Bcl-3, which was translocated to the nucleus with p50 via STAT3 activation. The increases in CXCL8, S100As and human ß-defensin 2 mRNA expression caused by IL-22 were abolished by siRNA against Bcl-3. Although CCL20 expression was also augmented by IL-22, the knockdown of Bcl-3 increased its level. Moreover, the combination of IL-22 and IL-17A enhanced Bcl-3 production, IL-22-induced gene expression, and the expression of other psoriasis-related genes, including those encoding IL-17C, IL-19, and IL-36γ. The expression of these genes (except for CCL20) was also suppressed by the knockdown of Bcl-3. Bcl-3 overexpression induced CXCL8 and HBD2 expression but not S100As expression. We also compared Bcl-3 expression between psoriatic skin lesions and normal skin. Immunostaining revealed strong signals for Bcl-3 and p50 in the nucleus of epidermal keratinocytes from psoriatic skin. The IL-22-STAT3-Bcl-3 pathway may be important in the pathogenesis of psoriasis.

Heparinoid suppresses Der p-induced IL-1ß production by inhibiting ERK and p38 MAPK pathways in keratinocytes.

Epidermal keratinocytes initiate skin inflammation by activating immune cells. The skin barrier is disrupted in atopic dermatitis (AD) and epidermal keratinocytes can be exposed to environmental stimuli, such as house dust mite (HDM) allergens. We showed previously that HDM allergens activate the NLRP3 inflammasome of keratinocytes, thereby releasing pro-inflammatory cytokines. Heparinoid is an effective moisturizer for atopic dry skin. However, a recent report showed that heparinoid treatment can improve inflammation of lichen planus. Therefore, we hypothesized that it acts on epidermal keratinocytes not only as a moisturizer, but also as a suppressant of the triggers of skin inflammation. We found that HDM allergen-induced interleukin (IL)-1ß release from keratinocytes was inhibited significantly by heparinoid pretreatment without affecting cell viability. However, heparinoid did not affect caspase-1 release, suggesting that heparinoid did not affect HDM allergen-induced inflammasome activation. Heparinoid treatment not only decreased intracellular levels of pro-IL-1ß, but also suppressed IL-1ß messenger RNA (mRNA) expression in keratinocytes. Among the intracellular signalling pathways, the activation of extracellular signal-regulated kinase and p38 pathways, which are required for IL-1ß expression in keratinocytes, was inhibited by heparinoid treatment. The inhibitory effect of heparinoid on IL-1ß mRNA expression was also confirmed with living skin equivalents. Our results demonstrated that heparinoid suppresses the initiation of keratinocyte-mediated skin inflammation.

The microbiome of the "sterile" pustules in palmoplantar pustulosis.

The skin microbiome influences skin pathophysiology. Palmoplantar pustulosis (PPP) is a chronic skin disease characterized by infectious-like pustules on the palms and soles. These pustules are thought to be sterile because bacterial cultures obtained from the pustules are negative. However, culture methods are limited in their ability to identify all bacteria on the skin. We hypothesized that the "sterile" pustules of PPP do not lack bacteria, but rather contain a microbiome. To test this hypothesis, we identified bacteria in "sterile" pustules using non-culture methods. We conducted Sanger and 16S rRNA sequencing using primers specific to the V1-V2 region in PPP-pustulovesicles (PVs) (n = 43) and pompholyx vesicle fluids (n = 15). Sanger sequencing identified some Staphylococcus, Propionibacterium, Streptococcus and Pyrinomonas species in PPP-PVs but failed to identify any bacteria in most of the pompholyx vesicles. 16S rRNA sequencing of PPP-PVs indicated the presence of a microbiome that included various phyla, including Firmicutes, Proteobacteria, Actinobacteria and Bacteroidetes. At the genus level, smokers had higher levels of Staphylococcus in PPP-PVs compared with non-smokers. These results indicate that a microbiome exists in "sterile" pustules of PPP and that PPP smokers had higher levels of Staphylococcus in pustules. It is therefore necessary to reconsider the pathogenesis of PPP from the perspective of the microbiome.

