Response to adalimumab in Caucasian and Asian patients with hidradenitis suppurativa: A retrospective cohort study of an Australian cohort stratified by patient-reported ethnicity.

BACKGROUND/OBJECTIVES: Caucasian and Asian patients with hidradenitis suppurativa demonstrate significant differences with regard to age, gender and body mass index. Demographic characteristics are known to influence the efficacy and drug survival of hidradenitis suppurativa therapeutics including biologic therapies. What remains unknown is the impact of ethnicity upon the efficacy of therapeutics once demographic and disease characteristics have been taken into account. This is an important question given the expansion of biologic therapies for HS into the global patient community. METHODS: We assessed 170 patients from a single HS specialist centre in Australia stratified by patient-identified ethnicity including those identifying as either Caucasian or Asian. RESULTS: Asian patients demonstrated lower BMI, higher rates of smoking and greater odds of Hurley stage 3 disease with tunnels than Caucasian patients in line with the reported literature. There was no significant difference between percentage of individuals achieving HiSCR50 or IHS4-55 at Week 16. Significant differences were seen in median time to secondary loss of response, and Kaplan-Meier curve analysis showed a significant difference between curves when stratified by patient-reported ethnicity. Cox regression analysis demonstrated after accounting for age, gender, BMI, smoking and Hurley stage, the significance of ethnicity in influencing time to secondary loss of response disappears. CONCLUSIONS: Caucasian or Asian ethnicity does not influence response to adalimumab treatment on patients with hidradenitis suppurativa.

Standardized Protocols for Clinical and Histopathological Characterization of Hidradenitis Suppurativa Tissue Specimens.

Methods for describing and reporting the clinical and histologic characteristics of cutaneous tissue samples from patients with hidradenitis suppurativa (HS) are not currently standardized, limiting clinicians' and scientists' ability to uniformly record, report, and communicate about the characteristics of tissue used in translational experiments. A recently published consensus statement outlined morphological definitions of typical HS lesions, but no consensus has been reached regarding clinical characterization and examination of HS tissue samples. In this study, we aimed to establish a protocol for reporting histopathologic and clinical characteristics of HS tissue specimens. This study was conducted from May 2023 to August 2023. Experts in clinical care, dermatopathology, and translational research were recruited, and a modified Delphi technique was used to develop a protocol for histologic reporting and clinical characterization of submitted tissue specimens from patients with HS. A total of 27 experts participated (14 dermatologists, 3 fellowship-trained dermatopathologists, 3 plastic surgeons, 3 general surgeons, and 4 research scientists) in creating and reviewing protocols for the clinical and histopathological examination of HS tissue specimens. The protocols were formatted as a synoptic report and will help to consistently classify specimens in biobanks on the basis of histologic features and more accurately report and select samples used in translational research projects.

A systematic review of case-control studies of cytokines in blister fluid and skin tissue of patients with Stevens Johnson syndrome and toxic epidermal necrolysis.

Stevens Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are severe cutaneous adverse reactions characterised by keratinocyte apoptosis, necroptosis and epidermal detachment. Several cytokines and cytotoxic proteins have been shown to be elevated in the blood and skin of SJS/TEN sufferers and biologics such as intravenous immune globulin and tumour necrosis factor (TNF)-alpha inhibitors have demonstrated good therapeutic potential. The exact pathogenic model of SJS/TEN however remains elusive. This systematic review aimed to evaluate the case-control studies of cytokines and cytotoxic proteins in the blister fluid and skin of adults with Stevens Johnson syndrome and/or toxic epidermal necrolysis. This review was registered with INPLASY and conducted in accordance with the PRISMA reporting guidelines. Potential bias was assessed using the NIH criteria. Eleven articles describing results from 96 cases and 170 controls were included. Fas, Fas ligand, Interleukin (IL)-8 and B-cell lymphoma (Bcl)-2 were elevated in SJS/TEN blister fluid and skin tissue, compared with healthy controls. IL-2, IL-6, TNF-alpha, tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), interferon-gamma and matrix metalloproteinase-2 were elevated in SJS/TEN blister fluid compared with fluid sampled from lesional controls. Granulysin, IL-33, TGF-beta-1 and IL-13 were elevated in SJS/TEN skin tissue compared with lesional lichen planus tissue, as was IL-13, IFN-gamma, IL-2 and IL-5, when compared with erythema multiforme tissue. A wide array of cytokines and cytotoxic proteins are present at higher concentrations in the blister fluid and skin tissue of SJS/TEN patients compared with healthy and lesional controls. Our findings suggest that these proteins may be pathogenic, as well as possibly markers for diagnosis, disease severity and course. They may also prove to be useful therapeutic targets. More research is needed.

