Emerging Topical and Systemic JAK Inhibitors in Dermatology

Topical delivery of baricitinib-impregnated nanoemulgel: a promising platform for inhibition of JAK -STAT pathway for the effective management of atopic dermatitis

Baricitinib, an inhibitor of Janus kinase 1/2 receptors majorly involved in the dysregulation of immune responses in atopic dermatitis, is currently approved for managing atopic dermatitis in Europe. The delivery of baricitinib through oral route is associated to several adverse effects due to off-target effects. Therefore, the current study is aimed at formulation of baricitinib loaded nanoemulgel for evaluation of topical delivery potential in the treatment of atopic dermatitis. The baricitinib-loaded nanoemulsions (0.05 and 0.1% w/w) revealed an average globule size of 162.86 ± 0.37 and 173.66 ± 4.88 nm respectively with narrow PDI. The optimized batch of baricitinib nanoemulsion was converted to nanoemulgel by the addition of the mixture of gel bases SEPINEO™ DERM and SEPINEO™ P 600 along with propylene glycol, resulting in pseudoplastic shear thinning behaviour. The optimized nanoemulgels have shown prominent retention of baricitinib in the skin along with permeation. The skin distribution study of coumarin-6 loaded nanoemulgel demonstrated high fluorescence in the epidermal layer. The western blot analysis revealed significant inhibition of phosphorylated signal transducers and activators of transcriptions 1 (##p < 0.01) and 3 (#p < 0.05) by application of 0.05 and 0.1% baricitinib nanoemulgel. The baricitinib nanoemulgels have shown anti-inflammatory activity by significantly reducing expressions of various inflammatory markers. Histopathological analysis of skin tissues treated with baricitinib nanoemulgel has demonstrated a marked reduction in acanthosis, hyperkeratosis, and intact outer epidermis. These results supported the potential role of baricitinib-loaded nanoemulgel in reducing the inflammation and disease severity associated with atopic dermatitis.

Ivarmacitinib for Moderate to Severe Atopic Dermatitis in Adults and Adolescents: A Phase 3 Randomized Clinical Trial

Importance

Ivarmacitinib, a selective oral Janus kinase 1 (JAK1) inhibitor, has demonstrated efficacy for treating adults with moderate to severe atopic dermatitis (AD) in a phase 2 trial.

Objective

To evaluate the efficacy and adverse events of ivarmacitinib in adolescents and adults with moderate to severe AD.

Design, Setting, and Participants

This multicenter, double-blind, placebo-controlled phase 3 randomized clinical trial included patients aged 12 to 75 years with moderate to severe AD. Patients were enrolled from 53 sites in Canada and China from April 2021 to April 2022. Data were analyzed from July 11 to September 27, 2023.

Interventions

Patients were randomized (1:1:1) to receive once-daily 4- or 8-mg ivarmacitinib or placebo for 16 weeks.

Main Outcomes and Measures

Co-primary end points were the proportions of patients achieving an Investigator Global Assessment (IGA) score of 0 (clear) or 1 (almost clear) with at least a 2-grade improvement from baseline and an Eczema Area and Severity Index score improvement of 75% (EASI-75) at week 16.

Results

Of 336 randomized patients (mean [SD] age, 31.1 [15.4] years; 213 [63.4%] male; 286 [85.1%] Asian), 113 received 4-mg ivarmacitinib, 112 received 8-mg ivarmacitinib, and 111 received placebo. At week 16, significantly more patients in the 4-mg ivarmacitinib group (41 of 113 [36.3%]; 95% CI, 27.5%-45.9%; P < .001) and the 8-mg ivarmacitinib group (47 of 112 [42.0%]; 95% CI, 32.7%-51.7%; P < .001) achieved an IGA score of 0 or 1 with at least a 2-grade improvement compared to the placebo group (10 of 111 [9.0%]; 95% CI, 4.4%-15.9%). EASI-75 responses were also significantly higher in the ivarmacitinib groups: 61 patients (54.0%; 95% CI, 44.4%-63.4%; P < .001) in the 4-mg group, and 74 (66.1%; 95% CI, 56.5%-74.8%; P < .001) in 8-mg group compared to 24 patients (21.6%; 95% CI, 14.4%-30.4%) in the placebo group. Treatment-emergent adverse events were reported by 78 patients (69.0%) in the 4-mg group, 74 (66.1%) in the 8-mg group, and 72 (64.9%) in the placebo group. Serious treatment-emergent adverse events occurred in 3 patients (2.7%) in the 4-mg group, 2 (1.8%) in the 8-mg group, and 3 (2.7%) in the placebo group.

Conclusions and Relevance

This phase 3 randomized clinical trial determined that once-daily ivarmacitinib demonstrated significant efficacy and a favorable risk-benefit profile for treating moderate to severe AD in adults and adolescents. These results support the potential of ivarmacitinib as a new therapeutic option.

Trial Registration

ClinicalTrials.gov Identifier: NCT04875169.

Pilot study of topical ruxolitinib demonstrates efficacy and blunting of heterogeneous inflammatory processes in mild hidradenitis suppurativa

BACKGROUND

Therapeutic options for mild hidradenitis suppurativa (HS) represent a significant gap in the current treatment landscape, with no U.S. Food and Drug Administration-approved therapies for early-stage HS. Topical Janus kinase (JAK) inhibitors (JAKi) are a compelling option due to the known upregulation of inflammatory JAK signalling in HS lesions and the recent success of systemic JAKi for the treatment of moderate-to-severe HS.

OBJECTIVES

To assess the clinical efficacy of ruxolitinib in a pilot cohort and to investigate the underlying biologic mechanisms associated with clinical response.

METHODS

This was a pilot single-site open-label prospective 24-week clinical trial of topical ruxolitinib (NCT04414514). Men and women with mild HS (Hurley stage I or II), with active inflammatory nodules, were recruited. All participants were observed for 8 weeks to monitor lesion counts (observational phase); active therapy (treatment phase) was then administered for 16 weeks. Topical ruxolitinib 1.5% cream was applied twice daily, covering the entirety of each HS-affected body site. Clinician- and patient-reported outcome measures were recorded throughout the study. Lesional skin punch biopsies were taken at the start and end of treatment for downstream mechanistic RNA sequencing and histological analyses.

RESULTS

Ten participants were enrolled in the study; four dropped out before the treatment phase of the trial. Six individuals with Hurley stage I (no tunnels) HS completed the study, five of whom successfully achieved Hidradenitis Suppurativa Clinical Response (HiSCR50) through 16 weeks of therapy. In this interim analysis, differential gene expression and gene set enrichment analyses revealed reduced activation of JAK-dependent interferon, interleukin (IL)-6, IL-2 and epidermal growth factor receptor signalling, and antimicrobial and keratinocyte responses. In contrast, signatures of wound healing and lipid metabolism were increased following JAKi treatment, indicating a return to homeostasis. Histological analyses revealed that clinically responsive patients had significantly reduced epidermal and dermal inflammation. Affected inflammatory infiltrate included neutrophils, T cells and plasma cells, with the predominantly affected cell types specific to the patient.

CONCLUSIONS

Collectively, the broad activity of topical ruxolitinib on inflammatory signalling processes resulted in promising efficacy, even with heterogeneity in baseline inflammation, in this pilot cohort. Importantly, topical treatment not only resolved epidermal inflammation, but also cleared deeper inflammatory infiltrate. The observed efficacy provides rationale to further investigate topical JAKi and other novel topical treatments in HS.

Using siRNA-Based Anti-Inflammatory Lipid Nanoparticles for Gene Regulation in Psoriasis

Background

Psoriasis is a chronic inflammatory autoimmune disease, yet it affects hundreds of millions of people. Long-term effective intervention of the disease by targeting the causative genes via RNAi (RNA interference) has become a reality. However, its further application is hindered by inflammatory side effects caused by delivery systems such as LNP (lipid nanoparticles).

Purpose

This study aimed to develop a novel anti-inflammatory LNP rationally tailored for topical application in psoriasis and to validate its potential to deliver Stat3 (signal transducer and activator of transcription 3) siRNA for the treatment of psoriasis.

Methods

To assess the transfection efficiency, anti-inflammatory capacity of LNPs. The therapeutic effect of modified anti-inflammatory LNP delivery of Stat3 siRNA on psoriasis was evaluated both in vitro and in an imiquimod-induced mice.

Results

LNPs exhibit both superior transfection efficiency and significant anti-inflammatory effects. In vitro functional studies showed that in an inflammatory DC model, anti-inflammatory LNP (C8B2) inhibited inflammatory mediators much better than classical LNPs by delivering Stat3 siRNA; in pathological HaCat cells, Stat3 siRNA reduced cell proliferation and promoted apoptosis. In the imiquimod-induced mouse model, the C8B2-si-Stat3 group demonstrated a clear reduction in psoriasis progression, whereas the C8B2 carrier group also exhibited a notable decrease in inflammation.

Conclusion

In this study, we successfully developed a novel anti-inflammatory LNP, which demonstrated notable advantages in delivery capacity, anti-inflammatory effect, and targeting therapy against STAT3, providing new ideas and strategies for nucleic acid therapy of psoriasis. This LNP platform could be broadly applicable to various inflammatory conditions, offering a versatile tool for targeted gene modulation and inflammation control.

