Oral ruxolitinib induces hair regrowth in patients with moderate-to-severe alopecia areata

Improvement in Measures of Quality of Life and Symptoms of Anxiety and Depression in Patients with Severe Alopecia Areata Achieving Sustained Scalp Hair Regrowth with Baricitinib

INTRODUCTION

Alopecia areata (AA) is an autoimmune disease associated with high rates of emotional and psychosocial distress. The analysis reported here describes the evolution of measures assessing health-related quality of life (HRQoL) and symptoms of anxiety and depression up to week 104 in patients who achieved sustained scalp hair regrowth during treatment with baricitinib in the BRAVE-AA phase III trials.

METHODS

This post-hoc analysis included data from the double-blind, parallel-group, randomized, placebo-controlled phase III trials BRAVE-AA1 (ClinicalTrials.gov number: NCT03570749) and BRAVE-AA2 (ClinicalTrials.gov number: NCT03899259). Adults with severe AA (defined as a Severity of Alopecia Tool [SALT] score ≥ 50) randomized to baricitinib 4 mg or baricitinib 2 mg at baseline who achieved SALT score ≤ 20 by week 36 and maintained SALT score ≤ 20 through week 104 on the same dose of baricitinib were included in this analysis of integrated data. Scalp hair regrowth (SALT score) and improvements in Skindex-16 AA Scale and Hospital Anxiety and Depression Scale (HADS) domain scores were analyzed over the 104-week period using descriptive statistics.

RESULTS

In total, 131 patients (88 on baricitinib 4 mg and 43 on baricitinib 2 mg) were included in this analysis. Across the two groups, the mean age (standard deviation) was 37.2 years (12.7), and 84 (64.1%) patients were female. The interquartile range) for time to achieve a SALT score ≤ 20 for patients treated with baricitinib 4 mg and baricitinib 2 mg was 13.1 and 19.6 weeks, respectively. By week 104, 91% (baricitinib 2 mg) and 96% (baricitinib 4 mg) of patients had achieved a SALT score ≤ 10 on baricitinib treatment. In both groups, progressive improvements in the Skindex-16 AA and HADS domain scores were observed up to week 104.

CONCLUSION

This analysis of adults with severe AA treated with baricitinib revealed that achievement of sustained clinically meaningful scalp hair regrowth (SALT score ≤ 20) was associated with improvements in both measures of HRQoL and symptoms of anxiety and depression up to week 104.

Novel investigational drugs for alopecia areata and future perspectives

INTRODUCTION

Alopecia areata (AA) is an immune-mediated disease that causes non-scarring hair loss. While acute, solitary patches often spontaneously remit, developing secondary patches or failure of the disease to resolve within 6-12 months predicts a poor prognosis, with an increased risk of alopecia totalis or universalis. Chronic AA increases the risk of depression and suicidality and reduces quality of life. Treatment options for chronic or acute diffuse AA were previously limited to corticosteroids and traditional immunomodulators. Two Janus Kinase (JAK) inhibitors are now approved for the treatment of chronic AA.

AREAS COVERED

The results of landmark phase 3 trials for three JAK inhibitors, baricitinib, ritlecitinib, and deuruxolitinib are discussed. Evidence for other JAK inhibitors, biologics, and phosphodiesterase-4 inhibitors are also presented. Therapies currently undergoing clinical trials are listed.

EXPERT OPINION

JAK inhibitors are a safe and efficacious treatment of moderate-to-severe AA. Early intervention, regardless of severity, allows for improved treatment efficacy. It is uncertain how long patients should remain on JAK inhibitors; discontinuation often leads to relapse. A black-box warning for JAK inhibitors was extrapolated from safety data in a rheumatoid arthritis cohort; recent meta-analyses of JAK inhibitors used in dermatology cohorts do not demonstrate the same risk profile.

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.

Precision Dermatology: A Review of Molecular Biomarkers and Personalized Therapies

The evolution of personalized medicine in dermatology signifies a transformative shift towards individualized treatments, driven by the integration of biomarkers. These molecular indicators serve beyond diagnostics, offering insights into disease staging, prognosis, and therapeutic monitoring. Specific criteria guide biomarker selection, ensuring attributes like specificity, sensitivity, cost feasibility, stability, rapid detection, and reproducibility. This literature review, based on data from PubMed, SCOPUS, and Web of Science, explores biomarkers in Hidradenitis Suppurativa (HS), Psoriasis, Atopic Dermatitis (AD), Alopecia Areata (AA), Vitiligo, and Chronic Spontaneous Urticaria (CSU). In HS, TNF-α, IL-1β, and MMPs serve as biomarkers, influencing targeted therapies like adalimumab and anakinra. Psoriasis involves biomarkers such as TNF-α, IL-23, and HLA genes, shaping treatments like IL23 and IL17 inhibitors. AD biomarkers include ECP, IL-4, IL-13, guiding therapies like dupilumab and tralokinumab. For AA, lipocalin-2, cytokines, and genetic polymorphisms inform JAK inhibitors' use. Vitiligo biomarkers range from cytokines to genetic markers like TYR, TYRP1, guiding treatments like JAK inhibitors. CSU biomarkers encompass IgE, cytokines, and autologous serum tests, influencing therapies like omalizumab and cyclosporine. Comparing conditions, common proinflammatory markers reveal limited specificity. While some biomarkers aid diagnosis and standard treatments, others hold more scientific than clinical value. Precision medicine, driven by biomarkers, has shown success in skin malignancies. Future directions involve AI-powered algorithms, nanotechnology, and multi-omics integration for personalized dermatological care.

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.

Identification of SLC40A1, LCN2, CREB5, and SLC7A11 as ferroptosis-related biomarkers in alopecia areata through machine learning

Alopecia areata (AA) is a common non-scarring hair loss condition driven by the collapse of immune privilege and oxidative stress. The role of ferroptosis, a type of cell death linked to oxidative stress, in AA is yet to be explored, even though it's implicated in various diseases. Using transcriptome data from AA patients and controls from datasets GSE68801 and GSE80342, we aimed to identify AA diagnostic marker genes linked to ferroptosis. We employed Single-sample gene set enrichment analysis (ssGSEA) for immune cell infiltration evaluation. Correlations between ferroptosis-related differentially expressed genes (FRDEGs) and immune cells/functions were identified using Spearman analysis. Feature selection was done through Support vector machine-recursive feature elimination (SVM-RFE) and LASSO regression models. Validation was performed using the GSE80342 dataset, followed by hierarchical internal validation. We also constructed a nomogram to assess the predictive ability of FRDEGs in AA. Furthermore, the expression and distribution of these molecules were confirmed through immunofluorescence. Four genes, namely SLC40A1, LCN2, CREB5, and SLC7A11, were identified as markers for AA. A prediction model based on these genes showed high accuracy (AUC = 0.9052). Immunofluorescence revealed reduced expression of these molecules in AA patients compared to normal controls (NC), with SLC40A1 and CREB5 showing significant differences. Notably, they were primarily localized to the outer root sheath and in proximity to the sebaceous glands. Our study identified several ferroptosis-related genes associated with AA. These findings, emerging from the integration of immune cell infiltration analysis and machine learning, contribute to the evolving understanding of diagnostic and therapeutic strategies in AA. Importantly, this research lays a solid foundation for subsequent studies exploring the intricate relationship between AA and ferroptosis.

