Ruxolitinib cream for treatment of vitiligo: a randomised, controlled, phase 2 trial

Computer-aided assessment of repigmentation rates in vitiligo patients: Implications for treatment efficacy - a retrospective study

Precise evaluation of repigmentation in vitiligo patients is crucial for monitoring treatment efficacy and enhancing patient satisfaction. This study aimed to develop a computer-aided system for assessing repigmentation rates in vitiligo patients, providing valuable insights for clinical practice. A retrospective study was conducted at the Dermatology Department of Shenzhen People's Hospital between June 2019 and November 2022. Pre- and post-treatment images of vitiligo lesions under Wood's lamp were collected, involving 833 participants stratified by sex, age, and pigmentation patterns. Our results demonstrated that the 'marginal' pigmentation pattern exhibited a higher repigmentation rate of 72% compared to the 'central non-follicular' pattern at 45%. Males had a slightly higher average repigmentation rate of 0.37 in comparison to females at 0.33. Among age groups, individuals aged 0-20 years showed the highest average repigmentation rate at 0.41, while the oldest age group (61-80 years) displayed the lowest rate at 0.25. Analysis of multiple visits identified the 'marginal' pattern as the most prevalent (60%), with a mean repigmentation rate of 40%. This study introduced a computational system for evaluating vitiligo repigmentation rates, enhancing our comprehension of patient responses, ultimately contributing to enhanced clinical care.

Patient Burden of Nonsegmental Vitiligo: A US Real-World Survey of Dermatologists and Their Patients

INTRODUCTION

Vitiligo is a chronic autoimmune disease characterized by destruction of melanocytes, leading to skin depigmentation. Vitiligo can have a high quality-of-life burden and profound impact on psychosocial well-being. The objectives of this study were to describe the self-reported patient burden among patients with nonsegmental vitiligo with ≤ 10% affected body surface area, summarize the physician-reported psychosocial and psychological impact of vitiligo on patient lives, and describe disease characteristics and treatment history, goals, and satisfaction.

METHODS

Data were drawn from the Adelphi Vitiligo Disease Specific Programme™, a real-world, cross-sectional survey with retrospective data collection of physicians and patients with vitiligo, collected in the United States between October 2021 and April 2022. Separate surveys for dermatologists and patients contained questions on clinical and demographic characteristics of patients with vitiligo and burden of vitiligo. Treatment history, goals, and satisfaction were assessed together with the impact of vitiligo on quality of life.

RESULTS

Sixty-one dermatologists provided data for 326 patients with ≤ 10% affected body surface area (adults, n = 221; adolescents, n = 105); 90 of those patients also responded to the survey. The most common treatments were topical corticosteroids, topical calcineurin inhibitors, and narrow-band ultraviolet-B phototherapy, with the main treatment goal being repigmentation. Physician-reported treatment satisfaction was 56%; 25% of patients reported frustration with treatment options. Physicians reported impact of vitiligo on everyday life in 46% of patients. Patients reported 12.7% overall work impairment; mean scores for Hospital Anxiety and Depression Scale anxiety and depression domains were 3.5 and 2.2, respectively, and mean Vitiligo-specific Quality of Life index score was 26.9. Patients with facial involvement experienced higher burden than those without.

CONCLUSION

A high patient burden was reported by dermatologists and their patients with vitiligo who had ≤ 10% affected body surface area, including psychosocial and psychological consequences. These findings highlight an unmet need in the treatment of vitiligo.

From mice to men: An assessment of preclinical model systems for the study of vitiligo

Vitiligo is an autoimmune skin disease of multiple etiology, for which there is no complete cure. This chronic depigmentation is characterized by epidermal melanocyte loss, and causes disfigurement and significant psychosocial distress. Mouse models have been extensively employed to further our understanding of complex disease mechanisms in vitiligo, as well as to provide a preclinical platform for clinical interventional research on potential treatment strategies in humans. The current mouse models can be categorized into three groups: spontaneous mouse models, induced mouse models, and transgenic mice. Despite their limitations, these models allow us to understand the pathology processes of vitiligo at molecule, cell, tissue, organ, and system levels, and have been used to test prospective drugs. In this review, we comprehensively evaluate existing murine systems of vitiligo and elucidate their respective characteristics, aiming to offer a panorama for researchers to select the appropriate mouse models for their study.

Ruxolitinib Cream 1.5%: A Review in Non-Segmental Vitiligo

Topical ruxolitinib 1.5% cream (Opzelura®), a Janus kinase (JAK) inhibitor, is the first treatment to be approved in several countries for use in patients aged ≥ 12 years with non-segmental vitiligo. In the identical phase III TRuE-V1 and TRuE-V2 trials, significantly more ruxolitinib cream recipients were able to achieve statistically significant and clinically meaningful facial and total body repigmentation, as well as reductions in vitiligo noticeability, compared with vehicle recipients. Efficacy was sustained in longer-term analyses to week 104 of treatment. Ruxolitinib 1.5% cream was generally tolerable in these trials; the most common treatment-related adverse events were acne, pruritus and exfoliation, all at the application site. As with orally administered JAK inhibitors, topical ruxolitinib carries boxed warnings in the USA for serious infections, mortality, malignancy, major adverse cardiovascular events (MACE) and thrombosis, although the incidences were low with topical application. Thus, topical ruxolitinib 1.5% cream is an effective and generally tolerable treatment option for patients aged ≥ 12 years with non-segmental vitiligo.

Proteomics data in vitiligo: a scoping review

An unbiased screening of which proteins are deregulated in vitiligo using proteomics can offer an enormous value. It could not only reveal robust biomarkers for detecting disease activity but can also identify which patients are most likely to respond to treatments. We performed a scoping review searching for all articles using proteomics in vitiligo. Eight manuscripts could be identified. Unfortunately, very limited overlap was found in the differentially expressed proteins between studies (15 out of 272; 5,51%) with variable degrees of the type of proteins and a substantial variety in the prevalence of acute phase proteins (range: 6-65%). Proteomics research has therefore brought little corroborating evidence on which proteins are differentially regulated between vitiligo patients and healthy controls or between active and stable vitiligo patients. While a limited patient size is an obvious weakness for several studies, an incomplete description of patient characteristics is an unfortunate and avoidable shortcoming. Additionally, the variations in the used methodology and analyses may further contribute to the overall observed variability. Nonetheless, more recent studies investigating the response to treatment seem to be more robust, as more differentially expressed proteins that have previously been confirmed to be involved in vitiligo were found. The further inclusion of proteomics analyses in clinical trials is recommended to increase insights into the pathogenic mechanisms in vitiligo and identify reliable biomarkers or promising drug targets. A harmonization in the study design, reporting and proteomics methodology could vastly improve the value of vitiligo proteomics research.