Efficacy and safety of ritlecitinib in Asian patients with alopecia areata: A subgroup analysis of the ALLEGRO phase 2b/3 trial

This subgroup analysis of the ALLEGRO phase 2b/3 study (NCT3732807) assessed the efficacy and safety of multiple doses of ritlecitinib, an oral JAK3/TEC family kinase inhibitor, in Asian patients with alopecia areata (AA). Patients aged ≥12 years with AA and ≥50% scalp hair loss received once-daily ritlecitinib 50 or 30 mg (with or without 4-week 200-mg loading dose ["200/50" or "200/30"]) or 10 mg or placebo for 24 weeks, followed by a 24-week extension, in which patients initially assigned to placebo switched to 200/50 or 50 mg. In this subgroup analysis, Asian patients with response based on achieving a Severity of Alopecia Tool (SALT) score ≤20, SALT ≤10, ≥2-grade improvement or normal score on the eyebrow assessment (EBA) scale, and ≥2-grade improvement or normal score on the eyelash assessment (ELA) scale were evaluated through week 48. Safety was monitored throughout. In total, 186 Asian patients were randomized to ritlecitinib 200/50 mg (n = 33), 200/30 mg (n = 28), 50 mg (n = 43), 30 mg (n = 34), 10 mg (n = 17), placebo to 200/50 mg (n = 14), or placebo to 50 mg (n = 17). The proportions of patients treated with ritlecitinib ≥30 mg achieving a SALT score ≤20 response were 9.1%-36.4% at week 24 vs 0% for the 10-mg group and 3.2% for placebo. At week 48, 26.5%-55.6% of patients treated with ritlecitinib ≥30 mg achieved a SALT ≤20 response. At week 48, the proportions of patients treated with ritlecitinib ≥30 mg with EBA response were 41.9%-71.1% and with ELA response were 40.7%-57.9%. The most common adverse events were nasopharyngitis, folliculitis, upper respiratory tract infection, and urticaria. No serious or opportunistic infections, major adverse cardiovascular events, thromboembolic events, malignancies, or deaths were reported. Ritlecitinib demonstrated clinical efficacy and acceptable safety over 48 weeks in Asian patients ≥12 years with AA and ≥50% hair loss. Results for the Asian subpopulation were consistent with the overall population in the ALLEGRO-2b/3 study.

Tofacitinib in alopecia areata and HIV: A curious intersection of immunomodulation, hair regrowth, and hypertrichosis

Tofacitinib is a Janus kinase 3 (JAK3) inhibitor effective in treating alopecia areata (AA) by promoting hair regrowth. Its mechanism may involve upregulation of vascular endothelial growth factor (VEGF) and reduction of inflammation. However, the range of effects, particularly on hair growth in specific populations, remains under-investigated. We describe a patient with HIV, well-controlled on antiretroviral therapy, who developed hirsutism after starting tofacitinib for AA. This unexpected side effect of hypertrichosis was completely resolved after discontinuing the medication and undergoing a single session of laser hair removal (LHR). This case highlights the potential for unusual hair growth patterns associated with tofacitinib treatment in patients with immune dysregulation. Monitoring and management strategies for such side effects are discussed. This case highlights the potential for unusual hair growth patterns associated with tofacitinib treatment in patients with immune dysregulation. Monitoring and management strategies for such side effects are discussed. The case emphasizes the need for careful monitoring of hair growth and other potential side effects in patients on tofacitinib, especially those with underlying immune-modulating conditions. It also suggests that LHR can be an effective treatment for medication-induced hirsutism.

Efficacy and Safety of Janus Kinase Inhibitors in Patients with Vitiligo: A Systematic Review and Meta-Analysis

Although several case reports and small clinical trials have reported promising outcomes with Janus kinase (JAK) inhibitors for vitiligo, high-quality evidence and guidelines are lacking. We evaluated the efficacy and safety of JAK inhibitors for the treatment of vitiligo using a meta-analysis of randomized controlled trials (RCTs). We searched the PubMed, Embase, and Cochrane Library databases up to August 2023, with additional studies from ClinicalTrials.gov and company websites. We assessed outcomes, including percentage improvement in total vitiligo area score index (TVASI) and facial vitiligo area score index (FVASI); the proportion of patients achieving 50% improvement in TVASI (TVASI50) and 50% and 75% improvement in FVASI (FVASI50 and FVASI75); the risk of treatment-emergent adverse events (TEAEs), serious adverse events (SAEs), infections, and skin-related adverse events (AEs). Five studies with 1,550 participants were included. JAK inhibitors were associated with a higher proportion of TVASI50 (relative risk [RR] 2.67, 95% confidence interval [CI] 1.24-5.78) and FVASI75 (RR 3.97, 95%CI 2.62-6.02) responders than placebo. JAK inhibitors significantly increased the risk of skin-related AEs (RR 1.96, 95% CI 1.29-2.98) compared with placebo. However, the risk of TEAEs, SAEs, and infections was not significantly different between the JAK inhibitor and placebo groups. Subgroup analysis showed that JAK1 and JAK1/2 inhibitors were more effective than JAK3 inhibitors. However, there was insufficient evidence to suggest that the route of administration affects the efficacy and safety of JAK inhibitors in vitiligo. These findings indicate that JAK inhibitors are effective in repigmentation and well tolerated in patients with vitiligo.

Long-term safety and efficacy of ritlecitinib in adults and adolescents with alopecia areata and at least 25% scalp hair loss: Results from the ALLEGRO-LT phase 3, open-label study

BACKGROUND

ALLEGRO-LT is an ongoing, long-term, open-label, multicentre, phase 3 study of ritlecitinib in adults and adolescents with alopecia areata (AA).

OBJECTIVES

To evaluate ritlecitinib safety and efficacy through Month 24 in patients with AA and ≥25% scalp hair loss.

METHODS

ALLEGRO-LT enrolled rollover patients who previously received study intervention in either ALLEGRO phase 2a or 2b/3 studies and de novo patients who had not received treatment in either study. The de novo cohort results are reported here. Patients aged ≥12 years with AA and ≥25% scalp hair loss received a daily, 4-week 200-mg ritlecitinib loading dose, followed by daily 50-mg ritlecitinib. Analyses are based on data up to the cut-off (December 2022). Efficacy outcomes included proportions of patients achieving Severity of Alopecia Tool (SALT) scores ≤20 and ≤10, Patient Global Impression of Change (PGI-C) score of 'moderately improved' or 'greatly improved' and eyebrow assessment (EBA) and eyelash assessment (ELA) response (≥2-grade improvement from baseline or normal score in patients with abnormal baseline EBA/ELA).

RESULTS

Mean (SD) ritlecitinib exposure among the 449 de novo patients enrolled was 728.7 (273.81) days. At Month 24 (as observed), 73.5% and 66.4% of patients achieved SALT score ≤20 and ≤10; 82.4% had PGI-C response; 60.8% and 65.7% had EBA and ELA response. 86.1% of patients reported treatment-emergent adverse events (AEs); most were mild or moderate in severity, with the most frequent being positive SARS-CoV-2 test (24.2%), headache (20.8%) and pyrexia (13.0%). Rates of serious AEs, severe AEs and treatment discontinuations were 4.9%, 6.0% and 6.5%, respectively. Herpes zoster infection occurred in six patients, serious infections in four, malignancies (excluding nonmelanoma skin cancer) in three and major adverse cardiovascular events in three.

CONCLUSIONS

In patients with AA and ≥25% scalp hair loss, ritlecitinib demonstrated clinical efficacy and had an acceptable safety profile with long-term treatment.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov NCT04006457.

Innovative Approaches to Psoriasis: Small Molecules Targeting Key Signaling Pathways

BACKGROUND

Psoriasis (Pso) is a chronic, immune-mediated dermatological condition characterized by dysregulated inflammatory responses and the hyperproliferation of keratinocytes. Biologics, which target specific cytokines such as IL-17 and IL-23, have revolutionized the management by addressing key drivers of its pathophysiology. Despite their efficacy, biologics are not without limitations, including the need for intermittent administration and ongoing monitoring. In contrast, small molecules offer a promising alternative by selectively inhibiting key signaling pathways that modulate pro-inflammatory cytokines involved in the inflammatory cascade.

METHODS AND RESULTS

This review suggests a new therapeutic strategy for Pso treatment, emphasizing the intricate relationships between small molecules and important signaling pathways involved in the pathophysiology of skin conditions. Improving treatment outcomes and reducing the side effects associated with conventional medicines, this review aims to better understand how tailored small-molecule inhibitors might efficiently control these pathways. This creative approach promotes the creation of individualized treatment plans that can greatly enhance the quality of life of patients with Psoby utilizing the knowledge gathered from recent developments in signaling pathway research.

CONCLUSION

This review delves into the molecular mechanisms underlying Pso and explores how small molecules can be harnessed to enhance treatment outcomes, presenting a new paradigm for managing this chronic skin disorder.

Update vulval dermatology - diagnostics and therapy

The vulva is a periorificial skin area and as such represents a transitional zone with unique functional and physiological characteristics. Knowledge of its anatomy is limited among both the general population and healthcare professionals, and unrealistic expectations of normal proportions are common. Ignorance of anatomical variations can cause unnecessary anxiety. In Germany, specialists in gynecology and obstetrics most commonly treat neoplastic vulvar dermatoses, while chronic inflammatory dermatoses commonly affecting the female genitalia (such as psoriasis, atopic dermatitis, hidradenitis suppurativa, and vitiligo) are typically treated by dermatologists. Both specialties treat infectious vulvar dermatoses and sexually transmitted infections. Certain dermatoses, such as lichen sclerosus, lichen planus, and lichen simplex chronicus, tend to affect the vulva preferentially; however, terminology can be confusing. Therefore, this article provides basic information on vulvar anatomy and physiology and summarizes recommendations for the diagnosis and management of the most common vulvar dermatoses, with a special focus on chronic inflammatory dermatoses, to provide a useful guide for all involved specialists in daily practice. Interdisciplinary collaboration and the establishment of dedicated consultation hours may help to improve the clinical care of vulvar dermatoses.