Alopecia areata: What's new in the diagnosis and treatment with JAK inhibitors?

Alopecia areata (AA) affects individuals of all ages and is intractable in severe relapsing cases. Dermatologists and other healthcare providers should consider AA in the medical context and prioritize treatment. Several randomized controlled clinical studies on Janus kinase (JAK) inhibitors with different specificities for the treatment of AA are ongoing. These studies have encouraged us to appreciate the importance of a definitive diagnosis and accurate evaluation of AA before and during treatment. Following our previous review article in 2017, here we provide the second part of this two-review series on the recent progress in the multidisciplinary approaches to AA from more than 1800 articles published between July 2016 and December 2022. This review focuses on the evaluation, diagnosis, and treatment of AA. We also provide the latest information on the safety and efficacy of JAK inhibitors for the treatment of AA and describe their mechanisms of action.

Treatments for Moderate-to-Severe Alopecia Areata: A Systematic Narrative Review

Treatments for alopecia areata (AA) have traditionally been prescribed off-label, and there has been no universal agreement on how to best manage the condition. Baricitinib is the first oral selective Janus kinase (JAK) inhibitor approved for the treatment of adults with severe AA. As a better understanding of the evidence supporting the management of AA in clinical practice is needed, we conducted a systematic literature review and subsequent narrative review to describe available evidence pertaining to the efficacy and tolerability of treatments currently recommended for adults with moderate-to-severe forms of AA. From 2557 identified records, a total of 53 records were retained for data extraction: 9 reported data from 7 randomized controlled trials (RCTs) versus placebo, and 44 reported data from unique RCTs with no placebo arm, non-randomized trials, or observational studies. Across drug classes, data were reported heterogeneously, with little consistency of data collection or clinical endpoints used. The most robust evidence was for the JAK inhibitor class, in particular the JAK1/JAK2 inhibitor baricitinib. Five RCTs (three for baricitinib) demonstrated a consistent benefit of JAK inhibitor therapy over placebo across various clinical outcomes in adult patients with at least 50% scalp hair loss. Overall, hair regrowth varied widely for the other drug classes and was generally low for patients with moderate-to-severe AA. Relapses were commonly observed during treatment and upon discontinuation. Adverse effects were generally consistent with the known safety profile of each intervention. The heterogeneity observed prevented the conduct of a network meta-analysis or an indirect comparison of different treatments. We found that the current management of patients with moderate-to-severe AA often relies on the use of treatments that have not been well evaluated in clinical trials. The most robust evidence identified supported the use of baricitinib, and other oral JAK inhibitors, in patients with severe AA.

Inhibition of T-cell activity in alopecia areata: recent developments and new directions

Alopecia areata (AA) is an autoimmune disease that has a complex underlying immunopathogenesis characterized by nonscarring hair loss ranging from small bald patches to complete loss of scalp, face, and/or body hair. Although the etiopathogenesis of AA has not yet been fully characterized, immune privilege collapse at the hair follicle (HF) followed by T-cell receptor recognition of exposed HF autoantigens by autoreactive cytotoxic CD8+ T cells is now understood to play a central role. Few treatment options are available, with the Janus kinase (JAK) 1/2 inhibitor baricitinib (2022) and the selective JAK3/tyrosine kinase expressed in hepatocellular carcinoma (TEC) inhibitor ritlecitinib (2023) being the only US Food and Drug Administration-approved systemic medications thus far for severe AA. Several other treatments are used off-label with limited efficacy and/or suboptimal safety and tolerability. With an increased understanding of the T-cell-mediated autoimmune and inflammatory pathogenesis of AA, additional therapeutic pathways beyond JAK inhibition are currently under investigation for the development of AA therapies. This narrative review presents a detailed overview about the role of T cells and T-cell-signaling pathways in the pathogenesis of AA, with a focus on those pathways targeted by drugs in clinical development for the treatment of AA. A detailed summary of new drugs targeting these pathways with expert commentary on future directions for AA drug development and the importance of targeting multiple T-cell-signaling pathways is also provided in this review.

A randomized, double-blind, placebo-controlled phase II study to evaluate the efficacy and safety of ivarmacitinib (SHR0302) in adult patients with moderate-to-severe alopecia areata

BACKGROUND

Alopecia areata (AA) is a CD8+ T cell-mediated autoimmune disease characterized by nonscarring hair loss. Ivarmacitinib, which is a selective oral Janus kinase 1 inhibitor, may interrupt certain cytokine signaling implicated in the pathogenesis of AA.

OBJECTIVE

To evaluate the efficacy and safety of ivarmacitinib in adult patients with AA who have ≥25% scalp hair loss.

METHODS

Eligible patients were randomized 1:1:1:1 to receive ivarmacitinib 2, 4, or 8 mg once daily or placebo for 24 weeks. The primary end point was the percentage change from baseline in the Severity of Alopecia Tool score at week 24.

RESULTS

A total of 94 patients were randomized. At week 24, the least squares mean difference in the percentage change from baseline in the Severity of Alopecia Tool score for ivarmacitinib 2, 4, and 8 mg and placebo groups were -30.51% (90% CI, -45.25, -15.76), -56.11% (90% CI, -70.28, -41.95), -51.01% (90% CI, -65.20, -36.82), and -19.87% (90% CI, -33.99, -5.75), respectively. Two serious adverse events-follicular lymphoma and COVID-19 pneumonia-were reported.

LIMITATIONS

A small sample size limits the generalizability of the results.

CONCLUSION

Treatment with ivarmacitinib 4 and 8 mg doses in patients with moderate and severe AA for 24 weeks was efficacious and generally tolerated.

Janus kinase inhibitors for alopecia areata: A narrative review

The Janus kinase (JAK) and Signal Transducer and Activator of Transcription (STAT) pathway has been identified as a key player in the pathophysiology of alopecia areata and a potential target for therapy. Here, we give a narrative review of what is known about Janus kinase inhibitors in alopecia areata. Several clinical trials as well as smaller studies have demonstrated hair regrowth and remission with oral Janus kinase inhibitors therapy, even in patients who failed conventional treatment. Baricitinib is the only US FDA-approved treatment for alopecia areata but data for other oral Janus kinase inhibitors such as tofacitinib, ruxolitinib and ritlecitinib are also promising. Fewer clinical trials have investigated topical Janus kinase inhibitors for alopecia areata, with many of them terminated early due to unfavourable results. Overall, Janus kinase inhibitors are an efficacious addition to the therapeutic arsenal for treatment-refractory alopecia areata. Further work is needed to examine the effects of long-term usage of Janus kinase inhibitors, the efficacy of topical Janus kinase inhibitors, as well as to identify biomarkers that could predict differential therapeutic responses to the various Janus kinase inhibitors.