Janus kinase inhibitors and the changing landscape of vitiligo management: a scoping review

Vitiligo is a chronic skin condition caused by an autoimmune response that results in the progressive loss of melanocytes and recent studies have suggested that Janus kinase inhibitors (JAKi) are emerging as a promising new treatment modality. Therefore, to assess and understand the extent of knowledge in the emerging field of JAKi use in vitiligo, a scoping review of the literature was undertaken. The reviewed articles explored a wide variety of JAKi administered either orally or topically for vitiligo. There were no injectable JAKi studied. Tofacitinib was the most commonly studied oral JAKi in 16 of the 35 studies selected for review, followed by baricitinib (n = 3), and one study each with ritlecitinib, ruxolitinib, and upadacitinib. Ruxolitinib (n = 6) and tofacitinib (n = 6) were the most often studied topical JAKi, followed by delgocitinib (n = 1). Potential benefits may vary between JAKi based on their receptor selectivity profile and coexistent autoimmune diseases. A topical JAKi would be advantageous in limited body area involvement and in adolescents. Concurrent use of JAKi with phototherapy or sun exposure appears beneficial. Most studies permitted the use of other topical agents. Acne-related events, though frequent yet mild, were reported with both oral and topical JAKi. Nasopharyngitis, upper respiratory tract infections, and headaches were the most common adverse effects seen in the larger trials with JAKi. No serious or clinically meaningful hematology or thromboembolic events were detected. Treatment of vitiligo with oral or topical JAKi seems to be promising and the growing evidence shows a favorable risk-benefit profile.

Comparative efficacy and safety of JAK inhibitors in the treatment of moderate-to-severe alopecia areata: a systematic review and network meta-analysis

We performed a Bayesian network meta-analysis to indirectly compare the relative efficacy and safety of the latest JAK inhibitors for moderate-to-severe alopecia areata (AA). 13 trials totaling 3,613 patients were included. Two low-dose groups of oral formulations (ritlecitinib 10mg and ivarmacitinib 2mg) and two topical formulations (delgocitinib ointment and ruxolitinib cream) appeared to be relatively ineffective against moderate-to-severe AA. Ranking analysis suggested that brepocitinib 30mg has the best relative effect in reducing the SALT score (sucra = 0.9831), and demonstrated comparable efficacy to deuruxolitinib 12mg (sucra = 0.9245), followed by deuruxolitinib 8mg (sucra = 0.7736). Regarding the SALT50 response, brepocitinib 30mg ranked highest (sucra = 0.9567), followed by ritlecitinib 50mg (sucra = 0.8689) and deuruxolitinib 12mg (sucra = 0.7690). For achieving the SALT75 response, deuruxolitinib 12mg had the highest probability (sucra = 0.9761), followed by deuruxolitinib 8mg (sucra = 0.8678) and brepocitinib 30mg (sucra = 0.8448). Deuruxolitinib 12mg might be the most effective therapy for patients with severe AA (sucra = 0.9395), followed by ritlecitinib 50mg (sucra = 0.8753) and deuruxolitinib 8mg (sucra = 0.8070). Deuruxolitinib 12mg/8mg demonstrated notable efficacy for moderate-to-severe AA, and is expected to be a new treatment option for AA. It was worth noting that deuruxolitinib exhibit a greater likelihood of causing adverse events in comparison to other JAK inhibitors. Ritlecitinib 50mg seemed to exhibit fewer adverse effects in the high-dose groups of oral JAK inhibitors and might be an optimal choice to balance safety and efficacy. The majority of JAK inhibitors exhibited acceptable short-term safety profiles. To enhance the applicability and accuracy of our research, further head-to-head trials with longer follow-up periods are needed. Systematic Review Registration: identifier [CRD42022368012].

Expert Recommendations on Use of Topical Therapeutics for Vitiligo in Pediatric, Adolescent, and Young Adult Patients

Importance

Evidence-based recommendations for the treatment of vitiligo in pediatric, adolescent, and young adult patients in the US are needed.

Objective

To develop evidence- and consensus-based expert recommendations on the diagnosis and treatment of vitiligo in young patients.

Evidence Review

A process was developed to produce consensus recommendations addressing questions regarding pediatric vitiligo. A librarian-conducted literature review was performed using articles that met the inclusion criteria: published in English, containing primary data (including meta-analysis) and pediatric-specific data, and analysis of 6 or more patients. Included articles were graded by the Strength of Recommendation Taxonomy criteria and Oxford Centre for Evidence-based Medicine's Levels of Evidence and Grades of Recommendation. Research questions were reviewed on May 9, 2022, through a video conference. One month after the conference, participants participated in an online survey documenting their level of agreement with the generated statements, using a 5-point Likert scale.

Findings

Articles on topical corticosteroids and/or topical calcineurin inhibitors (n = 50), topical Janus kinase inhibitors (n = 5), pseudocatalase (n = 2), and microdermabrasion (n = 2) met inclusion criteria. Forty-two recommendations were made on the diagnosis of vitiligo and optimal topical therapeutics, with 33 recommendations obtaining a 70% or greater composite agreement and strong agreement. Topical calcineurin inhibitors twice daily, topical corticosteroids with time limitation due to atrophy risk, and topical ruxolitinib, 1.5%, cream-used off-label for patients younger than 12 years and limited to nonsegmental vitiligo-were identified as evidence-based first-line therapies in the management of pediatric and adolescent patients, with specific guidance on age-based data, minimum therapeutic trial of 6 months or greater, prolonged therapy to prevent recurrence, and the positive benefit of coordinated use of UV therapeutic sources.

Conclusions and Relevance

Evidence supports the use of topical calcineurin inhibitors, topical corticosteroids, and topical Janus kinase inhibitors as effective therapeutics for vitiligo in pediatric, adolescent, and young adult patients, with specific decisions on choice of agent based on factors such as site location, body surface area, and age.

The IFN-γ-CXCL9/CXCL10-CXCR3 axis in vitiligo: Pathological mechanism and treatment

Vitiligo is a disease featuring distinct white patches that result from melanocyte destruction. The overall pathogenesis of vitiligo remains to be elucidated. Nevertheless, considerable research indicates that adaptive immune activation plays a key role in this process. Specifically, the interferon-gamma (IFN-γ), C-X-C motif chemokine ligands (CXCL9/10), and C-X-C motif chemokine receptor (CXCR3) signaling axis, collectively referred to as IFN-γ-CXCL9/10-CXCR3 or ICC axis, has emerged as a key mediator responsible for the recruitment of autoimmune CXCR3+ CD8+ T cells. These cells serve as executioners of melanocytes by promoting their detachment and apoptosis. Moreover, IFN-γ is generated by activated T cells to create a positive feedback loop, exacerbating the autoimmune response. This review not only delves into the mechanistic insights of the ICC axis but also explores the significant immunological effects of associated cytokines and their receptors. Additionally, the review provides a thorough comparison of existing and emerging treatment options that target the ICC axis for managing vitiligo. This review aims to foster further advancements in basic research within related fields and facilitate a deeper understanding of alternative treatment strategies targeting different elements of the axis.

Real-World Use of Ruxolitinib Cream: Safety Analysis at 1 Year

BACKGROUND

Ruxolitinib cream is the first topical Janus kinase (JAK) inhibitor approved in the United States (US) for the treatment of mild to moderate atopic dermatitis and nonsegmental vitiligo. A postmarketing study with oral tofacitinib, approved for rheumatoid arthritis, triggered class warnings for JAK inhibitors, including risk of serious infections, mortality, malignancy, major adverse cardiovascular events, and thrombosis. Because ruxolitinib cream is indicated for inflammatory conditions, it is subject to the same warnings as oral JAK inhibitors in the US. Here, nearly 14,000 patient-years of postmarketing safety data from the first year following market approval of ruxolitinib cream were reviewed.

METHODS

The Incyte global safety database (21 September 2021-20 September 2022) and US FDA Adverse Event Reporting System (as of 30 September 2022) were queried for adverse event (AE) reports received for ruxolitinib cream.