Neuroinflammatory pathways and potential therapeutic targets in neonatal post-hemorrhagic hydrocephalus

BACKGROUND

Post-hemorrhagic hydrocephalus (PHH) is a severe complication in premature infants following intraventricular hemorrhage (IVH). It is characterized by abnormal cerebrospinal fluid (CSF) accumulation, disrupted CSF dynamics, and elevated intracranial pressure (ICP), leading to significant neurological impairments.

OBJECTIVE

This review provides an overview of recent molecular insights into the pathophysiology of PHH and evaluates emerging therapeutic approaches aimed at addressing its underlying mechanisms.

METHODS

Recent studies were reviewed, focusing on molecular and cellular mechanisms implicated in PHH, including neuroinflammatory pathways, immune mediators, and regulatory genes. The potential of advanced technologies such as whole genome/exome sequencing, proteomics, epigenetics, and single-cell transcriptomics to identify key molecular targets was also analyzed.

RESULTS

PHH has been strongly linked to neuroinflammatory processes triggered by the degradation of blood byproducts. These processes involve cytokines, chemokines, the complement system, and other immune mediators, as well as regulatory genes and epigenetic mechanisms. Current treatments, primarily surgical CSF diversion, do not address the underlying molecular pathology. Emerging therapies, such as mesenchymal stem cell-based interventions, show promise in modulating immune responses and mitigating neurological damage. However, concerns about the safety of these novel approaches in neonatal populations and their potential effects on brain development remain unresolved.

CONCLUSIONS

Advanced molecular tools and emerging therapies have the potential to transform the treatment of PHH by targeting its underlying pathophysiology. Further research is needed to validate these approaches, enhance their safety profiles, and improve outcomes for infants with PHH.

IMPACT STATEMENT

1. This review elucidates the molecular complexities of post-hemorrhagic hydrocephalus (PHH) by examining specific immune pathways and their impact on disease pathogenesis and progression. 2. It outlines the application of genomic, epigenomic, and proteomic technologies to identify critical molecular targets in PHH, setting the stage for innovative, targeted therapeutic approaches that could improve the outcomes of neonates affected by PHH. 3. It discusses the potential of gene and stem cell therapies in treating PHH, offering non-surgical alternatives and focusing on the underlying neuroinflammatory mechanisms.

Natural Modulators of Key Signaling Pathways in Skin Inflammageing

Low-grade chronic inflammation without obvious infection is defined as "inflammageing" and a key driver of skin ageing. Although the importance of modulating inflammageing for treating skin diseases and restoring cutaneous homeostasis is increasingly being recognized. However, the mechanisms underlying skin inflammageing, particularly those associated with natural treatments, have not been systematically elucidated. This review explores the signaling pathways associated with skin inflammageing, as well as the natural plants and compounds that directly or indirectly target these pathways. Nine signaling pathways and 60 plants/constituents related to skin anti-inflammageing are discussed, exploring plant mechanisms to mitigate skin inflammageing. Common natural plants with anti-inflammageing activity are detailed by active ingredients, mechanisms, therapeutic potential, and quantitative effects on skin inflammageing modulation. This review strengthens our understanding of these botanical ingredients as natural interventions against skin inflammageing and provides directions for future research.

Upadacitinib for the management of bullous pemphigoid coexisting with psoriasis vulgaris: a case report and literature review

Both bullous pemphigoid (BP) and psoriasis are common immune-related dermatological conditions in clinical practice, but the co-occurrence of these two diseases is rare. Currently, there is no consensus on the long-term safe and effective treatment for patients with both BP and psoriasis. JAK inhibitors are emerging as targeted therapeutic drugs that act by inhibiting Janus kinase activity, regulating the JAK/STAT pathway, blocking the transduction pathway of key proinflammatory cytokines, and influencing T-cell differentiation. These cytokines upstream of the JAK/STAT pathway play a pivotal role in the pathogenesis of numerous inflammatory and autoimmune disorders. Upadacitinib, a second-generation JAK inhibitor with high selectivity, demonstrates promising potential.This case report aims to provide a description of the successful treatment of bullous pemphigoid (BP) and psoriasis vulgaris by using upadacitinib, highlighting significant clinical outcomes. Additionally, we aim to analyze the underlying mechanism of upadacitinib in treating these two comorbidities by reviewing relevant literature from both domestic and international sources. Based on our clinical observations, upadacitinib appears to be a promising and well-tolerated therapeutic option for patients with concurrent BP and psoriasis, offering valuable insights for developing appropriate treatment strategies in clinical practice.

Quantitative analysis of JAK/STAT signaling pathway in patients of inflammatory skin disorders

BACKGROUND

Inflammatory skin diseases (ISDs), are characterized by dysregulated activation of innate and adaptive immune systems, with inflammatory cytokines playing a crucial role in their pathogenesis.

OBJECTIVES

This study aimed to investigate the involvement of Janus kinase/signal transduction and activator of transcription (JAK/STAT) signaling pathway in the pathogenesis of ISDs.

METHODS

The study analyzed a total of 117 skin biopsies, comprising 31 from pyoderma gangrenosum (PG), 25 from hidradenitis suppurativa (HS), 35 from psoriasis patients, and 26 from control subjects. To assess the expression levels of JAK/STAT pathway components, immunohistochemical staining was performed on both the dermal and epidermal layers of the skin. The Histo score (H score) was utilized as the immunoexpression score to evaluate the staining intensity.

RESULTS

The results indicated that all components of the JAK/STAT signaling pathway, except JAK2 and STAT6 in PG, JAK1, STAT4, and STAT6 in HS, and JAK1 in psoriasis, were overexpressed in the dermal skin compared to the control group (p < 0.05). Psoriatic skin had higher expression of STAT6 than both PG and HS and higher expression of JAK2 than PG (p < 0.05). Additionally, HS biopsies had higher expression of JAK2 and STAT6 compared to PG (p < 0.05). JAK1 expression was higher in PG than in HS, psoriasis, and the control group (mean H score was 265.8, 184.8, 191.4, and 113.1, p < 0.05, respectively).

CONCLUSIONS

This study provides new insights into the potential contribution of the JAK/STAT pathway to the pathogenesis of ISDs. The findings suggest that targeting this pathway could be a promising therapeutic strategy for treating these disorders.

Changes and significance of Th1/Th2 and Treg/Th17 cells and their cytokines in patients with alopecia areata

BACKGROUND

Alopecia areata (AA) is a chronic autoimmune disease. Th1/Th2 and Treg/Th17 cells and their cytokines are implicated in AA, and we explored their clinical significance in AA.

METHODS

AA patients and healthy people (controls) were enrolled, with their Th1/Th2/Th17/Treg cell proportion changes and serum Th1 (INF-γ)/Th2 (IL-5, IL-6)/Th17 (IL-17, IL-22)/Treg (IL-35) cytokine levels assessed. AA patients were assigned into mild, moderate and severe alopecia according to Severity of Alopecia Tool (SALT). The relationship between alopecia severity and initial onset age, disease course, family/smoking/drinking history and sleep disorders was explored. Th1/Th2 and Treg/Th17 cells and their cytokine levels in AA patients with different severity levels were compared. The correlation between cytokine levels and SALT scores was analyzed using Spearman. Additionally, the changes of serum cytokine levels in inactive/active AA patients were compared.

RESULTS

AA patients differed from controls in family history/smoking history/drinking history/sleep disorders. Peripheral blood Th1/Th2/Th17 cell proportions and INF-γ/IL-5/IL-6/IL-17/IL-22 levels increased, while Treg cell proportions and IL-35 level dropped. With higher alopecia severity, the proportions of Th1, Th2 and Th17 cells increased, and Treg cell proportion decreased. AA patients with mild/moderate alopecia had significant differences in IL-17 level. Serum INF-γ, IL-5, IL-17 and IL-22 levels were elevated, and IL-35 level dropped in severe AA patients versus moderate AA patients.

CONCLUSION

Th1/Th2/Th17 cell proportions and serum INF-γ/IL-5/IL-6/IL-17/IL-22 levels in AA patients were up-regulated, while Treg cell proportion and IL-35 level were repressed. SALT scores were positively-correlated with serum IL-5/IL-17 levels. SALT scores were negatively-correlated with serum IL-35.

Cannabidiol Alleviates Imiquimod-Induced Psoriasis by Inhibiting JAK2-STAT3 in a Mouse Model

Cannabidiol (CBD), a non-psychoactive compound from Cannabis sativa, has shown efficacy in treating psoriasis, a chronic inflammatory skin disease affecting 1-3% of the global population; however, the mechanisms remain unclear. This study investigated CBD's effects on imiquimod (IMQ)-induced psoriasis in mice, which were divided into five groups: Control, IMQ, Clobetasol, 0.01% CBD, and 0.1% CBD. After inducing psoriasis with IMQ, clobetasol or CBD was applied. Psoriasis severity was assessed using the Psoriasis Area and Severity Index (PASI), with histopathological changes examined via hematoxylin and eosin staining. Gene expression of inflammatory markers (Il1b, Il6, Il12b, Il17a, Il22, and Tnf) was analyzed by RT-PCR, while protein levels of signal transducer and activator of transcription (STAT)3, P-STAT3, Janus kinase (JAK)2, and JAK3 were evaluated through western blot and immunohistochemistry. The results demonstrated that CBD significantly reduced PASI scores, epidermal thickness, keratosis, hyperproliferation, and inflammation. Moreover, CBD inhibited the IL-23 receptor-mediated JAK2-STAT3 signaling pathway, leading to the downregulation of Il1b, Il6, Il12b, Il17a, Il22, and Tnf expression. These findings suggest that CBD effectively alleviates psoriasis-like symptoms in mice and may serve as a promising therapeutic agent for psoriasis by targeting the JAK2-STAT3 pathway.