Treatment of in vitro generated Langerhans cells with JAK-STAT inhibitor reduces their inflammatory potential

Alopecia areata (AA) is a condition in which hair is lost in small regions or over the entire body. It has a prevalence of 1 in 1000 and has a great impact on psychological wellbeing. AA is generally considered an autoimmune disease in which a collapse of the immune privilege system of the hair follicle has shown to play an important role, potentially driven by interferon gamma (IFN-γ). The most prominent cells located in or around the hair follicle in AA are Langerhans cells, CD4+ or CD8+ T cells, macrophages and mast cells. Langerhans cells, specialized dendritic cells, are resident in the epidermis and are known to associate with hair follicles. Therefore, we aimed to develop in vitro generated Langerhans cells contributing as an in vitro model of disease. In vitro models provide insight into the behaviour of cells and are a valuable tool before being in need of an animal model or patient samples. For this, Langerhans-like cells were generated from CD14+ monocytes in the presence of GM-CSF and TGF-β. After 10 days of cell culture, Langerhans-like cells express CD207 and CD1a but lack CD209 expression as well as Birbeck granules. Next, Langerhans-like cells were exposed to inflammatory conditions and the effect of different AA treatments was investigated. All treatments-diphencyprone contact immunotherapy, UV-B light therapy and JAK-STAT inhibition-affect the expression of costimulatory and skin-homing markers on Langerhans-like cells. Importantly, also the T cell stimulatory capacity of Langerhans-like cells was significantly reduced following treatment under inflammatory conditions. Noteworthy, JAK-STAT inhibition outperformed conventional AA treatments. In conclusion, our findings demonstrate that in vitro generated Langerhans-like cells can be used as a model of disease. Moreover, JAK-STAT inhibition may become a valuable new approach for the treatment of AA.

Diagnosis and Management of Alopecia Areata: A Saudi Expert Consensus Statement (2023)

Alopecia areata (AA) is a complex autoimmune disease manifesting as a chronic inflammatory disease characterized by non-scarring patches of hair loss over the face, scalp, and body. Several treatments have been proposed for AA, but none are curative nor achieve a state of remission. The present consensus statement aims to present the evidence- and experience-based recommendations on the diagnosis and management of AA in Saudi Arabia. The Ministry of Health in Saudi Arabia has opted to initiate a meeting of a multidisciplinary group to discuss and concede on this topic. Eight dermatology experts and clinical pharmacists convened in eight consensus meetings. All content presented in this document was agreed upon by this working group, including diagnosis and severity assessment, prognostic indicators, and therapeutic options for AA. Special consideration was given to special patient populations including pediatric patients and patients with less frequent presentations of AA. Updates of the current recommendations will take place as new evidence evolves in the treatment of AA.

Efficacy and safety of baricitinib in patients with alopecia areata: evidence to date

Alopecia areata (AA) is a chronic, tissue-specific autoimmune disorder, characterized by non-scaring hair loss, with a global prevalence of approximately 2%. Typically, it affects a young population, with initial onset frequently occurring before the age of 30 years. Even though the exact pathogenesis of AA remains unclear, the predominant hypothesis is the breakdown of immune privilege of the hair follicle, resulting in increased self-antigen and major histocompatibility complex expression in the follicular epithelium. The relapsing nature of the disease negatively impacts patients' quality of life and makes them more susceptible to developing psychiatric comorbidities. Although many treatment modalities have been proposed, there are no currently available treatments able to induce and sustain disease remission. Traditional treatment modalities, despite being widely used, present limited results and a high risk of adverse effects. Hence, there exists an unfulfilled requirement for treatments that are both more efficient and safer. The latest understanding of the pathophysiology of AA and its connection to the JAK-STAT pathway has prompted the advancement of JAK inhibitors. These small-molecule agents function by obstructing the JAK-STAT intracellular signalling pathway. Baricitinib an orally administered, selective JAK1 and JAK2 inhibitor is a promising alternative to the available treatments, and is already approved for the treatment of AA.

The relative efficacy of monotherapy with Janus kinase inhibitors, dupilumab and apremilast in adults with alopecia areata: Network meta-analyses of clinical trials

BACKGROUND

Janus kinase (JAK) inhibitors, biologics, and phosphodiesterase-4 (PDE-4) inhibitors are recent therapies for alopecia areata (AA)-albeit, knowledge gaps exist for these agents' relative efficacy.

OBJECTIVES

We determined the relative efficacy and safety of monotherapy with the aforementioned agents in adults with AA.

METHODS

The literature was systematically searched; we used data from randomized trials that investigated the agents' efficacy-as per Severity of Alopecia Tool (SALT) scores. Bayesian network meta-analyses were used to determine relative efficacy and safety. Effect modification was determined using a generalized linear model on aggregate data; evidence quality was evaluated.

RESULTS

Based on the surface under the cumulative ranking curve estimates obtained from multiple efficacy endpoints, regimens with the highest likelihood of achieving percent reduction in SALT scores, as well as a minimum 90%, 75% or 50% reduction in SALT scores are (in alphabetical order) baricitinib 4 mg once daily (QD), brepocitinib 60/30 mg QD, deuruxolitinib (CTP-543) 12 mg twice daily (BID), ritlecitinib 200/50 mg QD, ruxolitinib 20 mg BID and tofacitinib 5 mg BID. In contrast, dupilumab subcutaneous injections administered weekly and apremilast 30 mg BID were less likely to be effective. Discontinuation due to any adverse event was the least likely with oral JAK inhibitors, and more likely with dupilumab and apremilast.

CONCLUSIONS

Our results support the conduct of high-quality comparative trials to determine whether JAK inhibitors are more effective and safer than PDE4 inhibitors.

Unveiling a Shared Precursor Condition for Acne Keloidalis Nuchae and Primary Cicatricial Alopecias

Purpose

Small observational studies suggest subclinical disease occurrence in the normal-appearing scalp zones of several primary cicatricial alopecias. To aid patient management, we began routinely evaluating the entire scalp of patients with acne keloidalis nuchae (AKN), including trichoscopy-guided biopsies.

Patients and Methods

This retrospective study evaluated 41 patients sequentially presenting with AKN at a single clinic between June and December 2022. Primary lesions and normal-appearing scalp in the superior parietal scalp at least 5 cm away from AKN-affected zones were clinically evaluated, and areas showing perifollicular erythema or scales/casts on trichoscopy were biopsied and histologically analyzed.

Results

Forty-one men with AKN, including 20 men of African descent, 17 Hispanic, and 4 European-descended Whites, were evaluated. All patients, including 22% with associated folliculitis decalvans, showed scalp-wide trichoscopy signs of perifollicular erythema or scaling in normal-appearing scalp areas. All patients showed histologic evidence of perifollicular infundibulo-isthmic lymphocytoplasmic infiltrates and fibrosis (PIILIF), with 96% showing Vellus or miniaturized hair absence. PIILIF was often clinically mistaken for seborrheic dermatitis (44-51%). All White patients had mild papular acne keloidalis nuchae lesions mistaken for seborrheic dermatitis.

Conclusion

PIILIF may be a precursor to a wide spectrum of primary cicatricial alopecias, including AKN and folliculitis decalvans. This finding carries implications for the early diagnosis and management of AKN and other primary cicatricial alopecias.