RESULTS

The search identified 294 postmarketing individual case safety reports containing 589 events, including four serious AEs and no fatal AEs. AEs (i.e., any unfavorable sign, symptom, or disease) representing >2% of all events included application site pain (n = 16), atopic dermatitis (n = 15), skin irritation (n = 15), scratch (n = 14), and condition aggravated (n = 13). The four serious AEs were skin cancer (n = 2), pericarditis, and thrombocytopenia (both n = 1), none of which had sufficient information to assess possible relatedness to ruxolitinib cream. Serious AEs associated with the class warnings for JAK inhibitors were not reported.

CONCLUSIONS

Postmarketing safety data from the year following approval suggest ruxolitinib cream is generally well tolerated, without significant systemic AEs, and with a low incidence of application site reactions.

Vitamin D supplementation can enhance therapeutic effects of excimer laser in patients with vitiligo

PURPOSE

Vitiligo is a disease of acquired depigmentation characterized by the destruction of melanocytes. A theoretical association between low level of 25-hydroxyvitamin D [25(OH)D] and vitiligo has been previously suggested. The objective of this study was to determine the efficacy of intramuscular injection of cholecalciferol with excimer laser compared with the excimer laser alone for vitiligo treatment.

METHODS

This study included 26 patients diagnosed with non-segmental vitiligo and low serum 25(OH)D levels (<20 ng/mL). The participants were randomly divided into two groups through randomization. The treatment using a 308-nm excimer laser was administered to both groups, and the study group additionally received cholecalciferol injection.

RESULTS

The Vitiligo Area Scoring Index (VASI) scores showed an 83.6% improvement over the initial score in the study group, whereas the control group showed a 54.7% improvement after 6 months of treatment. After 6 months of treatment, the study group showed a significantly higher proportion of patients who achieved VASI50 and VASI75 compared with the control group.

CONCLUSION

Intramuscular injection of cholecalciferol can be a supplemental option for the treatment of vitiligo patients with vitamin D deficiency with excimer laser therapy.

JAK inhibitors for the treatment of vitiligo

Vitiligo is an autoimmune disease involving melanocyte-targeting T cells initiated by environmental and genetic factors. Steroids and tacrolimus have been used as topical treatments. Recently, novel topical agents targeting Janus kinase (JAK), a family of tyrosine kinases that regulates cytokine signaling, have emerged. Ruxolitinib is the first approved in vitiligo therapy. Furthermore, ritlecitinib is currently under clinical trials for oral treatment of active vitiligo. In this review, we discuss the possibility of topical JAK inhibitors as promising options for the treatment of vitiligo with regard to their mechanism of action, efficacy and safety.

Bridging Molecular Mechanism and Clinical Practice in Vitiligo Treatment: An Updated Review

BACKGROUND

Treatment of vitiligo seeks to achieve three goals: cessation of disease progression, regeneration of pigmentation, and prevention of recurrence.

SUMMARY

Number of nonsurgical interventions are available that suppress the autoimmune response and regenerate the melanocytes from the reservoir: phototherapy including psoralen and ultraviolet A, narrowband ultraviolet B, and 308-nm excimer and 311-nm Titanium:Sapphire lasers; topical agents including topical calcineurin inhibitors, topical corticosteroids, and topical 5-fluorouracil; and systemic agents including corticosteorids, mycophenolate mofetil, cyclosporine, methotrexate, minocycline, afamelanotide, and antioxidants. In recent years, a great advance has been made in the understanding of pathogenesis of vitiligo, and JAK inhibitors are being investigated as a new treatment. Minimally invasive procedures such as fractional lasers or microneedling can help achieve the optimal treatment outcome when used properly.

KEY MESSAGES

Our review describes various treatment modalities for vitiligo based on their molecular mechanism of action. Bridging the gap between molecular mechanisms and therapeutic options would be a valuable reference for physicians in clinical practice.

Evaluation of Facial Vitiligo Severity with a Mixed Clinical and Artificial Intelligence Approach

Vitiligo is the most common depigmenting skin disorder. Given the ongoing development of new targeted therapies, it has become important to evaluate adequately the surface area involved. Assessment of vitiligo scores can be time consuming, with variations between investigators. Therefore, the aim of this study was to build an artificial intelligence system capable of assessing facial vitiligo severity. One hundred pictures of faces of patients with vitiligo were used to train and validate the artificial intelligence model. Sixty-nine additional pictures of facial vitiligo were then used as a final dataset. Three expert physicians scored the facial vitiligo on the same 69 pictures. Inter and intrarater performances were evaluated by comparing the scores between raters and artificial intelligence. Algorithm assessment achieved an accuracy of 93%. Overall, the scores reached a good agreement between vitiligo raters and the artificial intelligence model. Results demonstrate the potential of the model. It provides an objective evaluation of facial vitiligo and could become a complementary/alternative tool to human assessment in clinical practice and/or clinical research.

The role of aryl hydrocarbon receptor in vitiligo: a review

Vitiligo is an acquired autoimmune dermatosis characterized by patchy skin depigmentation, causing significant psychological distress to the patients. Genetic susceptibility, environmental triggers, oxidative stress, and autoimmunity contribute to melanocyte destruction in vitiligo. Due to the diversity and complexity of pathogenesis, the combination of inhibiting melanocyte destruction and stimulating melanogenesis gives the best results in treating vitiligo. The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that can regulate the expression of various downstream genes and play roles in cell differentiation, immune response, and physiological homeostasis maintenance. Recent studies suggested that AhR signaling pathway was downregulated in vitiligo. Activation of AhR pathway helps to activate antioxidant pathways, inhibit abnormal immunity response, and upregulate the melanogenesis gene, thereby protecting melanocytes from oxidative stress damage, controlling disease progression, and promoting lesion repigmentation. Here, we review the relevant literature and summarize the possible roles of the AhR signaling pathway in vitiligo pathogenesis and treatment, to further understand the links between the AhR and vitiligo, and provide new potential therapeutic strategies.

Sexual dimorphism in melanocyte stem cell behavior reveals combinational therapeutic strategies for cutaneous repigmentation

Vitiligo is an autoimmune skin disease caused by cutaneous melanocyte loss. Although phototherapy and T cell suppression therapy have been widely used to induce epidermal re-pigmentation, full pigmentation recovery is rarely achieved due to our poor understanding of the cellular and molecular mechanisms governing this process. Here, we identify unique melanocyte stem cell (McSC) epidermal migration rates between male and female mice, which is due to sexually dimorphic cutaneous inflammatory responses generated by ultra-violet B exposure. Using genetically engineered mouse models, and unbiased bulk and single-cell mRNA sequencing approaches, we determine that manipulating the inflammatory response through cyclooxygenase and its downstream prostaglandin product regulates McSC proliferation and epidermal migration in response to UVB exposure. Furthermore, we demonstrate that a combinational therapy that manipulates both macrophages and T cells (or innate and adaptive immunity) significantly promotes epidermal melanocyte re-population. With these findings, we propose a novel therapeutic strategy for repigmentation in patients with depigmentation conditions such as vitiligo.