Sappanone A ameliorated imiquimod-induced psoriasis-like dermatitis in BALB/c mice via suppressing Mmp8 expression and IL-17 signaling pathway

Psoriasis is a prevalent immune-mediated inflammatory skin disease characterized by excessive abnormal proliferation of keratinocytes and infiltration of immune cells, which have significant impact on the life quality of individuals. Although biological agents and small molecule targeted drugs have brought significant clinical benefits to psoriasis patients, adverse reactions and high prices remains key issues in clinical medication of psoriasis, while natural product monomers possess high efficiency, low toxicity, anti-inflammatory and immunomodulatory properties, and bring new hope for the clinical treatment of psoriasis. Sappanone A (SA), a small molecule compound isolated from Caesalpinia sappan L, exhibits significant anti-inflammatory properties in various models, such as kidney inflammation and LPS-induced mice inflammation. Among these effects, the anti-inflammatory property of SA has received significant attention. In our study, we found that SA exhibited anti-proliferation and anti-inflammatory effects in HaCaT cells, and significantly alleviated imiquimod-induced psoriasis-like skin lesions via the inhibition of the excessive proliferation of keratinocytes and the infiltration of lymphocytes. Furthermore, the combinational analysis of network pharmacology and transcriptome sequencing revealed that SA exerted anti-psoriasis effects by inhibiting the matrix metalloproteinase 8 (Mmp8) expression and IL-17 pathway activation. In summary, we have first demonstrated that SA can be used as a novel anti-psoriasis drug, which may provide a novel strategy for the clinical treatment of psoriasis.

Remission of refractory esophageal lichen planus induced by tofacitinib

As of now, there exists no established therapy for ELP. Retinoids, which are standard in treating cutaneous LP, do not exhibit positive effects in ELP. While topical glucocorticosteroids often yield favorable responses in esophageal inflammation, some cases prove recalcitrant or refractory. In such instances, various immunosuppressive therapies have been attempted with variable success.This report details a severe case of ELP that showed resistance to prednisolone, acitretin, alitretinoin, adalimumab, tacrolimus, hydroxychloroquine plus mycophenolate mofetil, and cyclophosphamide. The initiation of the JAK inhibitor tofacitinib induced an impressive clinical, endoscopic, and histological remission. This positive response to a JAK inhibitor is discussed in the context of our evolving understanding of the immune-mediated pathogenesis of this disease.

The treatment of Tofacitinib for rosacea through the inhibition of the JAK/STAT signaling pathway

Rosacea is a chronic inflammatory skin disease characterized by facial erythema and telangiectasia. Despite ongoing research, the pathogenesis of rosacea remains incompletely understood, and current therapies are not entirely satisfactory. The JAK/STAT signaling pathway plays an essential role in immunoregulation, inflammation, and neurovascular regulation. Inhibition of the JAK/STAT pathway appears to hold promise as a potential therapy for rosacea. This study aimed to investigate the effects of the JAK inhibitor tofacitinib on rosacea and to preliminarily explore its therapeutic mechanism. To this end, a rosacea-like mouse model was induced using LL37 and treated with a 2% tofacitinib emulsion. The results demonstrated that topical application of tofacitinib significantly ameliorated rosacea-like phenotype, reduced the infiltration of CD4+ T cells and mast cells, and suppressed dermal angiogenesis. RT-qPCR analysis revealed a reduction in mRNA expression levels of STAT1, STAT4, and STAT5a in skin lesions following topical tofacitinib treatment. Additionally, three patients diagnosed with erythematotelangiectatic rosacea (ETR) were included in the study and treated with oral tofacitinib, leading to a significant improvement in erythema and flushing symptoms. These findings collectively suggest that tofacitinib alleviates LL37-induced rosacea-like skin inflammation in mice and rosacea skin lesions by inhibiting the JAK/STAT signaling pathway.

Treatment of Lichen Planopilaris and Frontal Fibrosing Alopecia: A Retrospective, Real-Life Analysis in a Tertiary Center in Germany

Background: Lichen planopilaris (LPP) is an inflammatory cicatricial alopecia characterized by an irreversible destruction of the hair follicle resulting in its permeant destruction. The clinical presentation of LPP is a progressive patchy scarring alopecia. A variety of systemic agents is used to treat LPP with varying success. The aim of this retrospective, real-life analysis was to evaluate the treatment of hydroxychloroquine for LPP. Method: In this retrospective, single-center study, we analyzed 110 patients with LPP and frontal fibrosing alopecia (FFA) who received treatment over a 12-month period from March 2014 to March 2021 at the Department of Dermatology, University of Mainz Medical Center. Patient records were analyzed for response to treatment, co-morbidities, disease progression-free survival (DPFS), and safety. Clinical parameters associated with treatment response were determined with Cox regression modelling and logistic regression. Results: Overall, 77 of 110 patients were treated with a systemic agent. There was a clear association between LPP and the occurrence of Hashimoto thyroiditis. Topical treatment with corticosteroids did not improve clinical symptoms in the majority of patients (15 out of 101). In 71% of patients treated with systemic cyclosporine A and 62% of patients treated with hydroxychloroquine, we observed a significant resolution of the inflammatory process, which correlated with a robust durable clinical response (p < 0.001). Toxicity was observed in 17% (n = 9) of patients receiving systemic treatment with hydroxychloroquine and correlated with the duration of systemic treatment (p < 0.001). Treatment discontinuation was associated with a flare-up of clinical symptoms (29%), which required the re-initiation of second-line therapy in 13 out of 51 patients. Overall, the initiation of second-line treatment, either hydroxychloroquine or Cyclosporine A (CsA), yielded positive results, especially in the patient cohort treated with hydroxychloroquine (overall response rate, ORR = 100%), who showed disease progression during CsA or retinoids. Conclusions: Our results from this contemporary cohort of patients with LPP and FFA indicate that hydroxychloroquine and cyclosporine are effective systemic agents in decreasing clinical symptoms. However, our data also show that the discontinuation of treatment is often associated with the exacerbation of clinical symptoms. Response rates to second-line treatment were especially favorable in the patient cohort with hydroxychloroquine.

Exploring the Complexities of Atopic Dermatitis: Pathophysiological Mechanisms and Therapeutic Approaches

Atopic dermatitis (AD) is a prevalent inflammatory skin condition impacting both children and adults globally, with a prevalence of 15-30%. It ranks as the most prevalent skin disorder based on disability-adjusted life-years by the World Health Organization. It presents with symptoms like skin irritation, redness, dryness, itchiness, and vesicular blisters and commonly coexists with other atopic symptoms like allergic rhinitis, asthma, and food allergies. The pathophysiology involves a complex interplay of genetic predispositions, immunological dysfunctions, and environmental factors leading to tissue inflammation and disrupted skin barrier integrity. Alopecia areata is characterized by nonscarring hair loss and shares correlations with AD including a higher prevalence of atopic diseases, shared intracellular mechanisms involving the JAK-STAT pathway, and potential treatment overlap such as dupilumab. These correlations could direct new areas of research and increased insight for both diseases. Treatment of AD requires a personalized approach due to its complex, multifactorial nature integrating nonpharmacological interventions like skin hydration and trigger avoidance as well as topical and systemic approaches, if necessary, with topical corticosteroids being the first line for flares; long term corticosteroid use poses risk for adverse effects like skin atrophy. Severe cases may require systemic treatments or phototherapy. Future treatment prospects include targeting the dysbiotic microbiome and identifying biomarkers for tailored therapeutic strategies, emphasizing the importance of personalized medicine in optimizing AD management.

CS12192, a novel JAK3/JAK1/TBK1 inhibitor, attenuates autoimmune dermatoses in murine models

OBJECTIVE

Autoimmune dermatosis (AID) occurs when the body's immune system attacks skin or tissue, leading to various types of skin disorders or injuries. Recent studies show that Janus kinases (JAKs) play critical roles in autoimmune diseases including AID by regulating multiple cytokine signaling pathways. CS12192, a novel JAK3/JAK1/TBK1 inhibitor, has been reported to exert ameliorative effects in rheumatoid arthritis. However, the efficacy of CS12192 on AID is undetermined. This study aims to investigate the therapeutic efficacy of CS12192 on psoriasis (PSO), systemic lupus erythematosus (SLE) and atopic dermatitis (AD) in mouse models.

METHODS

Interleukin-23 (IL-23)-induced PSO model, spontaneous SLE model of MRL/MpJ-Faslpr/J (MRL/lpr) mice, and oxazolone (OXA) and dinitrochlorobenzene (DNCB)-induced murine AD models were used for the evaluation of curative effects of CS12192, respectively. The skin lesion, biochemical parameters, ear thickness, ear weight and histopathology were assessed accordingly.

RESULTS

In PSO model, mice treated with CS12192 show reduced ear thickness and ear weight as compared with vehicle. In SLE model, CS12192 ameliorates cutaneous parameters such as lymphadenectasis and skin lesion but not systematic parameters such as proteinuria concentration and score, serum dsDNA and BUN concentration. In AD models, CS12192 dose-dependently improves ear swelling and reduces histological scores, exerting equivalent efficacy with baricitinib, a marketed JAK1/JAK2 inhibitor.

CONCLUSION

Our findings suggest that the novel JAK3/JAK1/TBK1 inhibitor CS12192 is potentially to alleviate autoimmune dermatosis.