Functional interrogation of lymphocyte subsets in alopecia areata using single-cell RNA sequencing

Alopecia areata (AA) is among the most prevalent autoimmune diseases, but the development of innovative therapeutic strategies has lagged due to an incomplete understanding of the immunological underpinnings of disease. Here, we performed single-cell RNA sequencing (scRNAseq) of skin-infiltrating immune cells from the graft-induced C3H/HeJ mouse model of AA, coupled with antibody-based depletion to interrogate the functional role of specific cell types in AA in vivo. Since AA is predominantly T cell-mediated, we focused on dissecting lymphocyte function in AA. Both our scRNAseq and functional studies established CD8+ T cells as the primary disease-driving cell type in AA. Only the depletion of CD8+ T cells, but not CD4+ T cells, NK, B, or γδ T cells, was sufficient to prevent and reverse AA. Selective depletion of regulatory T cells (Treg) showed that Treg are protective against AA in C3H/HeJ mice, suggesting that failure of Treg-mediated immunosuppression is not a major disease mechanism in AA. Focused analyses of CD8+ T cells revealed five subsets, whose heterogeneity is defined by an "effectorness gradient" of interrelated transcriptional states that culminate in increased effector function and tissue residency. scRNAseq of human AA skin showed that CD8+ T cells in human AA follow a similar trajectory, underscoring that shared mechanisms drive disease in both murine and human AA. Our study represents a comprehensive, systematic interrogation of lymphocyte heterogeneity in AA and uncovers a novel framework for AA-associated CD8+ T cells with implications for the design of future therapeutics.

Which is the Ideal JAK Inhibitor for Alopecia Areata - Baricitinib, Tofacitinib, Ritlecitinib or Ifidancitinib - Revisiting the Immunomechanisms of the JAK Pathway

Alopecia areata (AA) is an immune-mediated condition, clinically manifesting as non-cicatricial patches of alopecia. It is often a self-limiting condition; however, regrowth of hair can take a long period of time, resulting in significant psychological comorbidity. With the recent advances in pathomechanisms of AA, the therapeutic approach to the condition has become more specific, and targeted therapy with small molecules is probably the ideal intervention. Many therapies exist for AA, but none of the systemic agents were approved, until recently, when baricitinib (Janus kinase (JAK1 and JAK2 inhibitor) gained FDA approval for the treatment of adult patients with severe AA. JAK inhibitors (JAKibs) target the γc cytokine and interferon-gamma (IFN-γ) signaling pathway, which is critical to the immunopathogenesis of AA and thus can reverse the hair loss in AA. Although JAKibs are emerging as a promising treatment modality for AA, the ideal JAKib is not yet settled, as there is scant data on H-2-H (head-to-head) comparisons of JAK inhibitors in AA. Moreover, the response achieved with JAKibs is not sustained after treatment discontinuation, with many studies showing a high recurrence rate with tofacitinib and ruxolitinib post-treatment. Also, recent studies have hypothesized that JAK2, with its ubiquitous expression, can cause adverse effects, unlike JAK1, which is associated with multiple major cytokine receptor families and JAK3, which is exclusively associated with the γc cytokine receptor. Thus, JAK3ibs may be associated with a better side effect profile and, in conjunction with their specificity, may replace other JAKibs as the treatment of choice for AA. We herein discuss the role of the JAK/STAT (signal transducer and activator of transcription) pathway in AA, the intricacies of various JAKibs in the management of AA, and emphasize the need for studies on tissue JAK and cytokine expression before arriving at the ideal JAKibs for AA.

Clinical and Genetic Aspects of Alopecia Areata: A Cutting Edge Review

Alopecia areata (AA) is a chronic, non-scarring, immune-mediated skin disease that affects approximately 0.5-2% of the global population. The etiology of AA is complex and involves genetic and environmental factors, with significant advancements in genetic research occurring in recent years. In addition to well-known genes such as PTPN22, CTLA4, and IL2, which have been widely supported as being associated with AA, an increasing number of specific gene-related loci have been discovered through advances in genetic research. For instance, gene analysis of microRNAs can reveal the critical role of miRNAs in regulating gene expression, aiding in the understanding of cellular and organismal functional regulatory mechanisms. Furthermore, numerous studies have confirmed the existence of correlations between AA and other immune-related diseases. Examples include hyperthyroidism and rheumatoid arthritis. By understanding the interrelationships between AA and other immune diseases, we can further comprehend potential shared genetic foundations or pathogenic mechanisms among different diseases. Genetic research plays a crucial role in unraveling the pathogenesis of AA, as the identification of genetic variations associated with AA can assist in formulating more effective and targeted treatment strategies.

The evaluation of JAK inhibitors on effect and safety in alopecia areata: a systematic review and meta-analysis of 2018 patients

Background

JAK inhibitors treat various autoimmune diseases, but an updated systematic review in treating alopecia areata is currently lacking.

Objective

Evaluate the specific efficacy and safety of JAK inhibitors in alopecia areata by systematic review and meta-analysis.

Methods

Eligible studies in PubMed, Embase, Web of Science, and Clinical Trials up to May 30, 2022, were searched. We enrolled in randomized controlled trials and observational studies of applying JAK inhibitors in alopecia areata.

Results

6 randomized controlled trials with 1455 patients exhibited SALT₅₀ (odd ratio [OR], 5.08; 95% confidence interval [CI], 3.49-7.38), SALT₉₀ (OR, 7.40; 95% CI, 4.34-12.67) and change in SALT score (weighted mean difference [WSD], 5.55; 95% CI, 2.60-8.50) compared to the placebo. The proportion of 26 observational studies with 563 patients of SALT₅ was 0.71(95% CI, 0.65-0.78), SALT₅₀ was 0.54(95% CI 0.46-0.63), SALT₉₀ was 0.33(95% CI, 0.24-0.42), and SALT score (WSD, -2.18; 95% CI, -3.12 to -1.23) compared with baseline. Any adverse effects occurred in 921 of 1508 patients; a total of 30 patients discontinued the trial owing to adverse reactions.

Limitations

Few randomized controlled trials met the inclusion criteria and insufficiency of eligible data.

Conclusion

JAK inhibitors are effective in alopecia areata, although associated with an increased risk.

Selective Janus kinase 1 inhibition resolves inflammation and restores hair growth offering a viable treatment option for alopecia areata

Background

Janus Kinase (JAK) inhibition has recently demonstrated therapeutic efficacy in both restoring hair growth and resolving inflammation in Alopecia Areata (AA). These effects are dose dependent and mainly efficacious at ranges close to a questionable risk profile.

Objectives

We explored the possibility to separate the beneficial and adverse effects of JAK inhibition by selectively inhibiting JAK1 and thereby avoiding side effects associated with JAK2 blockade.

Methods

The C3H/HeJ mouse model of AA was used to demonstrate therapeutic efficacy in vivo with different regimens of a selection of JAK inhibitors in regards to systemic versus local drug exposure. Human peripheral blood lymphocytes were stimulated in vitro to demonstrate translation to the human situation.

Results

We demonstrate that selective inhibition of JAK1 produces fast resolution of inflammation and complete restoration of hair growth in the C3H/HeJ mouse model of AA. Furthermore, we show that topical treatment does not restore hair growth and that treatment needs to be extended well beyond that of restored hair growth in order to reach treatment-free remission. For translatability to human disease, we show that cytokines involved in AA pathogenesis are similarly inhibited by selective JAK1 and pan-JAK inhibition in stimulated human peripheral lymphocytes and specifically in CD8+ T cells.

Conclusion

This study demonstrates that systemic exposure is required for efficacy in AA and we propose that a selective JAK1 inhibitor will offer a treatment option with a superior safety profile to pan-JAK inhibitors for these patients.