Janus-kinase inhibitors in dermatology: A review of their use in psoriasis, vitiligo, systemic lupus erythematosus, hidradenitis suppurativa, dermatomyositis, lichen planus, lichen planopilaris, sarcoidosis and graft-versus-host disease

Recent studies on molecular pathways have elucidated novel therapeutic approaches in inflammatory and autoimmune skin disorders. Specifically, the dysregulation of the Janus kinase signal transducer and activator of transcription (JAK-STAT) cascade plays a central role in the pathogenesis of many skin conditions. JAK inhibitors, with their ability to selectively target immune responses, are potential treatment options. Using the National Library of Medicine, we provide a comprehensive review of the use of United States Food and Drug Administration (FDA)-approved and emerging JAK or tyrosine kinase 2 (TYK2) inhibitors in a wide range of dermatologic conditions, including psoriasis, vitiligo, systemic lupus erythematosus, hidradenitis suppurativa, dermatomyositis, lichen planus, lichen planopilaris, sarcoidosis and graft-versus-host disease. In patients with psoriasis, oral deucravacitinib (TYK2 inhibitor) has been approved as a once-daily therapy with demonstrated superiority and efficacy over apremilast and placebo and tolerable safety profiles. In patients with vitiligo, topical ruxolitinib (JAK1 inhibitor) is approved as a twice-daily treatment for repigmentation. The efficacy of several other JAK inhibitors has also been demonstrated in several clinical trials and case studies for systemic lupus erythematosus, hidradenitis suppurativa, dermatomyositis, lichen planus, lichen planopilaris, sarcoidosis and graft-versus-host disease. Further investigations with long-term clinical trials are necessary to confirm their utility in treatment and safety for these diseases.

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.

Management of the refractory vitiligo patient: current therapeutic strategies and future options

Vitiligo is an autoimmune disease that leads to disfiguring depigmented lesions of skin and mucosa. Although effective treatments are available for vitiligo, there are still some patients with poor responses to conventional treatment. Refractory vitiligo lesions are mostly located on exposed sites such as acral sites and lips, leading to significant life stress. Understanding the causes of refractory vitiligo and developing targeted treatments are essential to enhance vitiligo outcomes. In this review, we summarized recent treatment approaches and some potential methods for refractory vitiligo. Janus kinase inhibitors have shown efficacy in refractory vitiligo. A variety of surgical interventions and fractional carbon dioxide laser have been widely applied to combination therapies. Furthermore, melanocyte regeneration and activation therapies are potentially effective strategies. Patients with refractory vitiligo should be referred to psychological monitoring and interventions to reduce the potential pathogenic effects of chronic stress. Finally, methods for depigmentation and camouflage may be beneficial in achieving uniform skin color and improved quality of life. Our ultimate focus is to provide alternative options for refractory vitiligo and to bring inspiration to future research.

Vitiligo: Pathogenesis and New and Emerging Treatments

Vitiligo is a complex disease with a multifactorial nature and a high impact on the quality of life of patients. Although there are multiple therapeutic alternatives, there is currently no fully effective treatment for this disease. In the current era, multiple drugs are being developed for the treatment of autoimmune diseases. This review assesses the available evidence on the pathogenesis of vitiligo, and a comprehensive review of treatments available for vitiligo now and in the near future is provided. This qualitative analysis spans 116 articles. We reviewed the mechanism of action, efficacy and safety data of phototherapy, afamelanotide, cyclosporine, phosphodiesterase 4 inhibitors, trichloroacetic acid, basic fibroblast growth factor, tumor necrosis factor (TNF) inhibitors, secukinumab, pseudocatalase and janus kinase (JAK) inhibitors. At the moment, there is no clearly outstanding option or fully satisfactory treatment for vitiligo, so it is necessary to keep up the development of new drugs as well as the publication of long-term effectiveness and safety data for existing treatments.

Janus Kinase Inhibitors and Adverse Events of Acne: A Systematic Review and Meta-Analysis

Importance

Janus kinase (JAK) inhibitors are increasingly used across a range of dermatologic conditions. Adverse events of acne have been noted in some studies in clinical practice, but the scope of this outcome across JAK inhibitors has not been established.

Objective

To systematically analyze all published phase 2 and 3 placebo-controlled randomized clinical trials (RCTs) of JAK inhibitors for the risk of acne as an adverse effect of these medications.

Data Sources

Comprehensive search of Ovid MEDLINE and PubMed databases through January 31, 2023.

Study Selection

Inclusion criteria were phase 2 and 3 placebo-controlled RCTs of JAK inhibitors published in English with reported adverse events of acne.

Data Extraction and Synthesis

Two reviewers independently reviewed and extracted information from all included studies.

Main Outcomes and Measures

The primary outcome of interest was the incidence of acne following JAK inhibitor use. A meta-analysis was conducted using random-effects models.

Results

A total of 25 unique studies (10 839 unique participants; 54% male and 46% female) were included in the final analysis. The pooled odds ratio (OR) was calculated to be 3.83 (95% CI, 2.76-5.32) with increased ORs for abrocitinib (13.47 [95% CI, 3.25-55.91]), baricitinib (4.96 [95% CI, 2.52-9.78]), upadacitinib (4.79 [95% CI, 3.61-6.37]), deucravacitinib (2.64 [95% CI, 1.44-4.86]), and deuruxolitinib (3.30 [95% CI, 1.22-8.93]). Estimated ORs were higher across studies investigating the use of JAK inhibitors for the management of dermatologic compared with nondermatologic conditions (4.67 [95% CI, 3.10-7.05]) as well as for JAK1-specific inhibitors (4.69 [95% CI, 3.56-6.18]), combined JAK1 and JAK2 inhibitors (3.43 [95% CI, 2.14-5.49]), and tyrosine kinase 2 inhibitors (2.64 [95% CI, 1.44-4.86]).

Conclusions and Relevance

In this systematic review and meta-analysis, JAK inhibitor use was associated with an elevated odds of acne. Patients should be properly counseled on this potential adverse effect of these medications before treatment initiation. Future studies are needed to further elucidate the pathophysiology of this association.

Protein kinases: drug targets for immunological disorders

Protein kinases play a major role in cellular activation processes, including signal transduction by diverse immunoreceptors. Given their roles in cell growth and death and in the production of inflammatory mediators, targeting kinases has proven to be an effective treatment strategy, initially as anticancer therapies, but shortly thereafter in immune-mediated diseases. Herein, we provide an overview of the status of small molecule inhibitors specifically generated to target protein kinases relevant to immune cell function, with an emphasis on those approved for the treatment of immune-mediated diseases. The development of inhibitors of Janus kinases that target cytokine receptor signalling has been a particularly active area, with Janus kinase inhibitors being approved for the treatment of multiple autoimmune and allergic diseases as well as COVID-19. In addition, TEC family kinase inhibitors (including Bruton's tyrosine kinase inhibitors) targeting antigen receptor signalling have been approved for haematological malignancies and graft versus host disease. This experience provides multiple important lessons regarding the importance (or not) of selectivity and the limits to which genetic information informs efficacy and safety. Many new agents are being generated, along with new approaches for targeting kinases.

Resident cutaneous memory T cells: a clinical review of their role in chronic inflammatory dermatoses and potential as therapeutic targets

Resident memory T cells (T-RMs) remain in epithelial barrier tissues after antigen exposure and the initial effector phase. These T-RMs provide effective antimicrobial and anticancer immunity; however, pathogenic T-RMs have been shown to mediate various chronic inflammatory disorders in a variety of tissue types. In the skin, T-RMs are referred to as resident cutaneous memory T cells (cT-RMs). Understanding the mechanisms leading to the development and establishment of these cT-RMs populations may allow for targeted treatments that provide durable responses in chronic immune-mediated skin diseases, even after cessation. In this review, we summarize the evidence on cT-RMs as drivers of chronic inflammatory dermatoses, including psoriasis, vitiligo, atopic dermatitis, cutaneous lupus erythematosus and alopecia areata, among others. Data from in vitro, animal model and ex vivo human studies are presented, with a focus on the potential for cT-RMs to trigger acute disease flares, as well as recurrent disease, by establishing an immune 'memory' in the skin. Furthermore, the available data on the potential for existing and novel treatments to affect the development or survival of cT-RMs in the skin are synthesized. The data suggest a dynamic and rapidly growing area in the field of dermatology; however, we also discuss areas in need of greater research to allow for optimal treatment selection for long-term disease control.