A novel approach with tofacitinib for the management of keratoderma blennorrhagicum in reactive arthritis: a case report

Reactive arthritis(ReA), a form of arthritis occurring post-infection, manifests with antecedent infection symptoms, arthritis, and extra-articular manifestations, categorizing it as spondyloarthritis. "Keratoderma blennorrhagicum" (characterized by pustular hyperkeratosis on palms and soles, resembling pustular psoriasis) represents the most typical skin manifestation of ReA, occurring in acute or chronic phases. Severe lesions necessitate systemic disease modifying anti-rheumatic drugs (DMARDs) or biologic therapies. This article reports a case of ReA with sacroiliitis and widespread pustular eruptions following a urinary tract infection. Treatment with sulfasalazine and thalidomide significantly improved sacroiliitis, but the skin rash remained persistent and recurring. Subsequent use of adalimumab and secukinumab resulted in worsening skin rash, prompting a switch to tofacitinib, leading to a remarkable improvement in pustular eruptions after 20 days of treatment. This case demonstrates successful application of tofacitinib in treating severe keratoderma blennorrhagicum refractory to conventional DMARDs and biologics, offering insights into JAK inhibition for challenging rheumatic diseases with skin involvement.

Pharmacological Trends in the Management of Atopic Dermatitis: A Comprehensive Review

Atopic dermatitis (AD) is a prevalent, chronic inflammatory skin condition characterized by pruritus, erythema, and impaired skin barrier function. AD management presents significant challenges due to its complex pathophysiology involving immune dysregulation and genetic predispositions. While traditional therapies, such as topical corticosteroids and emollients, remain foundational, their limitations have spurred the development of novel pharmacological approaches. This comprehensive review explores current pharmacological trends in the management of AD, focusing on emerging therapies that target specific immunological pathways. Biologic agents, including monoclonal antibodies against interleukin (IL)-4, IL-13, and IL-31 receptors, offer targeted mechanisms to modulate immune responses implicated in AD pathogenesis. Janus kinase (JAK) and phosphodiesterase-4 (PDE-4) inhibitors represent another class of promising therapies, providing alternatives for patients resistant to conventional treatments. The review synthesizes evidence from clinical trials and studies to evaluate these pharmacological agents' efficacy and safety profiles. Considerations for personalized medicine approaches, including biomarkers for treatment response prediction and genotype-based therapies, are discussed to highlight the potential for tailored treatment strategies in AD management. In conclusion, this review underscores the evolving landscape of pharmacological interventions for AD, emphasizing the need for continued research to address unmet clinical needs and optimize patient outcomes. By delineating current advancements and future directions, this review aims to inform clinical practice and guide future research endeavours in dermatology.

Patient-Reported Satisfaction with Hair Regrowth in a Study of Ritlecitinib in Alopecia Areata: Results from ALLEGRO-2b/3

INTRODUCTION

Patients with alopecia areata (AA) report high levels of dissatisfaction with commonly used treatments. Patient-reported outcomes are essential to understanding patients' experiences with AA treatments. The objective of this study was to evaluate patient-reported satisfaction with hair growth among patients with AA receiving ritlecitinib or placebo and the correlation between clinician-assessed efficacy and patient-reported satisfaction.

METHODS

In the ALLEGRO-2b/3 (NCT03732807) trial, patients with AA and ≥50% scalp hair loss were randomized to daily ritlecitinib or placebo for 24 weeks, with a 24-week extension of continued ritlecitinib or switch from placebo to ritlecitinib. The Patient Satisfaction with Hair Growth (P-Sat) measure evaluated patients' satisfaction with hair growth in 3 domains: amount, quality, and overall satisfaction with hair growth. The prespecified analysis evaluated the proportion of patients who were slightly, moderately, or very satisfied with hair growth. Several post hoc analyses assessed the proportion of patients who were moderately/very satisfied and moderately/very dissatisfied and calculated polyserial correlations between change from baseline (CFB) in Severity of Alopecia Tool (SALT) and P-Sat scores at weeks 24 and 48.

RESULTS

At week 24, the proportion of patients (N = 718) reporting satisfaction (slightly, moderately, or very satisfied) overall with their hair growth ranged from 36.4% in the ritlecitinib 10-mg group (evaluated for dose ranging only) to 67.5% in the 200/50-mg group versus 22.6% in the placebo groups. In patients randomized to ritlecitinib, the proportion who were satisfied increased or was maintained at week 48. A substantially greater proportion of placebo patients who switched to ritlecitinib reported satisfaction at week 48 than at week 24. Similar results were observed for patient satisfaction with the amount and quality of hair growth. In the post hoc analyses defining satisfaction as moderately/very satisfied and dissatisfaction as moderately/very dissatisfied, the benefit of ritlecitinib was also observed. All P-Sat domain scores strongly correlated with CFB-SALT scores at weeks 24 (range 0.73-0.76; p < 0.05) and 48 (0.74-0.77; p < 0.05).

CONCLUSIONS

Patients receiving active ritlecitinib doses reported favorable results versus placebo in satisfaction with hair growth up to week 48. High concordance was observed between improvement in scalp hair growth evaluated by clinicians and patient-reported satisfaction.

A bidirectional autoimmune cluster between vitiligo and rheumatoid arthritis: a large-scale population-based study

A knowledge gap exists regarding the association between vitiligo and rheumatoid arthritis (RA) due to the absence of large-scale cohort studies designed to investigate this association. To investigate the bidirectional epidemiological association between vitiligo and RA. A population-based study was conducted using Clalit Health Services (CHS) database (2002-2019) using both a cohort study and a case-control study design. Adjusted hazard ratio (HR) and odds ratio (OR) were calculated by multivariate Cox and logistic regressions, respectively. Overall, 20,851 vitiligo patients and 102,475 controls were included. The incidence of new-onset RA was 4.1 (95% CI 3.0-5.4) and 2.9 (95% CI 2.4-3.3) cases per 10,000 person-years among patients with vitiligo and controls, respectively. Patients with vitiligo had a significantly increased risk of developing new-onset RA (adjusted HR, 1.44; 95% confidence interval [CI], 1.02-2.02, P = 0.036). The likelihood of having vitiligo was significantly elevated after a preexisting diagnosis of RA (adjusted OR, 1.67; 95% CI, 1.38-2.03; P < 0.001). Relative to the remaining patients with vitiligo, those with vitiligo and comorbid RA demonstrated an elevated risk of all-cause mortality (adjusted HR, 1.61; 95% CI, 1.03-2.51; P = 0.037). Our study confirms the bidirectional association between vitiligo and RA. Physicians treating patients with vitiligo should be aware of the association in clinical practice.

Case report: Hypertrophic lichen planus initially misdiagnosed as squamous cell carcinoma

Fewer than 26 case reports describe hypertrophic lichen planus (HLP) misdiagnosed as cutaneous squamous cell carcinoma (cSCC). It can be difficult to distinguish between HLP and cSCC, as these two conditions share many clinical and histopathological characteristics. Patients who are misdiagnosed with cSCC often undergo unnecessary medical and/or surgical interventions before receiving a diagnosis of HLP and improving on HLP-directed therapy. This case series highlights the course of three female patients, referred to a single tertiary institution between 2018 and 2022, who were initially misdiagnosed with cSCC before receiving a diagnosis of HLP. We have emphasized the clinical and histopathological distinguishing features between HLP and cSCC, the pathogenesis of HLP, and current and new HLP-directed therapy. We hope that this case series serves as a reminder to dermatologists, dermatologic surgeons, and dermatopathologists to be aware of this diagnostic challenge.

JAK/STAT Inhibition Normalizes Lipid Composition in 3D Human Epidermal Equivalents Challenged with Th2 Cytokines

Derangement of the epidermal barrier lipids and dysregulated immune responses are key pathogenic features of atopic dermatitis (AD). The Th2-type cytokines interleukin IL-4 and IL-13 play a prominent role in AD by activating the Janus Kinase/Signal Transduction and Activator of Transcription (JAK/STAT) intracellular signaling axis. This study aimed to investigate the role of JAK/STAT in the lipid perturbations induced by Th2 signaling in 3D epidermal equivalents. Tofacitinib, a low-molecular-mass JAK inhibitor, was used to screen for JAK/STAT-mediated deregulation of lipid metabolism. Th2 cytokines decreased the expression of elongases 1, 3, and 4 and serine-palmitoyl-transferase and increased that of sphingolipid delta(4)-desaturase and carbonic anhydrase 2. Th2 cytokines inhibited the synthesis of palmitoleic acid and caused depletion of triglycerides, in association with altered phosphatidylcholine profiles and fatty acid (FA) metabolism. Overall, the ceramide profiles were minimally affected. Except for most sphingolipids and very-long-chain FAs, the effects of Th2 on lipid pathways were reversed by co-treatment with tofacitinib. An increase in the mRNA levels of CPT1A and ACAT1, reduced by tofacitinib, suggests that Th2 cytokines promote FA beta-oxidation. In conclusion, pharmacological inhibition of JAK/STAT activation prevents the lipid disruption caused by the halted homeostasis of FA metabolism.

TYK2 inhibition with deucravacitinib ameliorates erosive oral lichen planus

Erosive oral lichen planus (OLP) is a challenging disease. This T cell driven disorder frequently shows a treatment unresponsive course and strongly limits patients' quality of life. The disease lacks FDA or EMA approved drugs for its treatment and the efficacy of the commonly administered treatments (i.e. topical and systemic steroids, steroid sparing agents) is often only partial. Although the etiopathogenesis of the disease still needs to be fully elucidated, recent advances helped to identify interferon-ɣ (IFN-ɣ) as a pivotal cytokine in OLP pathogenesis, thus making the interference with its signalling a therapeutic target. Janus kinase (JAK) inhibitors therefore gained relevance for their inhibitory effect on IFN-ɣ signalling. While some drugs such as abrocitinib, upadacitinib, tofacitinib directly interfere with IFN-ɣ signalling through blockade of JAK1 and/or JAK2, deucravacitinib, a selective TYK-2 inhibitor indirectly interferes on IFN-ɣ activation through interference with interleukin (IL)-12, a potent promotor for Th1/IFN-ɣ responses. This mechanism of action makes deucravacitinib a candidate drug for the treatment of OLP. Here we provide initial evidence that deucravacitinib 6 mg daily has a beneficial effect in three patients with oral OLP.