Epidermal keratinocytes sense dsRNA via the NLRP3 inflammasome, mediating interleukin (IL)-1ß and IL-18 release.

Skin epidermis, in addition to its barrier function, is able to actively sense harmful pathogens using pattern recognition receptors. In immune cells, the nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain containing 3 (NLRP3) inflammasome can mediate innate immunity against viral infection via a mechanism involving viral dsRNA recognition. Epidermal keratinocytes express NLRP3 inflammasome, which can sense contact sensitizers and mite allergens, leading to pro-interleukin (IL)-1ß and pro-IL-18 cleavage into their active forms. Skin often faces viral infection. However, it is unknown whether viral dsRNA can be detected by the keratinocyte NLRP3 inflammasome. We transfected polyinosinic:polycytidylic acid (poly I:C), a synthetic viral dsRNA analogue, into cultured primary human keratinocytes at the aid of Lipofectamine 2000, and found that transfected poly I:C activated caspase-1 and induced caspase-1-dependent release of IL-1ß and IL-18, which were suppressed on transfection with NLRP3 siRNA. The activation of keratinocyte NLRP3 inflammasome by transfected poly I:C was dependent on dsRNA-induced protein kinase (PKR) activation, and priming with type I interferons upregulated NLRP3 inflammasome activation through promoting PKR activation in poly I:C-transfected keratinocytes. In conclusion, the NLRP3 inflammasome can act as a sensor of dsRNA in epidermal keratinocytes, which may be important in both skin innate immune defense against viral infection and skin inflammation.

Cefcapene Pivoxil Hydrochloride Is a Potentially New Treatment for Palmoplantar Pustulosis with Pustulotic Arthro-Osteitis.

Pustulosis palmaris et plantaris or palmoplantar pustulosis (PPP) is a refractory pustular eruption of the palms and soles with unknown etiology. In addition to skin lesions, PPP patients may present with severe joint pain and pustulotic arthro-osteitis (PAO), especially of the sternoclavicular joint. PAO is sometimes regarded as a variant of synovitis, acne, pustulosis, hyperostosis and osteitis (SAPHO) syndrome. Hence, macrolide and tetracycline antibiotics are used for the treatment of PPP with PAO. We report 3 cases of PPP with PAO that did not improve upon administration of macrolide antibiotics with NSAIDs. After administration of cefcapene pivoxil hydrochloride (CFPN-PI), a third-generation cephalosporin, the swelling and sternoclavicular joint pain were promptly reduced and dramatically improved in all 3 cases. We review the conventional antibiotic treatments used currently and propose CFPN-PI as a potentially new therapy for PPP or PPP + PAO.

Inflammatory peeling skin syndrome caused by homozygous genomic deletion in the PSORS1 region encompassing the CDSN gene.

Peeling skin syndrome (PSS) type B is a rare recessive genodermatosis characterized by lifelong widespread, reddish peeling of the skin with pruritus. The disease is caused by small-scale mutations in the Corneodesmosin gene (CDSN) leading to premature termination codons. We report for the first time a Japanese case resulting from complete deletion of CDSN. Corneodesmosin was undetectable in the epidermis, and CDSN was unamplifiable by PCR. QMPSF analysis demonstrated deletion of CDSN exons inherited from each parent. Deletion mapping using microsatellite haplotyping, CGH array and PCR analysis established that the genomic deletion spanned 49-72 kb between HCG22 and TCF19, removing CDSN as well as five other genes within the psoriasis susceptibility region 1 (PSORS1) on 6p21.33. This observation widens the spectrum of molecular defects underlying PSS type B and shows that loss of these five genes from the PSORS1 region does not result in an additional cutaneous phenotype.

Increased serine protease activity and cathelicidin promotes skin inflammation in rosacea.