Rational design of a JAK1-selective siRNA inhibitor for the modulation of autoimmunity in the skin

Inhibition of Janus kinase (JAK) family enzymes is a popular strategy for treating inflammatory and autoimmune skin diseases. In the clinic, small molecule JAK inhibitors show distinct efficacy and safety profiles, likely reflecting variable selectivity for JAK subtypes. Absolute JAK subtype selectivity has not yet been achieved. Here, we rationally design small interfering RNAs (siRNAs) that offer sequence-specific gene silencing of JAK1, narrowing the spectrum of action on JAK-dependent cytokine signaling to maintain efficacy and improve safety. Our fully chemically modified siRNA supports efficient silencing of JAK1 expression in human skin explant and modulation of JAK1-dependent inflammatory signaling. A single injection into mouse skin enables five weeks of duration of effect. In a mouse model of vitiligo, local administration of the JAK1 siRNA significantly reduces skin infiltration of autoreactive CD8+ T cells and prevents epidermal depigmentation. This work establishes a path toward siRNA treatments as a new class of therapeutic modality for inflammatory and autoimmune skin diseases.

Baseline Levels of Circulating Inflammatory Biomarkers Stratify Patients with Vitiligo Who Significantly Repigment after Treatment with Ruxolitinib Cream

BACKGROUND

Efficacy of ruxolitinib cream, a topical Jak1/Jak2 inhibitor, was demonstrated in a phase 2 trial in patients with vitiligo.

OBJECTIVE

This study aimed to characterize circulating inflammatory biomarker profiles in patients who demonstrated ≥50% improvement in facial Vitiligo Area Scoring Index scores by week 24 (group 1) and those who did not (group 2).

DESIGN

This was a posthoc analysis of a multicenter, randomized, double-blind, vehicle-controlled, phase 2 study in which screening was conducted between June 7, 2017 and March 21, 2018.

POPULATION

Patients aged between 18 and 75 years with vitiligo, including depigmentation affecting ≥0.5% of body surface area on the face and ≥3% of body surface area on nonfacial areas, were eligible.

INTERVENTION

Patients applied 1.5% ruxolitinib cream to lesions once or twice daily for 52 weeks.

MAIN OUTCOMES AND MEASURES

Patients were grouped by achievement of ≥50% improvement in facial Vitiligo Area Scoring Index at week 24. Proteomic analysis was performed on baseline serum samples.

RESULTS

Mean ± standard error facial Vitiligo Area Scoring Index in group 1 (n = 30) versus group 2 (n = 27) improved by 79.9 ± 4.0% versus 1.1 ± 7.3% and 91.9 ± 1.5% versus 25.1 ± 13.4% at weeks 24 and 52, respectively. Broad proteomic analysis revealed 76 proteins (of 1,104 tested) that were differentially expressed between groups 1 and 2 at baseline (P < 0.05). Ten distinct proteins were upregulated in group 1; 64 were elevated in group 2.

CONCLUSION

This analysis identified potential differences between patients who achieved ≥50% improvement in facial Vitiligo Area Scoring Index at 24 weeks and those who did not that require deeper scientific interrogation and may be important in stratifying therapeutic benefit for patients with vitiligo.

TRIAL REGISTRATION

The original study was registered at ClinicalTrials.gov, NCT03099304.

Topical ruxolitinib: A new treatment for vitiligo

Vitiligo is a chronic autoimmune skin disorder whose diagnosis is often psychologically upsetting. The efficacy of the available therapies, including topical corticosteroids and topical calcineurin inhibitors, has historically been limited and the management of vitiligo is still challenging. As vitiligo is a chronic disease limited to the skin, topical rather than systemic therapies may be preferable (especially among patients with localised lesions) to avoid the long-term side-effects of the latter. A topical formulation of ruxolitinib, a selective JAK1/2 inhibitor, has recently been approved in the United States for the treatment of non-segmental vitiligo in patients aged >12 years based on data from the phase III TRuE-V1 and TRuE-V2 clinical trials. The aim of this review is to describe the current evidence concerning the efficacy and safety of topical ruxolitinib in the treatment of vitiligo, and discuss issues regarding its use in younger children and pregnant or breastfeeding women, as well as the duration and durability of treatment. The promising results obtained so far suggest that 1.5% ruxolitinib cream is an effective means of treating vitiligo.

Understanding of Pathomechanisms and Clinical Practice for Vitiligo

Vitiligo is a disease caused by the acquired depletion of melanocytes and/or melanocyte precursor cells in response to genetic and environmental factors, resulting in depigmentation of the entire body. It is roughly divided into segmental and non-segmental vitiligo, and it has been found that abnormalities of melanocytes themselves and dysregulation of autoimmune responses to melanocytes are greatly involved in the pathology of non-segmental vitiligo. Segmental vitiligo pathology is largely unknown; however, it has been suggested that it may be caused by skin or melanocyte mosaicism. Treatments for vitiligo include topical therapy, ultraviolet therapy, and surgical transplantation, and it is extremely important to correctly understand the pathology to perform optimal treatment. In recent years, the development of vitiligo treatments using Janus kinase (JAK) inhibitors has progressed rapidly. We herein outline the latest pathology of vitiligo, from general vitiligo treatment to the progress of clinical trials using JAK inhibitors, along with what clinicians should consider in archiving precision medicine, including my own ideas thereon.

Implementation of the vitiligo area scoring index in clinical studies of patients with vitiligo: a scoping review

The vitiligo area scoring index (VASI) is a validated, reliable clinician-reported outcome measure widely used to assess the extent of skin depigmentation seen in patients with vitiligo and to measure patient responses to therapies for vitiligo in clinical trials. However, its implementation in studies is inconsistent and makes comparing results across different studies difficult. The aim of this scoping review is to summarize interventional clinical studies that applied the VASI to measure vitiligo and identify variability in VASI implementation. A systematic search of Ovid Medline, Embase, Web of Science, Cochrane, and ClinicalTrials.gov was performed. Interventional studies published between January 1946 and October 2020 that used the VASI as an outcome measure for assessing vitiligo response were reviewed for methodological approach. Great heterogeneity was found within the 55 included interventional studies that used VASI as an outcome measure. A total of 9 VASI subtypes were described by the authors within 10 intervention categories. VASI determined study eligibility in one study. Body surface area was most frequently established using inconsistent methods. We found unclear or ambiguously scaled assessments of depigmentation. Most VASI outcomes were reported as mean absolute difference, percentage VASI improvement, and percentage of patients who achieved the VASI endpoint. The VASI score was over 100 in one study. Our scoping review revealed many VASI methodology variations in interventional clinical studies of vitiligo. While VASI is a standard method to measure vitiligo changes, substantial heterogeneity in methodology limits reliable comparison and interpretation of findings from different clinical trials. Our findings may be used as a foundation to standardize the VASI outcome measure methodology, allowing for improved clinician training and rigorous data analysis across vitiligo research groups worldwide.