Serum cytokine profiles predict response to systemic glucocorticoid in active vitiligo

Introduction

Vitiligo is an immune-related skin disease. Cytokines regulate immune response and inflammation and are involved in the pathogenesis of vitiligo.

Aim

To assess the serum levels of pro-inflammatory cytokines pre- and post- systemic glucocorticoid treatment in patients with active vitiligo.

Material and methods

We measured serum cytokine levels using the enzyme-linked immunosorbent assay in 31 patients with active vitiligo before and after treatment. All patients received systemic glucocorticoid (compound betamethasone injection) in combination with topical halometasone cream and tacrolimus ointment for 3 months. Twenty healthy controls were also examined. The cytokines measured included TNF-α, IL-1β, IL-6, IFN-γ, IL-2, IL-17, IL-10, IL-8, and CXCL10.

Results

The serum levels of TNF-α, IL-1β, IL-6, IFN-γ, IL-2, IL-17, IL-8, and CXCL10 were significantly higher, and levels of IL-10 were lower in vitiligo patients compared to controls. Additionally, serum IFN-γ (r = 0.378; p = 0.036), IL-17 (r = 0.426; p = 0.017), and CXCL10 (r = 0.514; p = 0.003) showed a positive correlation with affected body surface area in vitiligo patients. After 3 months of systemic glucocorticoid treatment, the levels of IL-1β, IFN-γ, IL-2, IL-17, and CXCL10 in responders were significantly decreased and nearly restored to normal levels. The IL-10 level was also increased in response to treatment. In contrast, the non-responder group had persistently high IL-6, IL-17, IL-8, and CXCL10 levels, and negligible changes in TNF-α, IL-1β, IFN-γ, IL-2, and IL-10.

Conclusions

Our study indicated that the levels of inflammatory cytokines were significantly ameliorated in the glucocorticoid responder group. Altered cell-mediated immunity may contribute to the resistance in vitiligo. The cytokines such as TNF-α, IL-1β, IFN-γ and IL-2 could serve as therapeutic targets for managing glucocorticoid-resistant vitiligo.

A Case of Vitiligo Combined with Systemic Lupus Erythematosus Treated with Tofacitinib

Vitiligo is a skin depigmentation disease resulting from melanocyte destruction and often co-occurring with autoimmune disorders like hyperthyroidism, alopecia areata, pernicious anemia, and systemic lupus erythematosus (SLE). Although various traditional treatments exist for vitiligo, their effectiveness varies considerably. This report presents a unique case of a vitiligo patient with concomitant systemic lupus erythematosus. Remarkably, after a 30-day course of treatment with tofacitinib, complete repigmentation of the white macular rash was achieved, and there were no adverse drug reactions. These findings provide compelling evidence for the efficacy and safety of oral JAK inhibitors, such as tofacitinib, in vitiligo treatment. Additionally, JAK inhibitors can yet be regarded as a promising new treatment option for vitiligo patients with concurrent autoimmune diseases.

Network pharmacology and molecular docking to explore the mechanism of a clinical proved recipe for external use of clearing heat and removing dampness in the treatment of immune-related cutaneous adverse events

Immune-related cutaneous adverse events (ircAEs) will undermine the patients' quality of lives, and interrupt the antitumor therapy. A clinical proved recipe for external use of clearing heat and removing dampness (Qing-Re-Li-Shi Formula, hereinafter referred to as "QRLSF") is beneficial to the treatment of ircAEs in clinical practice. Our study will elucidate the mechanism of QRLSF against ircAEs based on network pharmacology and molecular docking. The active components and corresponding targets of QRLSF were collected through traditional Chinese medicine systems pharmacology database. GeneCards, online Mendelian inheritance in man, and pharmacogenomics knowledgebase were used to screen the targets of ircAEs. The intersecting targets between drug and disease were acquired by venn analysis. Cytoscape software was employed to construct "components-targets" network. Search tool for the retrieval of interacting genes/proteins database was applied to establish the protein-protein interaction network and then its core targets were identified. Gene ontology and Kyoto encyclopedia of genes and genomes analysis was performed to predict the mechanism. The molecular docking verification of key targets and related phytomolecules was accomplished by AutoDock Vina software. Thirty-nine intersecting targets related to QRLSF against ircAEs were recognized. The analysis of network clarified 5 core targets (STAT3, RELA, TNF, TP53, and NFKBIA) and 4 key components (quercetin, apigenin, luteolin, and ursolic acid). The activity of QRLSF against ircAEs could be attributed to the regulation of multiple biological effects via multi-pathways (PI3K-Akt pathway, cytokine-cytokine receptor interaction, JAK-STAT pathway, chemokine pathway, Th17 cell differentiation, IL-17 pathway, TNF pathway, and Toll-like receptor pathway). The binding activities were estimated as good level by molecular docking. These discoveries disclosed the multi-component, multi-target, and multi-pathway characteristics of QRLSF against ircAEs, providing a new strategy for such medical problem.

Non-biologic immunosuppressive drugs for inflammatory and autoimmune skin diseases

Non-biologic immunosuppressive drugs, such as azathioprine, dapsone or methotrexate are fundamental treatment options for a wide range of autoimmune and chronic inflammatory skin diseases. Some of these drugs were initially used for malignancies (e.g., azathioprine or methotrexate) or infectious diseases (e.g., hydroxychloroquine or dapsone) but are nowadays mostly used for their immunosuppressive/immunomodulating action. Although dermatologists have years of clinical experience with these drugs, some of the mechanisms of action are not fully understood and are the subject of research. Although these drugs are commonly used, lack of experience or knowledge regarding their safety profiles and management leads to skepticism among physicians. Here, we summarize the mechanism of action and detailed management of adverse effects of the most commonly used immunosuppressive drugs for skin diseases. Furthermore, we discuss the management of these drugs during pregnancy and breastfeeding, as well as their interaction and handling during vaccination.

Efficacy and safety of the oral Janus kinase 1 inhibitor povorcitinib (INCB054707) in patients with hidradenitis suppurativa in a phase 2, randomized, double-blind, dose-ranging, placebo-controlled study

BACKGROUND

Janus kinase 1 inhibition may alleviate hidradenitis suppurativa (HS)-associated inflammation and improve symptoms.

OBJECTIVE

To assess efficacy and safety of povorcitinib (selective oral Janus kinase 1 inhibitor) in HS.

METHODS

This placebo-controlled phase 2 study randomized patients with HS 1:1:1:1 to receive povorcitinib 15, 45, or 75 mg or placebo for 16 weeks. Primary and key secondary end points were mean change from baseline in abscess and inflammatory nodule count and percentage of patients achieving HS Clinical Response at week 16.

RESULTS

Of 209 patients randomized (15 mg, n = 52; 45 mg, n = 52; 75 mg, n = 53; placebo, n = 52), 83.3% completed the 16-week treatment. At week 16, povorcitinib significantly reduced abscess and inflammatory nodule count from baseline (least squares mean [SE] change: 15 mg, -5.2 [0.9], P = .0277; 45 mg, -6.9 [0.9], P = .0006; 75 mg, -6.3 [0.9], P = .0021) versus placebo (-2.5 [0.9]). More povorcitinib-treated patients achieved HS Clinical Response at week 16 (15 mg, 48.1%, P = .0445; 45 mg, 44.2%, P = .0998; 75 mg, 45.3%, P = .0829) versus placebo (28.8%). A total of 60.0% and 65.4% of povorcitinib- and placebo-treated patients had adverse events.

LIMITATIONS

Baseline lesion counts were mildly imbalanced between groups.

CONCLUSION

Povorcitinib demonstrated efficacy in HS, with no evidence of increased incidence of adverse events among doses.

Short-Term Cardiovascular Complications in Dermatology Patients Receiving JAK-STAT Inhibitors: A Meta-Analysis of Randomized Clinical Trials

Importance

Evolving evidence suggests that patients receiving Janus kinase-signal transducer and activator of transcription inhibitors (JAK-STATi) may be at higher risk of major adverse cardiovascular events (MACE) and venous thromboembolism (VTE). Most existing literature has focused on indications that may confer a higher MACE and VTE risk than that among patients with isolated dermatological indications.

Objective

To evaluate risk of MACE, VTE, serious adverse events (SAEs), and tolerability of systemic JAK-STATi compared with placebo, in those with a dermatologic indication.

Data Sources

A systematic review of the literature was carried out to June 2023, using databases Embase, MEDLINE, SCOPUS, Cochrane Library of Registered Trials, and registered Clinical Trials. The analysis was reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines. The analysis itself took place in June 2023.

Study Selection

Placebo-controlled randomized clinical trials that compared systemic JAK-STATi with placebo, and investigated the safety in patients with alopecia areata, psoriasis, vitiligo, atopic dermatitis, lichen planus or hidradenitis suppurativa.

Data Extraction and Synthesis

Study selection and data extraction by 2 authors working independently using a standardized template. Crude numbers for MACE, VTE, SAEs, and study discontinuation due to treatment emergent adverse events (TEAEs) were pooled and underwent meta-analysis.