Prescription Pattern of Tofacitinib for Alopecia Areata Among the Dermatologists in Saudi Arabia: A Cross-Sectional Study

Introduction Alopecia areata (AA) is a complex autoimmune condition that causes nonscarring hair loss. In Saudi Arabia, AA accounts for 1-2% of new dermatological outpatient visits. It typically presents with sharply demarcated round patches of hair loss and may present at any age. Traditional medical therapies include corticosteroids and immunotherapy. Choosing the ideal treatment depends on multiple factors such as patient age, disease severity, efficacy, side effects, and remission rate. Recent medications that have been used for treating AA are Janus kinase inhibitors. Aim The aim of the study is to assess the awareness and attitude of dermatologists and their use of Tofacitinib in treating AA. Method A cross-sectional study was conducted in 2019 across 14 major cities in Saudi Arabia. A self-administered online questionnaire was specifically developed and used. Dermatologists from government hospitals and private clinics were included through non-probability convenience sampling. The collected data was entered into Microsoft Excel and analyzed using SPSS program version 24. Results In total, out of 546 Dermatologists across Saudi Arabia who responded to the questionnaire, 127 (23.2%) physicians prescribed Tofacitinib in their practice. Out of those who prescribed the drug for AA cases, 58 dermatologists (45.6%) prescribed Tofacitinib after the failure of steroid injections. Among the 127 dermatologists who have utilized Tofacitinib in their practice, 92 (72.4%) believe that Tofacitinib is effective in treating AA. Almost 200 (47.7%) Dermatologists who never prescribed Tofacitinib reported that the main reason was due to the unavailability of the drug in the clinic they were practicing. Conclusions To conclude, out of 546 dermatologists working in Saudi Arabia, 127 (23.2%) prescribe Tofacitinib to treat AA. Ninety-two (72.4%) of the participants reported the effectiveness of Tofacitinib. Two hundred (47.7%) dermatologists who never prescribe Tofacitinib reported that the main reason was due to the unavailability. However, this would raise the need for more research regarding JAK inhibitors generally and Tofacitinib specifically, focusing on the effectiveness versus the side effects of Tofacitinib.

Baricitinib for the Treatment of Alopecia Areata

Alopecia areata (AA) is a relapsing, chronic, immune-mediated disease characterized by nonscarring, inflammatory hair loss that can affect any hair-bearing site. AA clinical presentation is heterogeneous. Its pathogenesis involves immune and genetic factors and several pro-inflammatory cytokines involved in AA pathogenesis, including interleukin-15 and interferon-γ, as well as Th2 cytokines, such as IL-4/IL-13, that signal through Janus kinase (JAK) pathway. AA treatment aims to stop its progression and reverse hair loss, and JAK inhibition has been shown to stop hair loss and reverse alopecia and has exhibited promising results in treating AA in clinical trials. Baricitinib, an oral, reversible, selective JAK1/JAK2 inhibitor, was shown to be superior to placebo on hair growth after 36 weeks of treatment in adults with severe AA in a phase 2 trial and recently in two phase 3 trials (BRAVE-AA1 and BRAVE-AA2). In both studies, the most common adverse events were upper respiratory tract infections, urinary tract infection, acne, headache, and elevated creatine kinase levels. On the basis of these trial results, baricitinib was recently approved by the European Medicines Agency (EMA) and US Food and Drug Administration (FDA) for the treatment of adults with severe AA. Nevertheless, longer trials are needed to determine the long-term efficacy and safety of baricitinib in AA. Current trials are ongoing and are planned to remain randomized and blinded for up to 200 weeks.

Discovery of C-5 Pyrazole-Substituted Pyrrolopyridine Derivatives as Potent and Selective Inhibitors for Janus Kinase 1

Developing selective inhibitors for Janus kinase 1 (JAK1) is a significant focus for improving the efficacy and alleviating the adverse effects in treating immune-inflammatory diseases. Herein, we report the discovery of a series of C-5 pyrazole-modified pyrrolopyrimidine derivatives as JAK1-selective inhibitors. The potential hydrogen bond between the pyrazole group and E966 in JAK1 is the key point that enhances JAK1 selectivity. These compounds exhibit 10- to 20-fold JAK1 selectivity over JAK2 in enzyme assays. Compound 12b also exhibits excellent JAK1 selectivity in Ba/F3-TEL-JAK cellular assays. Metabolism studies and the results of the hair growth model in mice indicate that compound 12b may be a viable lead compound for the development of highly JAK1-selective inhibitors for immune and inflammatory diseases.

Safety of Janus Kinase inhibitors in Patients with Alopecia Areata: A Systematic Review

BACKGROUND AND OBJECTIVES

Janus kinase (JAK) inhibitors are emerging as a therapeutic option for alopecia areata. The risk of potential adverse events is currently debated. In particular, several safety data for JAK inhibitors are extrapolated from a single study in elderly patients with rheumatoid arthritis treated with tofacitinib or adalimumab/etanercept as a comparator. The population of patients with alopecia areata is clinically and immunologically different from persons with rheumatoid arthritis and tumor necrosis factor (TNF) inhibitors are not effective in these patients. The objective of this systematic review was to analyze available data on the safety of various JAK inhibitors in patients with alopecia areata.

METHODS

The systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A literature review was performed by searching PubMed, Scopus and EBSCO databases with the last search on March 13, 2023.

RESULTS

In total, 36 studies were included. The frequency and odds ratio (OR) for most common adverse events versus placebo were: for baricitinib hypercholesterolemia (18.2% vs 10.5%, OR = 1.9) and headache (6.1% vs 5.1%, OR = 1.2), for brepocitinib elevated creatinine level (27.7% vs 4.3%, OR = 8.6) and acne (10.6% vs 4.3%, OR = 2.7), for ritlecitinib acne (10.4% vs 4.3%, OR = 2.6) and headache (12.5% vs 10.6%, OR = 1.2) and for deuruxolitinib headache (21.4% vs 9.1%, OR = 2.7) and acne (13.6% vs 4.5%, OR = 3.3). The respective numbers for upper respiratory infections were: baricitinib (7.3% vs 7.0%, OR = 1.0) and brepocitinib (23.4% vs 10.6%, OR = 2.6); for nasopharyngitis: ritlecitinib (12.5% vs 12.8%, OR = 1.0) and deuruxolitinib (14.6% vs 2.3%, OR = 7.3).

CONCLUSIONS

The most common side effects of JAK inhibitors in patients with alopecia areata were headache and acne. The OR for upper respiratory tract infections varied from over 7-fold increased to comparable to placebo. The risk of serious adverse events was not increased.

Efficacy and safety of ritlecitinib in adults and adolescents with alopecia areata: a randomised, double-blind, multicentre, phase 2b-3 trial

BACKGROUND

Alopecia areata is characterised by non-scarring loss of scalp, face, or body hair. We investigated the efficacy and safety of ritlecitinib, an oral, selective dual JAK3/TEC family kinase inhibitor, in patients with alopecia areata.

METHODS

In this randomised, double-blind, multicentre, phase 2b-3 trial done at 118 sites in 18 countries, patients aged 12 years and older with alopecia areata and at least 50% scalp hair loss were randomly assigned to oral ritlecitinib or placebo once-daily for 24 weeks, with or without a 4-week loading dose (50 mg, 30 mg, 10 mg, 200 mg loading dose followed by 50 mg, or 200 mg loading dose followed by 30 mg), followed by a 24-week extension period during which ritlecitinib groups continued their assigned doses and patients initially assigned to placebo switched to ritlecitinib 50 mg or 200 mg loading dose followed by 50 mg. Randomisation was done by use of an interactive response system and was stratified by baseline disease severity and age. The sponsor, patients, and investigators were masked to treatment, and all patients received the same number of tablets to maintain masking. The primary endpoint was Severity of Alopecia Tool (SALT) score 20 or less at week 24. The primary endpoint was assessed in all assigned patients, regardless of whether they received treatment. This study was registered with ClinicalTrials.gov, NCT03732807.