Economic Evaluation of HLA-B*15:02 Genotyping for Asian Australian Patients With Epilepsy.

Importance: The HLA-B*15:02 allele has been associated with an increased risk of carbamazepine-induced Stevens-Johnson syndrome and toxic epidermal necrolysis in specific Asian populations (including Han Chinese, Malaysian, Thai, and Vietnamese individuals). While HLA-B*15:02 genotype testing in Asian populations is recommended by several international prescribing guidelines, it is not subsidized by the Medicare Benefits Schedule in Australia. Objective: To evaluate the cost-effectiveness of HLA-B*15:02 genotyping in Asian Australian patients with epilepsy. Design, Setting, and Participants: A model with components of decision analysis and Markov simulation was developed to simulate clinical trajectories of adult Asian Australian patients with newly diagnosed epilepsy being considered for carbamazepine treatment. Cost-effectiveness and cost-utility analyses over a lifetime time horizon were conducted from the perspective of the Australian health care sector. The study was conducted in May 2023 and data analysis was performed from August 2023 to November 2023. Intervention: No HLA-B*15:02 genotyping and the empirical initiation of treatment with carbamazepine vs HLA-B*15:02 genotyping and the initiation of treatment with valproate in allele carriers. Main Outcomes and Measures: Life-years (LYs), quality-adjusted life-years (QALYs), and costs in 2023 Australian dollars (A$); incremental cost-effectiveness ratios. Results: HLA-B*15:02 screening was associated with an additional mean cost of A$114 (95% CI, -A$83 to A$374; US$76; 95% CI, -US$55 to US$248) and a reduction in 0.0152 LYs (95% CI, 0.0045 to 0.0287 LYs) but improvement by 0.00722 QALYs (95% CI, -0.0247 to -0.01210) compared with no screening, resulting in an incremental cost-effectiveness ratio of A$15 839 per QALY gained (US$10 523 per QALY). Therefore, universal genotyping for Asian Australian individuals was cost-effective compared with current standards of practice at the A$50 000 per QALY willingness-to-pay threshold. Sensitivity analyses demonstrated that the intervention remained cost-effective across a range of costs, utilities, transition probabilities, and willingness-to-pay thresholds. At the A$50 000 per QALY willingness-to-pay threshold, universal screening was the preferred strategy in 88.60% of simulations. Conclusions and Relevance: The results of this economic evaluation suggest that HLA-B*15:02 screening represents a cost-effective choice for Asian Australian patients with epilepsy who are being considered for treatment with carbamazepine.

Gram-negative anaerobes elicit a robust keratinocytes immune response with potential insights into HS pathogenesis.