Acne rosacea is an inflammatory skin disease that affects 3% of the US population over 30 years of age and is characterized by erythema, papulopustules and telangiectasia. The etiology of this disorder is unknown, although symptoms are exacerbated by factors that trigger innate immune responses, such as the release of cathelicidin antimicrobial peptides. Here we show that individuals with rosacea express abnormally high levels of cathelicidin in their facial skin and that the proteolytically processed forms of cathelicidin peptides found in rosacea are different from those present in normal individuals. These cathelicidin peptides are a result of a post-translational processing abnormality associated with an increase in stratum corneum tryptic enzyme (SCTE) in the epidermis. In mice, injection of the cathelicidin peptides found in rosacea, addition of SCTE, and increasing protease activity by targeted deletion of the serine protease inhibitor gene Spink5 each increases inflammation in mouse skin. The role of cathelicidin in enabling SCTE-mediated inflammation is verified in mice with a targeted deletion of Camp, the gene encoding cathelicidin. These findings confirm the role of cathelicidin in skin inflammatory responses and suggest an explanation for the pathogenesis of rosacea by demonstrating that an exacerbated innate immune response can reproduce elements of this disease.

A Successful Switch From Ustekinumab to an Extended Dosing Interval of Guselkumab Without Induction in a Patient With Psoriasis Vulgaris.

Psoriasis vulgaris, also known as plaque-type psoriasis, is the most common form of psoriasis. It is characterized by erythematous plaques covered with scales. Among the available treatments, the fully human monoclonal antibodies ustekinumab (UST) and guselkumab (GUS) have low immunogenicity. Additionally, GUS has not been found to have a significant risk of inducing the development of clinically relevant neutralizing antibodies. Therefore, we sometimes consider switching to GUS when UST is insufficiently effective. However, switching to another biological agent usually requires an induction phase, potentially incurring additional costs. We herein present the first case of a successful transition from UST 90 mg to an extended dosing interval of GUS without an induction phase. This approach may be a viable and cost-saving option, especially for patients with relatively low disease activity.

Paradoxical Eczema Associated With Interleukin-17A Inhibitor Use in a Patient With Generalized Pustular Psoriasis Accompanied by Asthma.

Although rare, paradoxical eczema (PE) is an adverse event associated with the use of biological agents to treat psoriasis, particularly in patients with atopic predispositions. We report the first case of severe PE induced by secukinumab in a patient with generalized pustular psoriasis (GPP) and asthma. A woman in her 50s with a history of interstitial nephritis attributable to Sjogren's syndrome experienced a flare-up of GPP after discontinuing mycophenolate mofetil and was hospitalized. Treatment with secukinumab accompanied by an increased prednisolone level afforded rapid improvement, but she subsequently developed widespread, itchy, serous papules and erythema. A biopsy confirmed that the erythema was an eczematous reaction, thus PE. Her condition improved after switching from secukinumab to deucravacitinib with a temporary increase in the prednisolone level; no recurrence of GPP or PE was observed for 11 months. Elevated serum levels of interleukin (IL)-17A, IL-22, and the Th2 chemokine TARC recorded at the onset time of PE suggested that these mediators contributed to the observed pathology. Our case highlights the need for careful consideration when prescribing IL-17 inhibitors to patients with GPP, particularly those with atopic predispositions, given the potential activation of the Th2 axis and thus severe eczematous reactions. Further research is required to understand the essential nature of PE in patients with GPP and the roles of IL-17A and IL-22 in this context.

Efficacy and Safety of Brodalumab, an Anti-interleukin-17 Receptor A Monoclonal Antibody, for Palmoplantar Pustulosis: 16-Week Results of a Randomized Clinical Trial.