Increased Expression of Long Noncoding RNA LOC100506314 in T cells from Patients with Nonsegmental Vitiligo and Its Contribution to Vitiligo Pathogenesis

This study aimed to identify the abnormal expression of long noncoding RNAs (lncRNAs) in T cells from patients with vitiligo and to investigate their functional roles in the immune system. Using microarray analysis, the expression levels of RNA transcripts in T cells from patients with vitiligo and controls were compared. We identified several genes and validated their expression levels in T cells from 41 vitiligo patients and 41 controls. The biological functions of the lncRNAs were studied in a transfection study using an RNA pull-down assay, followed by proteomic analysis and western blotting. The expression levels of 134 genes were significantly increased, and those of 142 genes were significantly decreased in T cells from vitiligo patients. After validation, six genes had increased expression, and three genes had decreased expression in T cells from patients with vitiligo. T-cell expression of LOC100506314 was increased in vitiligo, especially CD4+, but not CD8+ T cells. The expression levels of LOC100506314 in CD4+ T cells was positively and significantly associated with the severity of vitiligo. LOC100506314 was bound to the signal transducer and activator of transcription 3 (STAT3) and macrophage migration inhibitory factor (MIF). Enhanced expression of LOC100506314 inhibited the phosphorylation of STAT3, protein kinase B (AKT), and extracellular signal-regulated protein kinases (ERK), as well as the levels of nuclear protein of p65 and the expression of IL-6 and IL-17 in Jurkat cells and T cells from patients with vitiligo. In conclusion, this study showed that the expression of LOC100506314 was elevated in CD4+ T cells from patients with vitiligo and associated the severity of vitiligo. LOC100506314 interacted with STAT3 and MIF and inhibited IL-6 and IL-17 expression by suppressing the STAT3, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), AKT, and ERK pathways. Enhanced expression of LOC100506314 in T cells may be a potential treatment strategy for vitiligo.

Diagnosis and Management of Dermatologic Adverse Events from Systemic Melanoma Therapies

The advent of protein kinase inhibitors and immunotherapy has profoundly improved the management of advanced melanoma. However, with these therapeutic advancements also come drug-related toxicities that have the potential to affect various organ systems. We review dermatologic adverse events from targeted (including BRAF and MEK inhibitor-related) and less commonly used melanoma treatments, with a focus on diagnosis and management. As immunotherapy-related toxicities have been extensively reviewed, herein, we discuss injectable talimogene laherparepvec and touch on recent breakthroughs in the immunotherapy space. Dermatologic adverse events may severely impact quality of life and are associated with response and survival. It is therefore essential that clinicians are aware of their diverse presentations and management strategies.

JAK-STAT pathway inhibitors in dermatology

The JAK-STAT signaling pathway mediates important cellular processes such as immune response, carcinogenesis, cell differentiation, division and death. Therefore, drugs that interfere with different JAK-STAT signaling patterns have potential indications for various medical conditions. The main dermatological targets of JAK-STAT pathway inhibitors are inflammatory or autoimmune diseases such as psoriasis, vitiligo, atopic dermatitis and alopecia areata; however, several dermatoses are under investigation to expand this list of indications. As JAK-STAT pathway inhibitors should gradually occupy a relevant space in dermatological prescriptions, this review presents the main available drugs, their immunological effects, and their pharmacological characteristics, related to clinical efficacy and safety, aiming to validate the best dermatological practice.

Real-World Treatment Patterns in Patients with Vitiligo in the United States

INTRODUCTION

Vitiligo is an autoimmune disorder resulting in skin depigmentation, with limited approved treatment options. This study evaluated medication utilization and treatment patterns among patients in the first year following vitiligo diagnosis.

METHODS

This retrospective analysis of claims data from the Merative® MarketScan Research Databases included patients aged ≥ 12 years newly diagnosed with vitiligo. Patients were identified between October 1, 2016, and April 30, 2021, and had ≥ 12 months of continuous enrollment pre- and post-vitiligo diagnosis. Medication use, treatment line of therapy, time to and number of medication claims, and length of therapy were reported in the 12 months post-vitiligo diagnosis. Results are reported separately for treatment initiators post-vitiligo diagnosis, patients with moderate-to-severe vitiligo, and adolescents (aged 12-17 years).

RESULTS

A total of 19,335 patients were included in the analysis, with half (N = 9648, 49.9%) not receiving any treatment during the 12-month follow-up. Switching was minimal among treatment initiators (N = 5845) in the 12 months post-vitiligo diagnosis, with the most frequent first-line treatments being high-potency topical corticosteroids (25.4%), oral corticosteroids (23.1%), and topical calcineurin inhibitors (TCI, 14.7%). Adolescents initiating treatment (N = 486) most frequently received TCI (30.9%) as first-line therapy. Patients with moderate-to-severe vitiligo (N = 3462) were very likely to receive treatment during follow-up, with only 1.5% not receiving treatment. Among patients with no vitiligo treatment prior to diagnosis, time to first medication claim ranged from 51.9 days (standard deviation [SD], 84.0) for TCI to 178.6 days (SD 116.0) for systemic immunosuppressants; mean total days supplied ranged from 14.4 days (SD 27.1) for oral corticosteroids to 121.0 (SD 114.0) for immunosuppressants.

CONCLUSION

In this real-world study, a high proportion of patients did not receive any treatment. Among those receiving treatment, most were unlikely to switch or use a combination of treatments within the first year of vitiligo diagnosis.

Non-invasive Imaging Techniques for Monitoring Cellular Response to Treatment in Stable Vitiligo

Punch grafting procedures, where small pieces of normal skin are transplanted into stable vitiligo patches, results in repigmentation in only half of patients treated, yet the factors that determine whether a patient responds to treatment or not are still unknown. Reflectance confocal microscopy (RCM) is adept at visualizing melanocyte migration and epidermal changes over large areas while multiphoton microscopy (MPM) can capture metabolic changes in keratinocytes. With the overall goal of identifying optical biomarkers for early treatment response, we followed 12 vitiligo lesions undergoing punch grafting. Dendritic melanocytes adjacent to the graft site were observed before clinical evidence of repigmentation in treatment responsive patients but not in treatment non-responsive patients, suggesting that the early visualization of melanocytes is indicative of a therapeutic response. Keratinocyte metabolic changes in vitiligo skin adjacent to the graft site also correlated with treatment response, indicating that a keratinocyte microenvironment that more closely resembles normal skin is more hospitable for migrating melanocytes. Taken together, these studies suggest that successful melanocyte transplantation requires both the introduction of new melanocytes and modulation of the local tissue microenvironment.

Pharmacological inhibition of demethylzeylasteral on JAK-STAT signaling ameliorates vitiligo

BACKGROUND

The activation of CD8⁺ T cells and their trafficking to the skin through JAK-STAT signaling play a central role in the development of vitiligo. Thus, targeting this key disease pathway with innovative drugs is an effective strategy for treating vitiligo. Natural products isolated from medicinal herbs are a useful source of novel therapeutics. Demethylzeylasteral (T-96), extracted from Tripterygium wilfordii Hook F, possesses immunosuppressive and anti-inflammatory properties.

METHODS

The efficacy of T-96 was tested in our mouse model of vitiligo, and the numbers of CD8⁺ T cells infiltration and melanocytes remaining in the epidermis were quantified using whole-mount tail staining. Immune regulation of T-96 in CD8⁺ T cells was evaluated using flow cytometry. Pull-down assay, mass spectrum analysis, molecular docking, knockdown and overexpression approaches were utilized to identify the target proteins of T-96 in CD8⁺ T cells and keratinocytes.