Hidradenitis Suppurativa (HS) is a chronic autoinflammatory skin disease with activated keratinocytes, tunnel formation and a complex immune infiltrate in tissue. The HS microbiome is polymicrobial with an abundance of commensal gram-positive facultative (GPs) Staphylococcus species and gram-negative anaerobic (GNA) bacteria like Prevotella, Fusobacterium and Porphyromonas with increasing predominance of GNAs with disease severity. We sought to define the keratinocyte response to bacteria commonly isolated from HS lesions to probe pathogenic relationships between HS and the microbiome. Type strains of Prevotella nigrescens, Prevotella melaninogenica, Prevotella intermedia, Prevotella asaccharolytica, Fusobacterium nucleatum, as well as Staphylococcus aureus and the normal skin commensal Staphylococcus epidermidis were heat-killed and co-incubated with normal human keratinocytes. RNA was collected and analysed using RNAseq and RT-qPCR. The supernatant was collected from cell culture for protein quantification. Transcriptomic profiles between HS clinical samples and stimulated keratinocytes were compared. Co-staining of patient HS frozen sections was used to localize bacteria in lesions. A mouse intradermal injection model was used to investigate early immune recruitment. TLR4 and JAK inhibitors were used to investigate mechanistic avenues of bacterial response inhibition. GNAs, especially F. nucleatum, stimulated vastly higher CXCL8, IL17C, CCL20, IL6, TNF and IL36γ transcription in normal skin keratinocytes than the GPs S. epidermidis and S. aureus. Using RNAseq, we found that F. nucleatum (and Prevotella) strongly induced the IL-17 pathway in keratinocytes and overlapped with transcriptome profiles of HS patient clinical samples. Bacteria were juxtaposed to activated keratinocytes in vivo, and F. nucleatum strongly recruited murine neutrophil and macrophage migration. Both the TLR4 and pan-JAK inhibitors reduced cytokine production. Detailed transcriptomic profiling of healthy skin keratinocytes exposed to GNAs prevalent in HS revealed a potent, extensive inflammatory response vastly stronger than GPs. GNAs stimulated HS-relevant genes, including many genes in the IL-17 response pathway, and were significantly associated with HS tissue transcriptomes. The close association of activated keratinocytes with bacteria in HS lesions and innate infiltration in murine skin cemented GNA pathogenic potential. These novel mechanistic insights could drive future targeted therapies.

Proof-of-concept study exploring the effect of spesolimab in patients with moderate-to-severe hidradenitis suppurativa: A randomized, double-blind, placebo-controlled clinical trial.

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic inflammatory disease with a considerable disease burden. Existing treatment options are limited and often suboptimal; a high unmet need exists for effective targeted therapies. OBJECTIVE: To explore the effects of spesolimab treatment in patients with HS. METHODS: This randomized, double-blind, placebo-controlled, proof-of-clinical-concept study was conducted at 25 centers across 12 countries from May 3, 2021, to April 21, 2022. Patients had moderate-to-severe HS for ≥1 year before enrollment. Patients were randomized (2:1) to receive a loading dose of 3600 mg intravenous spesolimab (1200 mg at Weeks 0, 1, and 2) or matching placebo, followed by maintenance with either 1200 mg subcutaneous spesolimab every 2 weeks from Week 4-10 or matching placebo. The primary endpoint was the percentage change from baseline in total abscess and inflammatory nodule (AN) count at Week 12. Secondary endpoints were the absolute change from baseline in International Hidradenitis Suppurativa Severity Score System (IHS4), percentage change from baseline in draining tunnel (dT) count, the proportion of patients achieving a dT count of zero, absolute change from baseline in revised Hidradenitis Suppurativa Area and Severity Index (HASI-R), the proportion of patients achieving Hidradenitis Suppurativa Clinical Response (HiSCR50), the proportion of patients with ≥1 flare (all at Week 12), and patient-reported outcomes (PROs). RESULTS: In this completed trial, randomized patients (N=52) received spesolimab (n=35) or placebo (n=17). The difference (95% confidence interval) versus placebo in least squares mean are reported. At Week 12, the percentage change in total AN count was similar between treatment arms: -4.1% (-31.7, 23.4). There was greater numerical improvement in the spesolimab arm, as measured by IHS4: -13.9 (-25.6, -2.3); percentage change from baseline in dT count: -96.6% (-154.5, -38.8); and the proportion of patients achieving a dT count of zero: 18.3% (-7.9, 37.5). Spesolimab treatment also improved HASI-R and HiSCR50 versus placebo. Spesolimab demonstrated a favorable safety profile, similar to that observed in trials in other diseases. CONCLUSIONS: This exploratory proof-of-clinical-concept study supports the development of spesolimab as a new therapeutic option in HS. ClinicalTrials.gov identifier: NCT04762277.