BACKGROUND: Palmoplantar pustulosis (PPP), a refractory skin disease characterized by repeated eruptions of sterile pustules and vesicles on palms and/or soles, involves interleukin-17 pathway activation. Brodalumab, a fully human anti-interleukin-17 receptor A monoclonal antibody, is being investigated for use in PPP treatment. OBJECTIVE: The aim was to assess the efficacy and safety of brodalumab in Japanese PPP patients with moderate or severe pustules/vesicles. METHODS: A phase 3, randomized, double-blind, placebo-controlled trial was conducted between July 2019 and August 2022, at 41 centers in Japan. Patients aged 18-70 years with a diagnosis of PPP for ≥ 24 weeks, a PPP Area Severity Index (PPPASI) score of ≥ 12, a PPPASI subscore of pustules/vesicles of ≥ 2, and inadequate response to therapy were included. Participants were randomized 1:1 to receive brodalumab 210 mg or placebo, subcutaneously (SC) at baseline, weeks 1 and 2, and every 2 weeks (Q2W) thereafter until week 16. Changes from baseline to week 16 in the PPPASI total score (primary endpoint) and other secondary skin-related endpoints and safety endpoints were assessed. RESULTS: Of the 126 randomized patients, 50 of 63 in the brodalumab group and 62 of 63 in the placebo group completed the 16-week period. Reasons for discontinuation were adverse event (n = 6), withdrawal by patient/parent/guardian (n = 3), progressive disease (n = 3), and lost to follow-up (n = 1) in the brodalumab group and Good Clinical Practice deviation (n = 1) in the placebo group. Change from baseline in the PPPASI total score at week 16 was significantly higher (p = 0.0049) with brodalumab (least-squares mean [95% confidence interval {CI}] 13.73 [10.91-16.56]) versus placebo (8.45 [5.76-11.13]; difference [95% CI] 5.29 [1.64-8.94]). At week 16, brodalumab showed a trend of rapid improvement versus placebo for PPPASI-50/75/90 response (≥ 50%/75%/90% improvement from baseline) and Physician's Global Assessment 0/1 score: 54% versus 24.2%, 36.0% versus 8.1%, 16.0% versus 0.0%, and 32.0% versus 9.7%, respectively. Infection was the dominant treatment-emergent adverse event (TEAE); the commonly reported TEAEs were otitis externa (25.4%/1.6%), folliculitis (15.9%/3.2%), nasopharyngitis (14.3%/4.8%), and eczema (14.3%/12.9%) in the brodalumab/placebo groups, respectively. The severity of most TEAEs reported was Grade 1 or 2 and less frequently Grade ≥ 3. CONCLUSIONS: Brodalumab SC 210 mg Q2W demonstrated efficacy in Japanese PPP patients. The most common TEAEs were mild infectious events. TRIAL REGISTRATION: NCT04061252 (Date of Trial Registration: August 19, 2019).

Effects of hot bath therapy on cholinergic urticaria with hypohidrosis or anhidrosis.

Cholinergic urticaria with hypohidrosis or anhidrosis (CUHA) can impair quality of life due to itching, tingling, and reduced sweating. Current treatment options for CUHA include antihistamines, pulsed steroids, and sweat-promoting therapies such as exercise or hot baths. However, the efficacy of these therapies, particularly hot bath therapy, has yet to be established. We evaluated the efficacy of hot bath therapy in patients with CUHA. We enrolled eight patients who underwent hot bath therapy between January 2010 and August 2022. Patients had a half-body bath in a bathtub filled with hot water (40-43°C) for 30-60 minutes daily for 3-7 days. After treatment, pain improved in three (42.9%) patients, urticaria improved in four (50%) patients, and anhidrosis improved in five (62.5%) patients without any severe adverse events. Because hot bath therapy is easily performed, it should be considered a treatment option for patients with CUHA.

Trehalose prevents IL-4/IL-13-induced skin barrier impairment by suppressing IL-33 expression and increasing Nrf2 activation in human keratinocytes in vitro.