FINDINGS

Between Dec 3, 2018, and June 24, 2021, 1097 patients were screened and 718 were randomly assigned to receive ritlecitinib 200 mg + 50 mg (n=132), 200 mg + 30 mg (n=130), 50 mg (n=130), 30 mg (n=132), 10 mg (n=63), placebo to 50 mg (n=66), or placebo to 200 mg + 50 mg (n=65). 446 (62%) of 718 patients were female and 272 (38%) were male. 488 (68%) were White, 186 (26%) were Asian, and 27 (4%) were Black or African American. Of 718 patients randomly assigned, 104 patients discontinued treatment (34 withdrew, 19 adverse events [AEs], 12 physician decision, 12 lack of efficacy, 13 lost to follow up, five rolled over to long-term study transfer, four pregnancies, two protocol deviations, one declined to attend follow-up due to COVID-19, one attended last visit very late due to COVID-19, and one non-compliance). At week 24, 38 (31%) of 124 patients in the ritlecitinib 200 mg + 50 mg group, 27 (22%) of 121 patients in the 200 mg + 30 mg group, 29 (23%) of 124 patients in the 50 mg group, 17 (14%) of 119 patients in the 30 mg group, and two (2%) of 130 patients in the placebo group had a response based on SALT score 20 or less. The difference in response rate based on SALT score 20 or less between the placebo and the ritlecitinib 200 mg + 50 mg group was 29·1% (95% CI 21·2-37·9; p<0·0001), 20·8% (13·7-29·2; p<0·0001) for the 200 mg + 30 mg group, 21·9% (14·7-30·2; p<0·0001) for the 50 mg group, and 12·8% (6·7-20·4; p=0·0002) for the 30 mg group. Up to week 48 and including the follow-up period, AEs had been reported in 108 (82%) of 131 patients in the ritlecitinib 200 mg + 50 mg group, 105 (81%) of 129 patients in the 200 mg + 30 mg group, 110 (85%) of 130 patients in the 50 mg group, 106 (80%) of 132 patients in the 30 mg group, 47 (76%) of 62 patients in the 10 mg group, 54 (83%) of 65 patients placebo to ritlecitinib 200 mg + 50 mg in the extension period, and 57 (86%) of 66 patients in the placebo to 50 mg group. The incidence of each AE was similar between groups, and there were no deaths.

INTERPRETATION

Ritlecitinib was effective and well tolerated in patients aged 12 years and older with alopecia areata. Ritlecitinib might be a suitable treatment option for alopecia areata in patients who are candidates for systemic therapy.

FUNDING

Pfizer.

Systematic review of newer agents for the management of alopecia areata in adults: Janus kinase inhibitors, biologics and phosphodiesterase-4 inhibitors

Management options for moderate-to-severe alopecia areata (AA) are limited owing to a lack of safe and effective treatments suitable for long-term use. However, newer agents have the potential to induce and maintain hair regrowth in patients with a better side-effects profile compared to systemic steroids or conventional systemic agents. In this article, we conducted a systematic review of newer agents, including Janus kinase (JAK) inhibitors, biologics and phosphodiesterase-4 (PDE-4) inhibitors, for the treatment of AA in adult patients evaluated in randomized controlled trials (RCTs) using the Severity of Alopecia Tool score. A literature search was performed on PubMed and ClinicalTrials.gov, which identified 106 items with 12 RCTs eligible for review. Information regarding the treatment regimen, duration, endpoints, efficacy and adverse events were extracted; product monograph information was also summarized for approved agents with or without indications for AA. Overall, current data suggest the oral JAK inhibitors (baricitinib, ritlecitinib, deuruxolitinib, brepocitinib) as a promising new class of agents that can induce significant hair regrowth, with mild to moderate adverse effects. Baricitinib recently received US FDA approval for the treatment of severe AA, while ritlecitinib and deuruxolitinib have received the breakthrough therapy designation for AA. In contrast, PDE-4 inhibitors (apremilast) and the biologics (dupilumab, secukinumab and aldesleukin) appear to have limited efficacy thus far. Results from ongoing and future long-term studies could shed light on the utility of the newer agents in altering the progression of AA.

Recent advances in the genetics of alopecia areata

Alopecia areata (AA) is a common autoimmune-mediated hair loss disorder in humans with an estimated lifetime risk of approximately 2 %. Episodes of hair loss usually begin with isolated hairless patches that may progress to complete hair loss over the entire body. A familial occurrence of AA is well established, with recurrence risks of about 6-8 % in first-degree relatives. AA is a multifactorial disorder involving both environmental and genetic risk factors. Previous research has identified 14 susceptibility loci, most of which implicate genes involved in the immune response. The following review presents a summary of the latest findings from genome-wide association, sequencing and gene expression studies of AA, as well as their contribution to the recent therapeutic developments.

A phase 2a randomized vehicle-controlled multi-center study of the safety and efficacy of delgocitinib in subjects with moderate-to-severe alopecia areata

Alopecia areata/AA is an autoimmune cause of nonscarring hair loss. The pathogenesis of AA involves many immune axes, including Th1/Th2 pathways. Delgocitinib is a pan-Janus kinase/JAK inhibitor that broadly blocks pro-inflammatory cytokines and has been effective in other inflammatory skin conditions. Recent human studies/reports have shown that use of some systemic JAK inhibitors led to hair regrowth, suggesting this medication class as a potential therapy for AA. However, topical treatment is desirable due to potential systemic side effects. To assess the efficacy and safety of topical delgocitinib in AA, we conducted a double-blind, randomized, vehicle-controlled clinical trial in 31 moderate-to-severe AA patients that were randomized 2:1 to receive delgocitinib ointment 30 mg/g (n = 20) or ointment vehicle (n = 11) for 12 weeks. The primary endpoint was change in severity of Alopecia Tool/SALT score from baseline to week 12. The secondary endpoint included safety profile by reported adverse events. Twenty-three subjects completed the trial, with eight discontinuing mostly due to voluntary withdrawal. Ten patients receiving delgocitinib ointment and three patients receiving vehicle showed SALT score improvements after 12 weeks, but the mean percent SALT improvement at week 12 compared to baseline between the two arms was not significant (p = 0.92). Our study suggests that delgocitinib ointment is not effective in moderate-to-severe AA, likely due to its inability to penetrate sufficiently deeply into the dermis of the scalp, but larger studies are necessary to assess whether a different formulation of topical JAK inhibitors may be suitable to treat mild or more localized forms of AA.

Janus Kinase Inhibitors in the Treatment of Alopecia Areata

Alopecia areata is a disease of autoimmune origin which causes non scarring hair loss. The extent of alopecia varies from a small patch to complete scalp and body hair loss, which can have huge psychosocial impact for those affected. Treatment modalities which have been used so far included nonspecific immunosuppressive medications, such as corticosteroids, cyclosporine, and methotrexate, or topical immunomodulators, such as diphencyprone, dithranol, and squaric acid dibutylester. The recognition of the importance of Janus kinase pathway in alopecia areata pathogenesis enabled more specific approaches in treatment. Positive outcomes of Janus kinase inhibitors in several trials granted approval for baricitinib which became the first on-label treatment for alopecia areata. The aim of this review is to summarize the role, efficacy and safety of several Janus kinase inhibitors in alopecia areata.