Discrepancies in hidradenitis suppurativa lesion characterization by providers and patients.

BACKGROUND: The hidradenitis suppurativa (HS) clinical response (HiSCR) has come under scrutiny as several HS clinical trials failed to meet primary endpoints with high placebo responses. This may be due to limitations of the tool and raters' ability to accurately characterize and count lesions, rather than lack of efficacy of the studied drug. Due to HS lesion complexity and potential differences in rater training, it was hypothesized that there would be discrepancies in how providers characterize and count lesions for HS clinical trials. OBJECTIVE: To evaluate how HS providers and patients name and count HS lesions and to identify discrepancies among providers to initiate the development of consensus-driven guidance for HS rater training. METHODS: An online survey was distributed to the members of HIdradenitis SuppuraTiva cORe outcomes set International Collaboration (HISTORIC). Respondents were asked to classify lesion images composed of multiple and different morphology types and answer questions regarding inclusion of associated dermatological conditions. RESULTS: Forty-seven HISTORIC members responded (29 providers; 18 patients). There was variability in how respondents classified HS lesions. Of 12 questions containing images, four had ≥50% of respondents choosing the same answer. With an image of a lesion composed of different morphologies, 45% of providers counted it as a single lesion and 45% counted it as multiple distinct lesions. With an image of multiple interconnected draining tunnels, 7% of providers classified it as a single draining tunnel while 79% categorized it as multiple draining tunnels with the number estimated by visual inspection. There was also variability in deciding whether lesions occurring in associated conditions should be considered separately or included in HS lesion counts. Patient responses were also variable. CONCLUSIONS: The result of the current study reaffirms the gap in how providers characterize and count HS lesions for clinical trials and the need to develop consensus-driven rater training related to HS outcome measures.

Hidradenitis suppurativa: new insights into disease mechanisms and an evolving treatment landscape.

Hidradenitis suppurativa (HS), also known as acne inversa, is a chronic disabling and debilitating inflammatory disease with a high unmet medical need. The prevalence of HS reported in most studies is 1-2%, although it is likely to be under-reported and estimates vary globally owing to variance in data collection methods, ethnicity, geographical location and under-diagnosis. HS is characterized by persistent, painful cutaneous nodules, abscesses and draining tunnels commonly affecting the axillary, anogenital, inguinal and perianal/gluteal areas. Over time, chronic uncontrolled inflammation results in irreversible tissue destruction and scarring. Although the pathophysiology of HS has not been fully elucidated, the tumour necrosis factor (TNF)-α and interleukin (IL)-17 pathways have an important role, involving multiple cytokines. Currently, treatment options include topical medications; systemic therapies, including repeated and/or rotational courses of systemic antibiotics, retinoids and hormonal therapies; and various surgical procedures. The anti-TNF-α antibody adalimumab is currently the only biologic approved by both the US Food and Drug Administration and the European Medicines Agency for HS; however, its efficacy varies, with a clinical response reported in approximately 50% of patients in phase III trials. HS is a rapidly evolving field of discovery, with a diverse range of agents with distinct mechanisms of action currently being explored in clinical trials. Several other promising therapeutic targets have recently emerged, and agents targeting the IL-17 and Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathways are the most advanced in ongoing or completed phase III clinical trials. Alongside limited therapeutic options, significant challenges remain in terms of diagnosis and disease management, with a need for better treatment outcomes. Other unmet needs include significant diagnostic delays, thus missing the therapeutic 'window of opportunity'; the lack of standardized outcome measures in clinical trials; and the lack of established, well-defined disease phenotypes and biomarkers.