Skin barrier dysfunction initiates or deteriorates various cutaneous problems, such as atopic dermatitis (AD). At high concentrations, the nonreducing disaccharide α-d-glucopyranosyl α-d-glucopyranoside (trehalose) induces a transient senescence-like state in fibroblasts and promotes wound repair. Here, we investigated the effect of trehalose on normal human keratinocytes (KCs) and demonstrated its specific role in the skin barrier. RNA-seq analysis revealed that trehalose regulates the expression of many skin-barrier-associated genes. T helper 2 (Th2) cytokines interleukin (IL)-4/IL-13 were observed to downregulate several differentiation markers (FLG, LOR, K1, and K10) and epidermal antimicrobial proteins in monolayer-cultured KCs and living skin equivalents (LSE), and impaired skin barrier function in LSE, all of which were significantly upregulated or restored by trehalose. Trehalose inhibited IL-33 expression and reduced nuclear IL-33 levels by activating MEK5-extracellular signal-regulated kinase 5 (ERK5) and suppressing MEK1/2-ERK pathway. It also increased nuclear factor erythroid 2-related factor 2 (Nrf2) activation to trigger antioxidant enzyme production via c-Jun N-terminal kinase (JNK), thus, neutralizing IL-4/IL-13-mediated oxidative stress. Trehalose prevented IL-4/IL-13-mediated signal transducer and activator of transcription (STAT)3/STAT6 activation and restored IL-4/IL-13-suppressed skin barrier molecules via IL-33 downregulation and Nrf2 activation. This study demonstrated that trehalose may play a role in skin barrier repair in AD.

Exploratory Efficacy Evaluation of Apremilast for the Treatment of Japanese Patients with Palmoplantar Pustulosis: 32-Week Results from a Phase 2, Randomized, Placebo-Controlled Study.

INTRODUCTION: Palmoplantar pustulosis (PPP) is a pruritic, painful, chronic dermatitis that greatly impacts functioning and quality of life and can be difficult to treat. Approved treatment options for PPP are limited, and many patients do not fully respond to current treatments. METHODS: This was a randomized, double-blind, placebo-controlled, phase 2 study in Japanese patients with moderate to severe PPP and inadequate response to topical treatment. Patients were randomized 1:1 to receive apremilast 30 mg twice daily or placebo for 16 weeks followed by an extension phase where all patients received apremilast through week 32. PPP Area and Severity Index (PPPASI), modified PPPASI (which evaluates pustules and vesicles separately), and Palmoplantar Severity Index (PPSI) total scores and subscores (erythema, pustules/vesicles, and desquamation/scales) were evaluated over 32 weeks of apremilast treatment. Achievement of ≥ 50% improvement in PPPASI (PPPASI-50) was evaluated at week 16 among baseline demographic and clinical characteristic subgroups. RESULTS: At week 16, improvements in total score and subscores for PPPASI, modified PPASI, and PPSI, as well as rates of PPPASI-50 were at least moderately greater with apremilast than placebo. Mean PPPASI total score decreased by - 68.3% from baseline to week 32 with continued apremilast treatment. At week 32, mean change from baseline in PPPASI/modified PPPASI subscores ranged from - 58.5% to - 77.0% with apremilast. At week 32, PPSI total score for physician and patient assessments decreased by - 51.3% and - 40.0%, respectively, with continued apremilast treatment. PPPASI-50 response at week 16 was greater with apremilast versus placebo in most demographic and baseline characteristic subgroups. CONCLUSIONS: Improvements in all PPPASI and PPSI total scores and subscores observed with apremilast over 16 weeks were maintained through 32 weeks in patients with moderate to severe PPP and inadequate response to topical treatment. Rates of PPPASI-50 response at week 16 were mostly consistent across patient subgroups. CLINICALTRIALS: GOV: NCT04057937.

A fluorescence imaging technique suggests that sweat leakage in the epidermis contributes to the pathomechanism of palmoplantar pustulosis.

Sweat is an essential protection system for the body, but its failure can result in pathologic conditions, including several skin diseases, such as palmoplantar pustulosis (PPP). As reduced intraepidermal E-cadherin expression in skin lesions was confirmed in PPP skin lesions, a role for interleukin (IL)-1-rich sweat in PPP has been proposed, and IL-1 has been implicated in the altered E-cadherin expression observed in both cultured keratinocytes and mice epidermis. For further investigation, live imaging of sweat perspiration on a mouse toe-pad under two-photon excitation microscopy was performed using a novel fluorescent dye cocktail (which we named JSAC). Finally, intraepidermal vesicle formation which is the main cause of PPP pathogenesis was successfully induced using our "LASER-snipe" technique with JSAC. "LASER-snipe" is a type of laser ablation technique that uses two-photon absorption of fluorescent material to destroy a few acrosyringium cells at a pinpoint location in three-dimensional space of living tissue to cause eccrine sweat leakage. These observatory techniques and this mouse model may be useful not only in live imaging for physiological phenomena in vivo such as PPP pathomechanism investigation, but also for the field of functional physiological morphology.