Effectiveness and safety of baricitinib in patients with alopecia areata: a systematic review and Meta-analysis of randomized controlled trials

BACKGROUND

Since there is now no medication available that has been approved by the US Food and Drug Administration, alopecia areata (AA) is an autoimmune condition that has a detrimental impact on individuals. Recent clinical trials using baricitinib demonstrated that it may be effective in treating AA. This meta-analysis was done to evaluate the effectiveness and safety of baricitinib in comparison to placebo.

METHODS

Author looked through Scopus, Web of Science, Cochrane Library, PubMed, for all published, randomized, clinical trials.

RESULTS

This meta-analysis included 1282 participants from two citations (reporting three stand-alone studies). In term of SALT score, baricitinib significantly outperformed placebo; MD = -34.07, 95% CI [-37.90, -30.23], p < .00001. Additionally, the proportion of patients in the baricitinib group that attained SALT ≤ 20 was significantly higher than in the placebo group; RR = 6.41, 95% CI [4.57, 8.98], p < .00001. The results of the safety analysis revealed no significant differences between the baricitinib and placebo groups for any of the outcomes with the exception of acne, which was significantly higher in the placebo group when compared to the baricitinib group (RR= 4.79, 95% CI [2.38, 9.66], p .0001).

CONCLUSION

When compared to placebo, baricitinib is an effective and well-tolerated medication for the treatment of AA.

Comparative Efficacy and Safety of Janus Kinase Inhibitors Used in Alopecia Areata: A Systematic Review and Meta-analysis

The aim of this study was to compare the efficacy and safety of treatment with Janus kinase inhibitors for alopecia areata, measured by change in Severity of Alopecia Tool (SALT) score. A systematic review following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines was performed using Medline, EMBASE and Cochrane library. All studies investigating the efficacy of treatments for alopecia areata were included. Primary outcomes were the proportion of patients with alopecia areata achieving 30%, 50%, 75%, 90% and 100% improvement in SALT score after treatment with a Janus kinase inhibitor. A meta-analysis was performed including all randomized controlled trials investigating Janus kinase inhibitors. A total of 37 studies matched the inclusion criteria and were included. Meta-analysis was performed based on 5 randomized studies. Regarding patients with alopecia areata defined as ≥ 50% scalp hair loss, baricitinib 4 mg once daily demonstrated the highest efficacy. However, among patients with alopecia areata defined as a SALT score ≥ 50, oral deuruxolitinib 12 mg twice daily demonstrated the highest efficacy. Deuruxolitinib and baricitinib appear to be promising drugs for the treatment of alopecia areata. However, the response depends on the dosage of the drug. More randomized trials, with identical inclusion criteria and dose and duration of treatment, are required to confirm these findings.

JAK Inhibitors: A New Weapon in the Skin Care Providers' Arsenal

A number of chronic skin diseases, such as vitiligo and alopecia areata, are historically resistant to or respond poorly to treatment. Additionally, disorders such as atopic dermatitis and psoriasis have subtypes that are inadequately treated by current medications. Lastly, in the field of dermatology there are a number of conditions, some genetic (such as Darier's disease and Hailey-Hailey disease) and others caused by aberrant inflammatory responses (macrophage-driven conditions such as sarcoidosis and autoimmune conditions such as localized scleroderma) where effective treatments have been limited to date. A new class of anti-inflammatory medications that inhibit the Janus Kinase-Signal transducer and activator of transcription pathway (JAK-STAT) show great promise in providing new and effective treatment of these formerly recalcitrant conditions. This brief review will cover inhibitors of the JAK-STAT pathway (JAK inhibitors) currently approved for use in treating dermatologic diseases including several very recently approved medications. It will also touch on additional conditions under study or where early reports of efficacy are promising.

Alopecia Areata: Burden of Disease, Approach to Treatment, and Current Unmet Needs

Alopecia areata is an autoimmune hair loss disorder with variations in distribution, duration, and severity. The disease is chronic and often follows an unpredictable course, frequently leading to stress and anxiety for those who suffer from it. Throughout the years more knowledge has been gained regarding pathogenesis, diagnostic tools, impact on quality of life, as well as treatment strategies for alopecia areata. However, challenges in treating and alleviating the burden of disease remain. In this article, we discuss updates regarding the pathogenesis and treatment of alopecia areata and highlight unmet needs of the condition, including a review of limitations of current treatments, accessibility to management strategies, and the need for disease awareness and advocacy.

Real-world experience and long-term evaluation of tofacitinib in refractory alopecia areata: A prospective, open-label, single-center study in Asian Arab population

Tofacitinib is a pan-janus kinase inhibitor (JAK) which has been tested off-label in alopecia areata (AA) with promising results. However, evidence of tofacitinib in real-life setting is still poor. We evaluated long-term efficacy and safety of tofacitinib for refractory AA. This is a prospective, open-label, observational, single-center cohort study conducted between January 2018 and December 2020. Primary end-point was the percent change in Severity of Alopecia Tool (SALT) at the basal visit and at the most recent follow-up visit. Three categories of treatment response were analyzed. Data on 47 participants of Arab-Asian heritage were analyzed. A complete and partial regrowth was observed in 18 patients (41.86%) and 11 patients (25.58%), respectively. In 12 patients (27.9%), no response was obtained. Most of the non-responders belonged to the alopecia universalis group (66.67%). No statistical differences were observed in rates of regrowth between pediatric and adult individuals (p = 0.52), nor between women and men. Significant differences in the average duration of tofacitinib treatment were obtained among the three categories of regrowth (p < 0.003), notably duration of AA did not impact the clinical regrowth (p = 0.62). To the best of our knowledge, this is the first prospective, observational, long-term study using tofacitinib in refractory AA. Rates of regrowth and side effects are analogous to previous works. Length of tofacinitib therapy should last for 12 months before considering any discontinuation or change, since early cessation can lead to treatment failures or incomplete regrowth. Maintenance therapy after complete regrowth has demonstrated to be safe and effective to prevent recurrences of hair loss.

Efficacy and safety of JAK inhibitors in the treatment of alopecia areata in children: a systematic review and meta-analysis

BACKGROUND

Alopecia areata (AA) is a non-scarring hair loss mediated by T lymphocytes. Recently, a growing number of studies have shown that Janus kinase inhibitors are effective in the treatment of AA in children.

METHODS

A systematic review and meta-analysis were performed according to the PRISMA guidelines. Good response was defined as more than 50% decrease in Severity of Alopecia Tool (SALT) score or complete regrowth or more than 50% regrowth. Partial response was defined as 5-50% decrease in SALT score. Any response to treatment was defined as more than 5% in SALT score decrease.

RESULTS

There were 81.9% responders, 68.5% good responders, and 7.7% partial responders among the 10 included studies. The treatment duration was longer in good responders than in partial responders (p = .009). Oral route was linked to a better response to topical medication, with an odds ratio of 7.8 (95%CI 1.655-36.76). In terms of toxicity, reported adverse events included only mild symptoms. Liver transaminase elevation, upper respiratory tract infection, and eosinophilia were the most common adverse events.

CONCLUSIONS

Janus kinase inhibitors demonstrated promise in the treatment of AA in children, with the most common side effects being minor and reversible.