RESULTS

Here, we found that T-96 reduced CD8⁺ T cell infiltration in the epidermis using whole-mount tail staining and alleviated the extent of depigmentation to a comparable degree of tofacitinib (Tofa) in our vitiligo mouse model. In vitro, T-96 decreased the proliferation, CD69 membrane expression, and IFN-γ, granzyme B, (GzmB), and perforin (PRF) levels in CD8⁺ T cells isolated from patients with vitiligo. Pull-down assays combined with mass spectrum analysis and molecular docking showed that T-96 interacted with JAK3 in CD8⁺ T cell lysates. Furthermore, T-96 reduced JAK3 and STAT5 phosphorylation following IL-2 treatment. T-96 could not further reduce IFN-γ, GzmB and PRF expression following JAK3 knockdown or inhibit increased immune effectors expression upon JAK3 overexpression. Additionally, T-96 interacted with JAK2 in IFN-γ-stimulated keratinocytes, inhibiting the activation of JAK2, decreasing the total and phosphorylated protein levels of STAT1, and reducing the production and secretion of CXCL9 and CXCL10. T-96 did not significantly inhibit STAT1 and CXCL9/10 expression following JAK2 knockdown, nor did it suppress upregulated STAT1-CXCL9/10 signaling upon JAK2 overexpression. Finally, T-96 reduced the membrane expression of CXCR3, and the culture supernatants pretreated with T-96 under IFN-γ stressed keratinocytes markedly blocked the migration of CXCR3⁺CD8⁺ T cells, similarly to Tofa in vitro.

CONCLUSION

Our findings demonstrated that T-96 might have positive therapeutic responses to vitiligo by pharmacologically inhibiting the effector functions and skin trafficking of CD8⁺ T cells through JAK-STAT signaling.

JAK inhibitors in vitiligo: what they hit and what they miss - an immunopathogenesis based exposition of existing evidence

INTRODUCTION

Vitiligo is an autoimmune disorder which presents as depigmented macules due to selective loss of melanocytes. Heightened expression of Janus Kinase Signal transducers and activators of transcription (JAK STAT) pathway, which mediate cytokines action, suggest that targeting this signaling pathway may be an effective option.

AREAS COVERED

A PubMed search was carried out with the broad key words 'JAK,' 'vitiligo' from 2016 to 2023. We also analyzed papers where tissue-based JAK expression was studied, with or without concomitant treatment with JAK inhibitors. We address the role of JAK inhibitors in vitiligo and their effect on repigmentation of lesions.

EXPERT OPINION

While JAK inhibitors help in cessation of disease progression, they have no in vivo action on melanocyte proliferation and hence cannot result in re-pigmentation as a monotherapy. There is a need for tissue-based JAK and cytokine-based studies with post-treatment expression data to validate the role of this class of drugs in vitiligo. There is as yet no data to suggest that selective JAK inhibitors are superior to pan JAK inhibitors for vitiligo. JAK inhibitors are useful in active disease and effectively modulate the cytokine mediated autoimmune dammage and makes them singularly superior to oral glucocorticosteroids.

Skin Pigmentation Types, Causes and Treatment-A Review

Human skin pigmentation and melanin synthesis are incredibly variable, and are impacted by genetics, UV exposure, and some drugs. Patients' physical appearance, psychological health, and social functioning are all impacted by a sizable number of skin conditions that cause pigmentary abnormalities. Hyperpigmentation, where pigment appears to overflow, and hypopigmentation, where pigment is reduced, are the two major classifications of skin pigmentation. Albinism, melasma, vitiligo, Addison's disease, and post-inflammatory hyperpigmentation, which can be brought on by eczema, acne vulgaris, and drug interactions, are the most common skin pigmentation disorders in clinical practice. Anti-inflammatory medications, antioxidants, and medications that inhibit tyrosinase, which prevents the production of melanin, are all possible treatments for pigmentation problems. Skin pigmentation can be treated orally and topically with medications, herbal remedies, and cosmetic products, but a doctor should always be consulted before beginning any new medicine or treatment plan. This review article explores the numerous types of pigmentation problems, their causes, and treatments, as well as the 25 plants, 4 marine species, and 17 topical and oral medications now on the market that have been clinically tested to treat skin diseases.

Etiopathogenesis and Emerging Methods for Treatment of Vitiligo

Vitiligo is an acquired chronic depigmenting disorder of skin. It is mostly asymptomatic and characterized by amelanotic macules and patches that affects 0.5% to 2% of the world's population. The etiology of vitiligo has not been clearly elucidated and multiple theories have been proposed regarding the causes of the disorder. Among the most prevalent theories, the genetic predisposition, oxidative stress theory, promotion of cellular stress and pathologic influence of lymphocytes T have been highlighted. As a result of increases in in-depth knowledge concerning the pathogenetic processes in vitiligo, we review the most recent information concerning its etiopathogenesis and treatment methods including topical and oral Janus kinase inhibitors, prostaglandins and their analogues, namely afamelanotide, Wnt/β-catenin-signaling agonists and cell-based therapies. Topical ruxolitinib has been registered for vitiligo treatment, whereas other agents as oral ritlecitinib, afamelanotide and latanoprost have been studied in ongoing clinical trials. New highly effective therapeutic strategies may be developed thanks to molecular and genetic studies.

Sexual dimorphism in melanocyte stem cell behavior reveals combinational therapeutic strategies for cutaneous repigmentation

Vitiligo is an autoimmune skin disease caused by cutaneous melanocyte loss. Although phototherapy and T cell suppression therapy have been widely used to induce epidermal repigmentation, full pigmentation recovery is rarely achieved due to our poor understanding of the cellular and molecular mechanisms governing this process. Here, we identify unique melanocyte stem cell (McSC) epidermal migration rates between male and female mice, which is due to sexually dimorphic cutaneous inflammatory responses generated by ultra-violet B exposure. Using genetically engineered mouse models, and unbiased bulk and single-cell mRNA sequencing approaches, we determine that manipulating the inflammatory response through cyclooxygenase and its downstream prostaglandin product regulates McSC proliferation and epidermal migration in response to UVB exposure. Furthermore, we demonstrate that a combinational therapy that manipulates both macrophages and T cells (or innate and adaptive immunity) significantly promotes epidermal melanocyte re-population. With these findings, we propose a novel therapeutic strategy for repigmentation in patients with depigmentation conditions such as vitiligo.

Evolving cognition of the JAK-STAT signaling pathway: autoimmune disorders and cancer

The Janus kinase (JAK) signal transducer and activator of transcription (JAK-STAT) pathway is an evolutionarily conserved mechanism of transmembrane signal transduction that enables cells to communicate with the exterior environment. Various cytokines, interferons, growth factors, and other specific molecules activate JAK-STAT signaling to drive a series of physiological and pathological processes, including proliferation, metabolism, immune response, inflammation, and malignancy. Dysregulated JAK-STAT signaling and related genetic mutations are strongly associated with immune activation and cancer progression. Insights into the structures and functions of the JAK-STAT pathway have led to the development and approval of diverse drugs for the clinical treatment of diseases. Currently, drugs have been developed to mainly target the JAK-STAT pathway and are commonly divided into three subtypes: cytokine or receptor antibodies, JAK inhibitors, and STAT inhibitors. And novel agents also continue to be developed and tested in preclinical and clinical studies. The effectiveness and safety of each kind of drug also warrant further scientific trials before put into being clinical applications. Here, we review the current understanding of the fundamental composition and function of the JAK-STAT signaling pathway. We also discuss advancements in the understanding of JAK-STAT-related pathogenic mechanisms; targeted JAK-STAT therapies for various diseases, especially immune disorders, and cancers; newly developed JAK inhibitors; and current challenges and directions in the field.