What is the role of antimicrobial peptides (AMP) in acne vulgaris?

Acne vulgaris is the most common disorder of the pilosebaceous unit leading to inflamed skin characterized by the formation of comedones, papules, pustules and scarring. There is increasing evidence that the abundance of Propionibacterium acnes (P. acnes) in the inflamed acne lesions triggers inflammation. Therefore, in addition to treatment with retinoids, the use of antimicrobial agents has been established as a treatment option for acne. This indicates that antimicrobial mechanisms to control the growth of P. acnes may have an important influence on the severity of inflammatory acne. One import antimicrobial innate defense system comprises the production of antimicrobial peptides (AMP), small molecules with a broad spectrum of antimicrobial activity as well as immunomodulatory properties. Although the role of AMP in acne is still emerging, there is increasing evidence that AMP may be of importance in acne. The aim of this viewpoint is to provide some hypotheses about the potential function of AMP in the pathogenesis of acne and to discuss potential AMP-based therapies for the treatment of acne.

Nuclear IL-33 Plays an Important Role in EGFR-Mediated Keratinocyte Migration by Regulating the Activation of Signal Transducer and Activator of Transcription 3 and NF-κB.

Nuclear IL-33 levels are high at the epidermal edges of skin wounds and facilitate wound healing. However, IL-33-mediated regulation of keratinocyte (KC) biology during wound healing remains poorly understood. During skin-wound healing, KC migration and re-epithelialization are mediated predominantly by EGFR signaling activation and depend on the function of signal transducer and activator of transcription 3 (STAT3). We found that migrating KCs at the leading edges of mouse skin wounds exhibited concomitant induction and nuclear colocalization of IL-33 and phosphorylated STAT3. In cultured human KCs, activation of EGFR signaling caused rapid elevation of nuclear IL-33, which directly interacts with phosphorylated STAT3, promoting STAT3 activation. In vitro KC migration and wound-healing assays revealed that high nuclear IL-33 levels were required for KC migration and wound closure. KC mobility associated with a lack of suprabasal epidermal keratins and extracellular matrix degradation mediated by matrix metalloproteinases (MMPs) control cell migration at the intracellular and extracellular levels, respectively. In EGFR-activated KCs, nuclear IL-33 mediated keratin 1 and 10 downregulation and MMP9 upregulation by promoting STAT3 activation and limited MMP1, MMP3, and MMP10 induction by suppressing NF-κB transactivation. Thus, epidermal nuclear IL-33 is involved in KC migration and wound closure by regulating the STAT3 and NF-κB pathways.

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).

A clinical trial of spesolimab for patients with palmoplantar pustulosis. Palmoplantar pustulosis (PPP) is a painful, difficult-to-treat skin disease that is found on patients' palms and the soles of their feet. In this clinical trial, we studied an injected medicine called spesolimab for treating patients with PPP. Patients were split into five groups; four groups received different doses of spesolimab and one received placebo (an injection without spesolimab). After 16 weeks, patients receiving placebo switched to spesolimab. We measured the body area affected by PPP and how severe PPP was at week 16. Patients' doctors also assessed skin affected by PPP. At 16 weeks of treatment, there was no significant difference between spesolimab and placebo in terms of the PPP-affected area and severity. However, more patients had clear or almost clear skin with spesolimab than placebo. Among non-Asian patients, more showed an improvement in their PPP with spesolimab than with placebo; this was not the case with Asian patients. Patients taking spesolimab or placebo reported side effects, of which the most common were colds, aches and headaches. More patients receiving spesolimab reported a reaction at the injection site compared with placebo. We monitored patients for up to 1 year, and results remained similar. We showed that spesolimab may have a modest effect on the body area affected by PPP, as well as the severity of PPP, and did not seem to cause more side effects than placebo, except for reactions at the injection site.