Main Outcomes and Measures

Incidence of MACE, VTE, SAE, and study discontinuation due to TEAEs. Analysis of these values against person exposure years to determine the incidence rate (IR). Risk ratios (RRs) compared incidence rates among treatment and placebo comparator arms.

Results

Forty-five randomized clinical trials were eligible for inclusion, with 12 996 patients receiving active JAK-STATi therapy and 4925 allocated to placebo treatment. Meta-analysis found no significant increase in MACE (I2 = 0.00%; RR, 0.47; 95% CI, 0.28-0.80) or VTE (I2 = 0.00%; RR, 0.46; 95% CI, 0.26-0.80) between placebo and JAK-STATi comparator arms. There was also no significant difference in SAEs (I2 = 12.38%; RR, 0.92; 95% CI, 0.72-1.20) and discontinuations between JAK-STATi and placebo (I2 = 23.55%; RR, 0.94; 95% CI, 0.76-1.19).

Conclusions and Relevance

This meta-analysis did not identify a significant increase in the risk of MACE and VTE in dermatology patients receiving JAK-STATi for median duration of 16 weeks. The results of this review suggest there is insufficient evidence that JAK-STATi confer an increased risk of cardiovascular complications in dermatological patients, especially when used for short time frames.

Riboflavin alleviates fluoride-induced ferroptosis by IL-17A-independent system Xc-/GPX4 pathway and iron metabolism in testicular Leydig cells

Fluoride is widely found in groundwater, soil, animal and plant organisms. Excessive fluoride exposure can cause reproductive dysfunction by activating IL-17A signaling pathway. However, the adverse effects of fluoride on male reproductive system and the mechanisms remain elusive. In this study, the wild type and IL-17A knockout C57BL/6J mouse were treated with 24 mg/kg·bw·d sodium fluoride and/or 5 mg/kg·bw·d riboflavin-5'-phosphate sodium for 91 days. Results showed that fluoride caused dental fluorosis, increased the levels of ROS in testicular Leydig cells and GSSG in testicular tissue, and did not affect the iron and serum hepcidin levels in testicular tissue. Riboflavin alleviated above adverse changes, whereas IL-17A does not participate in the oxidative stress-mediated reproductive toxicity of fluoride. Based on this, TM3 cells were used to verify the injury of fluoride on Leydig cells. Results showed that fluoride increased mRNA levels of ferroptosis marker SLC3A2, VDAC3, TFRC, and SLC40A1 and decreased Nrf2 mRNA levels in TM3 cells. The ferroptosis inhibitor Lip-1 and DFO were used to further investigate the relationship between male reproductive toxicity and ferroptosis induced by fluoride. We found that the fluoride-induced decrease in cell viability, increase in xCT, TFRC, and FTH protein expression, and decrease in GPX4 protein expression, can all be rescued by Lip-1 and DFO. Similar results were also observed in the riboflavin treatment group. Moreover, riboflavin mitigated fluoride-induced increases in ROS levels and SLC3A2 protein levels. In all, our work revealed that riboflavin inhibited ferroptosis in testicular Leydig cells and improved the declined male reproductive function caused by fluoride. This study provides new perspectives for revealing new male reproductive toxicity mechanisms and mitigating fluoride toxicity damage.

Nicht-Biologika-Immunsuppressiva bei entzündlichen und autoimmunen Hautkrankheiten: Non-biologic immunosuppressive drugs for inflammatory and autoimmune skin diseases

Nicht‐Biologika‐Immunsuppressiva wie Azathioprin, Dapson oder Methotrexat sind grundlegende Behandlungsmöglichkeiten für ein breites Spektrum von Autoimmunerkrankungen und chronisch‐entzündlichen Hauterkrankungen. Einige dieser Medikamente wurden ursprünglich bei malignen Erkrankungen (zum Beispiel Azathioprin oder Methotrexat) oder Infektionskrankheiten (zum Beispiel Hydroxychloroquin oder Dapson) eingesetzt, werden aber heute hauptsächlich wegen ihrer immunsuppressiven/immunmodulierenden Wirkung verwendet. Obwohl Dermatologen über jahrelange klinische Erfahrung mit diesen Arzneimitteln verfügen, sind einige der Wirkmechanismen noch nicht vollständig geklärt und noch Gegenstand der Forschung. Obwohl diese Medikamente häufig eingesetzt werden, führen mangelnde Erfahrung oder fehlendes Wissen über ihre Sicherheitsprofile und ihr Management zu einer skeptischen Haltung bei den Ärzten. Hier fassen wir den Wirkmechanismus und das detaillierte Management der Nebenwirkungen der am häufigsten verwendeten immunsuppressiven Medikamente für Hautkrankheiten zusammen. Darüber hinaus diskutieren wir den Umgang mit diesen Medikamenten während der Schwangerschaft und Stillzeit sowie ihre Wechselwirkung und Handhabung im Zusammenhang mit Impfungen.

JAK Inhibitors in Cutaneous T-Cell Lymphoma: Friend or Foe? A Systematic Review of the Published Literature

Cutaneous T-cell lymphomas (CTCLs) are a group of lymphoid neoplasms with high relapse rates and no curative treatment other than allogeneic stem cell transplantation (allo-SCT). CTCL is significantly influenced by disruption of JAK/STAT signaling. Therefore, Janus kinase (JAK) inhibitors may be promising for CTCL treatment. This study is a systematic review aiming to investigate the role of JAK inhibitors in the treatment of CTCL, including their efficacy and safety. Out of 438 initially searched articles, we present 13 eligible ones. The overall response rate (ORR) in the treatment with JAK inhibitors in clinical trials was 11-35%, although different subtypes of CTCL showed different ORRs. Mycosis fungoides showed an ORR of 14-45%, while subcutaneous-panniculitis-like T-cell lymphoma (SPTCL) displayed an ORR ranging from 75% to 100%. Five cases were reported having a relapse/incident of CTCL after using JAK inhibitors; of these, three cases were de novo CTCLs in patients under treatment with a JAK inhibitor due to refractory arthritis, and two cases were relapsed disease after graft-versus-host disease treatment following allo-SCT. In conclusion, using JAK inhibitors for CTCL treatment seems promising with acceptable side effects, especially in patients with SPTCL. Some biomarkers, like pS6, showed an association with better responses. Caution should be taken when treating patients with an underlying autoimmune disease and prior immunosuppression.

Rapid resolution of non-segmental vitiligo in a patient treated with abrocitinib: A case report

Vitiligo is a common, autoimmune, depigmenting disorder of the skin. Janus Kinase inhibitors have emerged as promising topical and oral therapeutic options for vitiligo. There have been no reports of vitiligo being treated with oral Abrocitinib, a selective Janus Kinase 1 inhibitor approved for the treatment of moderate to severe atopic dermatitis. Here, we present a 61-year-old male with acrofacial vitiligo who had repigmentation plateau with twice daily tacrolimus 0.1% ointment, oral ginkgo biloba, and oral minipulse prednisone × 4 months; however, they had significant improvement after taking abrocitinib 100 mg per day for 2 months. He was able to transition topical tacrolimus twice weekly monotherapy for maintenance. This report shows that oral Janus Kinase inhibitors may be a useful option for the treatment of recalcitrant vitiligo. Results of ongoing randomized control trials are needed to determine the durability and safety of oral Janus Kinase inhibitors long-term.

Microarray Gene Expression Analysis of Lesional Skin in Canine Pemphigus Foliaceus

Canine pemphigus foliaceus (PF) is considered the most common autoimmune skin disease in dogs; the mechanism of PF disease development is currently poorly understood. Therefore, this study aimed to characterize the molecular mechanisms and altered biological pathways in the skin lesions of canine PF patients. Using an RNA microarray on formalin-fixed, paraffin-embedded samples, we analyzed the transcriptome of canine PF lesional skin (n = 7) compared to healthy skin (n = 5). Of the 800 genes analyzed, 420 differentially expressed genes (DEGs) (p < 0.05) were found. Of those, 338 genes were significantly upregulated, including pro-inflammatory and Th17-related genes. Cell type profiling found enhancement of several cell types, such as neutrophils, T-cells, and macrophages, in PF skin compared to healthy skin. Enrichment analyses of the upregulated DEGs resulted in 78 statistically significant process networks (FDR < 0.05), including the Janus kinase signal transducer and activator of transcription (JAK-STAT) and mitogen-activated protein kinase (MAPK) signaling. In conclusion, canine PF lesional immune signature resembles previously published changes in human pemphigus skin lesions. Further studies with canine PF lesional skin using next-generation sequencing (e.g., RNA sequencing, spatial transcriptomics, etc.) and the development of canine keratinocyte/skin explant PF models are needed to elucidate the pathogenesis of this debilitating disease.

S3 guideline Atopic dermatitis: Part 2 - Systemic treatment

The present S3 guideline was created based on the European English-language S3 guideline, with special consideration given to the medical conditions in the German-speaking region, and with additions from the previous German-language version, in accordance with the criteria of the AWMF. This second part of the guideline addresses the systemic therapy of atopic dermatitis (AD). It covers topics such as the indication for systemic therapy in children, adolescents, and adult patients with AD. Furthermore, it addresses all medications approved for AD, such as the biologics dupilumab and tralokinumab, the Janus kinase inhibitors abrocitinib, baricitinib, and upadacitinib, as well as conventional immunosuppressive therapies with systemic glucocorticosteroids and ciclosporin. Additionally, it discusses systemic off-label therapies. The first part of the guideline, published separately, includes the definition and diagnostic aspects of AD, describes topical therapy, non-drug therapy approaches, and addresses aspects related to special patient groups.