Global consensus process to establish a core dataset for hidradenitis suppurativa registries.

BACKGROUND: Several registries for hidradenitis suppurativa (HS) already exist in Europe and the USA. There is currently no global consensus on a core dataset (CDS) for these registries. Creating a global HS registry is challenging, owing to logistical and regulatory constraints, which could limit opportunities for global collaboration as a result of differences in the dataset collected. The solution is to encourage all HS registries to collect the same CDS of information, allowing registries to collaborate. OBJECTIVES: To establish a core set of items to be collected by all HS registries globally. The core set will cover demographic details, comorbidities, clinical examination findings, patient-reported outcome measures and treatments. METHODS: Beginning in September 2022, 20 participants - including both clinicians with expertise in HS and patient advocates - from eight countries across three continents participated in a Delphi process consisting of four rounds of voting, with all participants completing each round. A list of potential items for inclusion in the core set was generated from the relevant published literature, including systematic reviews of comorbidities in HS, clinical and examination findings, and epidemiology. For disease severity and progression items, the Hidradenitis SuppuraTiva Core outcome set International Collaboration (HiSTORIC) core set and other relevant instruments were considered for inclusion. This resulted in 47 initial items. Participants were invited to suggest additional items to include during the first round. Anonymous feedback was provided to inform each subsequent round of voting to encourage consensus. RESULTS: The eDelphi process established a CDS of 48 items recommended for inclusion in all HS registries globally. CONCLUSIONS: The routine adoption of this CDS in current and future HS registries should allow registries in different parts of the world to collaborate, enabling research requiring large numbers of participants.

Alterations to the Hidradenitis Suppurativa Serum Proteome with Spleen Tyrosine Kinase Antagonism: Proteomic Results from a Phase 2 Clinical Trial.

Hidradenitis suppurativa is a disease in great need of novel therapies. Given the heterogeneous nature of the disease and the variable response to therapies, biomarkers are essential to predict response to therapies and increase our understanding of disease pathogenesis. Our recent phase 2 clinical trial of spleen tyrosine kinase antagonism using fostamatinib in hidradenitis suppurativa demonstrated a 75% clinical response, with the greatest benefit in individuals with elevated serum inflammation and IgG. In this study, we present results of an in-depth serum proteomic analysis in this patient cohort identifying downregulation of IL-12B as well as B-cell-associated proteins CCL19 and CCL20 and IFN-γ-mediated proteins CXCL10 and CX3CL1. Clinical responders demonstrated greater reduction in serum IL-17A, IL-6, IL-8, and CX3CL1 compared with clinical nonresponders. Baseline levels of CCL28 were associated with clinical response to fostamatinib therapy at week 12. Overall, this suggests that fostamatinib, by targeting B-cell receptor and Fc receptor activity in B cells, monocytes, and macrophages, has a significant molecular impact on the inflammatory serum proteome of hidradenitis suppurativa. In addition, potential therapeutic biomarkers may aid in patient selection for targeted therapy.

Laser capture microdissection provides a novel molecular profile of human primary cutaneous melanoma.

Melanoma accounts for the majority of skin cancer-related mortality, highlighting the need to better understand melanoma initiation and progression. In-depth molecular analysis of neoplastic melanocytes in whole tissue biopsies may be diluted by inflammatory infiltration, which may obscure gene signatures specific to neoplastic cells. Thus, a method is needed to precisely uncover molecular changes specific to tumor cells from a limited sample of primary melanomas. Here, we performed laser capture microdissection (LCM) and gene expression profiling of patient-derived frozen sections of pigmented lesions and primary cutaneous melanoma. Compared to bulk tissue analysis, analysis of LCM-derived samples identified 9528 additional differentially expressed genes (DEGs) including melanocyte-specific genes like PMEL and TYR, with enriched of pathways related to cell proliferation. LCM methodology also identified potentially targetable kinases specific to melanoma cells that were not detected by bulk tissue analysis. Taken together, our data demonstrate that there are marked differences in gene expression profiles depending on the method of sample isolation. We found that LCM captured higher expression of melanoma-related genes while whole tissue biopsy identified a wider range of inflammatory markers. Taken together, our data demonstrate that LCM is a valid approach to identify melanoma-specific changes using a relatively small amount of primary patient-derived melanoma sample.