Targeting the elevated IFN-γ in vitiligo patients by human anti- IFN-γ monoclonal antibody hampers direct cytototoxicity in melanocyte

BACKGROUND

Vitiligo is an autoimmune disease that progressively destroys melanocytes in the skin, resulting in patchy disfiguring depigmentation. The direct pathological effect of IFN-γ, CXCL10 to the melanocytes in vitiligo has been reported, but there are contradictory results to which cytokine exerts the critical cytotoxic effect on melanocytes.

OBJECTIVE

The overarching goal was to study the direct toxicity of highly expressed cytokine in vitiligo skin lesions to melanocytes.

METHODS

We obtained the interstitial fluid analyte from lesion and non-lesion skin of vitiligo patients and healthy control and sent for high sensitivity multiplex cytokine panel. We further performed functional study to identify the direct toxicity effect of the highly expressed cytokines.

RESULTS

We found a significant elevation of IFN-γ, CXCL9, CXCL10, CXCL11 in the vitiligo skin. Ex vivo melanocyte studies support the direct role of IFN-γ per se in melanocyte cell loss, increased oxidative stress and melanogenesis disruption. Interestingly, we found that IFN-γ regulated cell death through oxidative stress-related ferroptosis cell death, which may initiate autoimmunity in vitiligo. In contrast to blocking selected cell death pathway, our in vitro study supports the rescue effect of human anti-IFN-γ monoclonal antibody 2A6Q to IFN-γ induced cell death, oxidative stress, and loss of function in melanocytes by interrupting IFN-γ signaling, which may be a potential therapeutic option for vitiligo.

CONCLUSION

This study further confirms the direct of toxicity effect of IFN-γ per se towards melanocyte in vitiligo skin and the potential utility of human anti-IFN-γ monoclonal antibody in treating vitiligo.

JAK inhibitors in dermatology: the road travelled and path ahead, a narrative review

INTRODUCTION

Numerous cutaneous dermatoses mediated by cytokines depend on the JAK STAT pathway for intracellular signaling. JAK inhibitors form a useful therapeutic approach in treating these conditions. The literature on effectiveness of JAK inhibitors in treatment of alopecia areata, vitiligo, atopic dermatitis, psoriasis and several other inflammatory and autoimmune diseases is growing, although very few conditions have sufficiently well performed studies to their credit and barring a few indications, their use in rest remains empirical as yet.

AREAS COVERED

A search of the PubMed database was made using the keywords Janus kinase inhibitors OR JAK inhibitors AND dermatology with the time duration limited to the last 5 years. Here, we review the JAK STAT pathway and the various conditions in which JAK inhibitors are currently used in dermatology and other conditions their use is being explored in.

EXPERT OPINION

The pathology of a large number of dermatological disorders is mediated via inflammatory cytokines which signal via the JAK STAT pathway. JAKinibs have shown great promise in treating cutaneous disorders refractory to conventional therapy. Their current clinical use in dermatology is based on robust evidence (for some), and anecdotal evidence for most other dermatoses.

Vitiligo, from Pathogenesis to Therapeutic Advances: State of the Art

Vitiligo is an acquired hypopigmentation of the skin due to a progressive selective loss of melanocytes; it has a prevalence of 1-2% and appears as rounded, well-demarcated white macules. The etiopathology of the disease has not been well defined, but multiple factors contribute to melanocyte loss: metabolic abnormalities, oxidative stress, inflammation, and autoimmunity. Therefore, a convergence theory was proposed that combines all existing theories into a comprehensive one in which several mechanisms contribute to the reduction of melanocyte viability. In addition, increasingly in-depth knowledge about the disease's pathogenetic processes has enabled the development of increasingly targeted therapeutic strategies with high efficacy and fewer side effects. The aim of this paper is, by conducting a narrative review of the literature, to analyze the pathogenesis of vitiligo and the most recent treatments available for this condition.

Systemic therapies in vitiligo: a review

Vitiligo is characterized by the development of depigmented macules and patches. Autoimmunity has been established as a factor in disease pathogenesis, leading to utilization of immunosuppressive agents. Topical immunosuppressants are commonly used; however, this treatment modality is often cumbersome and inefficient, as many patients have active disease with extensive body surface area involvement. Prompt and aggressive treatment of vitiligo is important, as this may prevent progression and improve quality of life. To meet these challenges and improve patient outcomes, interest in systemic therapies has grown. Currently, oral therapies are rarely prescribed, likely due to concerns with systemic side effects and unclear efficacy. This article provides a brief overview on the use of systemic agents in treating vitiligo in order to provide additional therapeutic options to clinicians.

Vitiligo Treatments: Review of Current Therapeutic Modalities and JAK Inhibitors

Vitiligo is a chronic autoimmune disease characterized by loss of pigment of the skin, affecting 0.5-2% of the population worldwide. It can have a significant impact on patients' quality of life. In recent years, there has been significant progress in our understanding of the pathogenesis of vitiligo. It is believed that vitiligo develops due to a complex combination of genetics, oxidative stress, inflammation, and environmental triggers. Conventional treatments include camouflage, topical corticosteroids, topical calcineurin inhibitors, oral corticosteroids, phototherapy, and surgical procedures, with the treatment regimen dependent on the patient's preferences and characteristics. With increased understanding of the importance of the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway in the pathogenesis of vitiligo, treatment has expanded to include the first US FDA-approved cream to repigment patients with vitiligo. This review summarizes our understanding of the major mechanisms involved in the pathogenesis of vitiligo and its most common available treatments.

The use of Janus kinase inhibitors and narrowband ultraviolet B combination therapy in non-segmental vitiligo

Vitiligo is a depigmentation disorder of the skin that occurs secondary to the destruction of melanocytes by an immune-mediated process. Vitiligo clinically presents with depigmented macules and patches, most commonly on the face, acral sites, and genitalia. It can be characterized as generalized or localized based on distribution. The localized form can be further divided into segmental (linear, band-like, or Blaschkoid) and non-segmental vitiligo. The classical treatment of vitiligo includes topical steroids, pulsed oral steroids in unstable vitiligo, phototherapy, a combination of steroid therapy and phototherapy, surgical grafting, as well as intentional depigmentation therapy in severe cases. However, recent advances in understanding the immune mechanisms implicated in the pathogenesis of vitiligo have led to the use of an FDA-approved topical Janus kinase (JAK) inhibitors for vitiligo. Despite this novel therapy advancement, we recommend the addition of narrowband ultraviolet B (NB-UVB) to JAK inhibitors in patients with extensive and progressive lesions, or those not fully responsive to JAK inhibitor monotherapy.

A review of JAK and IL-23 inhibitors to treat vitiligo

Vitiligo is an autoimmune skin disorder resulting in the depigmentation of skin characterised by patches of varying sizes and shapes. A common disorder of pigmentation that affects 0.5%-2% of the global population. Despite its well-understood autoimmune pathogenesis, the targets for effective cytokine intervention remain unclear. Current first-line treatments include oral or topical corticosteroids, calcineurin inhibitors and phototherapy. These treatments are limited, have varying efficacies, and are associated with significant adverse events or can be time-consuming. Therefore, biologics should be explored as a potential treatment for vitiligo. There are currently limited data for the use of JAK and IL-23 inhibitors for vitiligo. A total of 25 studies were identified in the review. There is promising evidence regarding the use of JAK and IL-23 inhibitors for the treatment of vitiligo.