S3-Leitlinie Atopische Dermatitis: Teil 2 - Systemische Therapie: S3 guideline Atopic dermatitis: Part 2 - Systemic treatment

Die vorliegende S3‐Leitlinie wurde auf der Basis der europäischen englischsprachigen S3‐Leitlinie unter besonderer Berücksichtigung der medizinischen Gegebenheiten im deutschsprachigen Raum und mit Ergänzungen der deutschsprachigen Vorgängerversion, entsprechend den Kriterien der AWMF, erstellt. Dieser zweite Teil der Leitlinie behandelt die systemische Therapie der atopischen Dermatitis (AD). Eingegangen wird unter anderem auf die Indikationsstellung für eine Systemtherapie bei Kindern, Jugendlichen und erwachsenen Patienten mit AD. Darüber hinaus werden alle für die AD zugelassenen Medikamente wie die Biologika Dupilumab und Tralokinumab, die Januskinase‐Inhibitoren Abrocitinib, Baricitinib und Upadacitinib sowie die konventionellen immunsuppressiven Therapien mit systemischen Glukokortikosteroiden und Ciclosporin adressiert. Systemische Off‐Label‐Therapien werden ebenfalls behandelt. Der separat publizierte erste Teil der Leitlinie umfasst die Definition und diagnostischen Aspekte der AD, beschreibt die topische Therapie sowie nichtmedikamentöse Therapieverfahren und geht auf Aspekte bei besonderen Patientengruppen ein.

The oncogenic mechanisms of the Janus kinase-signal transducer and activator of transcription pathway in digestive tract tumors

Digestive tract tumors are heterogeneous and involve the dysregulation of multiple signaling pathways. The Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway plays a notable role in the oncogenesis of digestive tract tumors. Typically activated by pro-inflammatory cytokines, it regulates important biological processes, such as cell growth, differentiation, apoptosis, immune responses, and inflammation. The aberrant activation of this pathway manifests in different forms, including mutations in JAKs, overexpression of cytokine receptors, and sustained STAT activation, and contributes to promoting the malignant characteristics of cancer cells, including uncontrolled proliferation, resistance to apoptosis, enhanced invasion and metastasis, angiogenesis, acquisition of stem-like properties, and drug resistance. Numerous studies have shown that aberrant activation of the JAK-STAT pathway is closely related to the development and progression of digestive tract tumors, contributing to tumor survival, angiogenesis, changes in the tumor microenvironment, and even immune escape processes. In addition, this signaling pathway also affects the sensitivity of digestive tract tumors to chemotherapy and targeted therapy. Therefore, it is crucial to comprehensively understand the oncogenic mechanisms underlying the JAK-STAT pathway in order to develop effective therapeutic strategies against digestive tract tumors. Currently, several JAK-STAT inhibitors are undergoing clinical and preclinical trials as potential treatments for various human diseases. However, further investigation is required to determine the role of this pathway, as well as the effectiveness and safety of its inhibitors, especially in the context of digestive tract tumors. In this review, we provide an overview of the structure, classic activation, and negative regulation of the JAK-STAT pathway. Furthermore, we discuss the pathogenic mechanisms of JAK-STAT signaling in different digestive tract tumors, with the aim of identifying potential novel therapeutic targets. Video Abstract.

Emerging Oral Therapies for the Treatment of Psoriasis: A Review of Pipeline Agents

The introduction of biologic agents for the treatment of psoriasis has revolutionized the current treatment landscape, targeting cytokines in the interleukin (IL)-23/IL-17 pathway and demonstrating strong efficacy and safety profiles in clinical trials. These agents however are costly, are associated with a risk of immunogenicity, and require administration by intravenous or subcutaneous injection, limiting their use among patients. Oral therapies, specifically small molecule and microbiome therapeutics, have the potential to be more convenient and cost-effective agents for patients and have been a focus of development in recent years, with few targeted oral medications available for the disease. In this manuscript, we review pipeline oral therapies for psoriasis identified through a search of ClinicalTrials.gov (30 June 2022-1 October 2023). Available preclinical and clinical trial data on each therapeutic agent are discussed. Small molecules under development include tumor necrosis factor inhibitors, IL-23 inhibitors, IL-17 inhibitors, phosphodiesterase-4 inhibitors, Janus kinase inhibitors, A3 adenosine receptor agonists, and sphingosine-1-phosphate receptor 1 agonists, several of which are entering phase III trials. Oral microbials have also demonstrated success in early phase studies. As new oral therapies emerge for the treatment of psoriasis, real-world data and comparative trials are needed to better inform their use among patients.

Selectivity, efficacy and safety of JAKinibs: new evidence for a still evolving story

Fundamental insight gained over the last decades led to the discovery of cytokines as pivotal drivers of inflammatory diseases such as rheumatoid arthritis, psoriasis/psoriasis arthritis, inflammatory bowel diseases, atopic dermatitis and spondylarthritis. A deeper understanding of the pro-inflammatory and anti-inflammatory effects of various cytokines has prompted new cytokine-targeting therapies, which revolutionised the treatment options in the last years for patients with inflammatory disorders. Disease-associated immune responses typically involve a complex interplay of multiple cytokines. Therefore, blockade of one single cytokine does not necessarily lead to a persistent remission in all patients with inflammatory disorders and fostered new therapeutic strategies targeting intracellular pathways shared by multiple cytokines. By inhibiting JAK-STAT signalling pathways common to families of cytokines, JAK-inhibitors (JAKinibs) have created a new paradigm for the treatment of inflammatory diseases. Multiple agents have been approved for various disorders and more are being investigated for several new indications. Second-generation selective JAKinibs have been devised with the aim to achieve an increased selectivity and a possible reduced risk of side effects. In the current review, we will summarise the current body of evidence of pan versus selective JAKinibs and the most recent insights on new side effects and indications, including COVID-19.

Topical Delivery of Tofacitinib in Dermatology: The Promise of a Novel Therapeutic Class Using Biodegradable Dendritic Polyglycerol Sulfates

Inflammatory skin diseases, such as psoriasis, atopic dermatitis, and alopecia areata, occur when the regulatory tolerance of the innate immune system is disrupted, resulting in the activation of the Janus kinase-signal transducer and activator of transcription (JAK-STAT) inflammatory signaling pathway by interleukin 6 (IL-6) and other key inflammatory cytokines. JAK inhibitors, such as tofacitinib, bind to these enzymes which are coupled to receptors on cell surfaces and block the transcription of inflammatory cytokine-induced genes. The first topical applications are being marketed, yet insufficient effects regarding indications, such as alopecia areata, suggest that improved delivery technologies could help increase the efficacy. In this study, we used sulfated dendritic polyglycerol with caprolactone segments integrated in its backbone (dPGS-PCL), with a molecular weight of 54 kDa, as a degradable carrier to load and solubilize the hydrophobic drug tofacitinib (TFB). TFB loaded in dPGS-PCL (dPGS-PCL@TFB), at a 11 w/w% loading capacity in aqueous solution, showed in an ex-vivo human skin model better penetration than free TFB in a 30:70 (v/v) ethanol/water mixture. We also investigated the anti-inflammatory efficacy of dPGS-PCL@TFB (0.5 w/w%), dPGS-PCL, and free TFB in the water/ethanol mixture by measuring their effects on IL-6 and IL-8 release, and STAT3 and STAT5 activation in ex vivo skin models of simulated inflamed human skin. Our results suggest that dPGS-PCL@TFB reduces the activation of STAT3 and STAT5 by increasing the penetration of the tofacitinib. However, no statistically significant differences with respect to the inhibition of IL-6 and IL-8 were observed in this short incubation time.

Tofacitinib in dermatology: a potential opportunity for topical applicability through novel drug-delivery systems

Tofacitinib is a first-generation JAK inhibitor approved by the US FDA for treating rheumatoid arthritis. It exhibits a broad-spectrum inhibitory effect with abilities to block JAK-STAT signalling. The primary objective of this review is to obtain knowledge about cutting-edge methods for effectively treating a variety of skin problems by including tofacitinib into formulations that are based on nanocarriers. The review also highlights clinical trials and offers an update on published clinical patents. Nanocarriers provide superior performance compared to conventional treatments in terms of efficacy, stability, drug bioavailability, target selectivity and sustained drug release. Current review has the potential to make significant contributions to the ongoing discussion involving dermatological treatments and the prospective impact of nanotechnology on transforming healthcare within this field.

Identification and Biological Evaluation of a Potent and Selective JAK1 Inhibitor for the Treatment of Pulmonary Fibrosis

Janus kinase 1 (JAK1) plays a pivotal role in regulating inflammation and fibrosis via the JAK/STAT signaling pathway, making it a promising target for associated diseases. In this study, we explored the modification of an N-methyl 1H-pyrrolo[2,3-b]pyridine-5-carboxylate core, leading to the identification of 4-(((2S,4S)-1-(4-trifluoromethyl)-2-methylpiperidin-4-yl)amino)-N-methyl-1H-pyrrolo[2,3-b]pyridine-5-carboxamide (36b) as a highly potent and selective JAK1 inhibitor. Compound 36b exhibited an impressive IC50 value of 0.044 nM for JAK1 and demonstrated remarkable selectivity of 382-fold, 210-fold, and 1325-fold specificity over JAK2, JAK3, and TYK2, respectively. The kinase panel assays further confirmed its specificity, and cell-based experiments established its efficacy in inhibiting JAK1-STAT phosphorylation in human L-132 or SK-MES-1 cells. Pharmacokinetic studies revealed that compound 36b boasts an oral bioavailability exceeding 36%. In a bleomycin-induced fibrosis mouse model, compound 36b significantly reduced STAT3 phosphorylation, resulting in improvement in body weight and reduced collagen deposition, all achieved without significant side effects.