Human dermal fibroblast subpopulations and epithelial mesenchymal transition signals in hidradenitis suppurativa tunnels are normalized by spleen tyrosine kinase antagonism in vivo.

Hidradenitis Suppurativa is a chronic inflammatory disease of which the pathogenesis is incompletely understood. Dermal fibroblasts have been previously identified as a major source of inflammatory cytokines, however information pertaining to the characteristics of subpopulations of fibroblasts in HS remains unexplored. Using in silico-deconvolution of whole-tissue RNAseq, Nanostring gene expression panels and confirmatory immunohistochemistry we identified fibroblast subpopulations in HS tissue and their relationship to disease severity and lesion morphology. Gene signatures of SFRP2+ fibroblast subsets were increased in lesional tissue, with gene signatures of SFRP1+ fibroblast subsets decreased. SFRP2+ and CXCL12+ fibroblast numbers, measured by IHC, were increased in HS tissue, with greater numbers associated with epithelialized tunnels and Hurley Stage 3 disease. Pro-inflammatory CXCL12+ fibroblasts were also increased, with reductions in SFRP1+ fibroblasts compared to healthy controls. Evidence of Epithelial Mesenchymal Transition was seen via altered gene expression of SNAI2 and altered protein expression of ZEB1, TWIST1, Snail/Slug, E-Cadherin and N-Cadherin in HS lesional tissue. The greatest dysregulation of EMT associated proteins was seen in biopsies containing epithelialized tunnels. The use of the oral Spleen tyrosine Kinase inhibitor Fostamatinib significantly reduced expression of genes associated with chronic inflammation, fibroblast proliferation and migration suggesting a potential role for targeting fibroblast activity in HS.

Infectious Disease Screening Prior to Systemic Immunomodulatory Therapy in Hidradenitis Suppurativa: Consensus Guidelines from the Asia-Pacific Hidradenitis Suppurativa Foundation.

BACKGROUND: Current infectious disease screening recommendations for hidradenitis suppurativa (HS) are adopted from recommendations in chronic plaque psoriasis. No HS-specific guidelines for infectious disease screening prior to immunomodulatory therapy have been developed. OBJECTIVES: To establish an expert Delphi consensus of recommendations regarding infectious disease screening prior to systemic immunomodulatory therapy in HS. METHODS: Participants were identified via recent publications in the field and were sent a questionnaire regarding infectious diseases encountered in the setting of HS, and opinions regarding infectious disease screening prior to various systemic immunomodulatory therapies. All questions were informed by a systematic literature review regarding infections exacerbated or precipitated by immunomodulatory therapy. Questionnaire responses were followed by round-table discussion with a core group of 8 experts followed by a final round of questionnaires resulting in achievement of consensus. RESULTS: 44 expert HS physicians from 12 countries on 5 continents participated in the development of the expert consensus recommendations. Consensus recommendations include screening for hepatitis B, hepatitis C and tuberculosis in all individuals with HS prior to therapy. All immunomodulatory therapies (biologic and systemic immunosuppressant therapy) should be preceded by infectious disease screening including patient and location specific considerations for endemic local diseases and high-risk activities and occupations. Clinical assessment has a significant role in determining the need for laboratory screening in the setting of many uncommon or tropical diseases such as leprosy, leishmaniasis and strongyloidiasis. CONCLUSIONS: The presented consensus recommendations are the first specifically developed for pre-treatment infectious disease screening in Hidradenitis Suppurativa.