Induction of T cell exhaustion by JAK1/3 inhibition in the treatment of alopecia areata

Alopecia areata (AA) is an autoimmune disease caused by T cell-mediated destruction of the hair follicle (HF). Therefore, approaches that effectively disrupt pathogenic T cell responses are predicted to have therapeutic benefit for AA treatment. T cells rely on the duality of T cell receptor (TCR) and gamma chain (γc) cytokine signaling for their development, activation, and peripheral homeostasis. Ifidancitinib is a potent and selective next-generation JAK1/3 inhibitor predicted to disrupt γc cytokine signaling. We found that Ifidancitinib robustly induced hair regrowth in AA-affected C3H/HeJ mice when fed with Ifidancitinib in chow diets. Skin taken from Ifidancitinib-treated mice showed significantly decreased AA-associated inflammation. CD44⁺CD62L^- CD8⁺ T effector/memory cells, which are associated with the pathogenesis of AA, were significantly decreased in the peripheral lymphoid organs in Ifidancitinib-treated mice. We observed high expression of co-inhibitory receptors PD-1 on effector/memory CD8⁺ T cells, together with decreased IFN-γ production in Ifidancitinib-treated mice. Furthermore, we found that γc cytokines regulated T cell exhaustion. Taken together, our data indicate that selective induction of T cell exhaustion using a JAK inhibitor may offer a mechanistic explanation for the success of this treatment strategy in the reversal of autoimmune diseases such as AA.

Hair Follicle Melanocytes Initiate Autoimmunity in Alopecia Areata: a Trigger Point

Alopecia areata (AA) is characterized by common non-scarring alopecia due to autoimmune disorders. To date, the specific pathogenesis underlying AA remains unknown. Thus, AA treatment in the dermatological clinic is still a challenge. Numerous clinical observations and experimental studies have established that melanocytes may be the trigger point that causes hair follicles to be attacked by the immune system. A possible mechanism is that the impaired melanocytes, under oxidative stress, cannot be repaired in time and causes apoptosis. Melanocyte-associated autoantigens are released and presented, inducing CD8⁺ T cell attacks. Thereafter, amplification of the immune responses further spreads to the entire hair follicle (HF). The immune privilege of HF subsequently collapses, leading to AA. Herein, we present a narrative review on the roles of melanocytes in AA pathogenesis, aiming to provide a better understanding of this disease from the melanocyte's perspective.

An overview of JAK/STAT pathways and JAK inhibition in alopecia areata

Alopecia Areata (AA) is a common autoimmune disease characterized by non-scarring hair loss ranging from patches on the scalp to complete hair loss involving the entire body. Disease onset is hypothesized to follow the collapse of immune privilege of the hair follicle, which results in an increase in self-peptide/MHC expression along the follicular epithelium. Hair loss is associated with infiltration of the hair follicle with putatively self-reactive T cells. This process is thought to skew the hair follicle microenvironment away from a typically homeostatic immune state towards one of active inflammation. This imbalance is mediated in part by the dominating presence of specific cytokines. While interferon-γ (IFNγ) has been identified as the key player in AA pathogenesis, many other cytokines have also been shown to play pivotal roles. Mechanistic studies in animal models have highlighted the contribution of common gamma chain (γ_c) cytokines such as IL-2, IL-7, and IL-15 in augmenting disease. IFNγ and γ_c cytokines signal through pathways involving receptor activation of Janus kinases (JAKs) and signal transducers and activators of transcription (STATs). Based on these findings, JAK/STAT pathways have been targeted for the purposes of therapeutic intervention in the clinical setting. Case reports and series have described use of small molecule JAK inhibitors leading to hair regrowth among AA patients. Furthermore, emerging clinical trial results show great promise and position JAK inhibitors as a treatment strategy for patients with severe or recalcitrant disease. Demonstrated efficacy from large-scale clinical trials of the JAK inhibitor baricitinib led to the first-in-disease FDA-approved treatment for AA in June of 2022. This review aims to highlight the JAK/STAT signaling pathways of various cytokines involved in AA and how targeting those pathways may impact disease outcomes in both laboratory and clinical settings.

The efficacy and safety of JAK inhibitors for alopecia areata: A systematic review and meta-analysis of prospective studies

Background: Due to the lack of comprehensive evidence based on prospective studies, the efficacy and safety of Janus Kinase (JAK) inhibitors (including tofacitinib, ruxolitinib, baricitinib, ritlecitinib and brepocitinib) for alopecia areata (AA) are yet to be proved.

Methods: The systematic review and meta-analysis was performed pursuant to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guideline and registered on PROSPERO (CRD42022303007).

Results: Fourteen prospective studies (5 RCTs and 9 non-RCTs), enrolling a total of 1845 patients with AA, were included for quantitative analysis. In RCTs, oral JAK inhibitors resulted in higher good response rate compared with control (RR: 6.86, 95% CI: 2.91–16.16); topical JAK inhibitors did not show any difference compared with control (RR: 1.00, 95% CI: 0.31–3.18). In non-RCTs, the pooled rate of good response to oral, topical and sublingual JAK inhibitors were 63% (95% CI: 44%–80%), 28% (95% CI: 1%–72%) and 11% (95% CI: 1%–29%), respectively. The pooled recurrence rate in patients treated with JAK inhibitors was 54% (95% CI: 39%–69%), mainly due to the withdrawal of JAK inhibitors. In RCTs, no difference was found in the risk of experiencing most kind of adverse events; in non-RCTs, the reported adverse events with high incidence rate were mostly mild and manageable.

Conclusion: JAK inhibitors are efficacious and generally well-tolerated in treating AA with oral administration, whereas topical or sublingual administration lacks efficacy. Subgroup analyses indicate that baricitinib, ritlecitinib and brepocitinib seem to have equal efficacy for AA in RCTs; ruxolitinib (vs. tofacitinib) and AA (vs. AT/AU) are associated with better efficacy outcomes in non-RCT. Due to the high recurrence rate after withdrawal of JAK inhibitors, continuous treatment should be considered to maintain efficacy.

Systematic Review Registration: PROSPERO: CRD 42022303007

CHAC1 as a novel biomarker for distinguishing alopecia from other dermatological diseases and determining its severity

Alopecia Areata (AA) is characterised by an autoimmune response to hair follicles (HFs) and its exact pathobiology remains unclear. The current study aims to look into the molecular changes in the skin of AA patients as well as the potential underlying molecular mechanisms of AA in order to identify potential candidates for early detection and treatment of AA. We applied Weighted Gene Co-expression Network Analysis (WGCNA) to identify key modules, hub genes, and mRNA-miRNA regulatory networks associated with AA. Furthermore, Chi2 as a machine-learning algorithm was used to compute the gene importance in AA. Finally, drug-target construction revealed the potential of repositioning drugs for the treatment of AA. Our analysis using four AA data sets established a network strongly correlated to AA pathogenicity based on GZMA, OXCT2, HOXC13, KRT40, COMP, CHAC1, and KRT83 hub genes. Interestingly, machine learning introduced these genes as important in AA pathogenicity. Besides that, using another ten data sets, we showed that CHAC1 could clearly distinguish AA from similar clinical phenotypes, such as scarring alopecia due to psoriasis. Also, two FDA-approved drug candidates and 30 experimentally validated miRNAs were identified that affected the co-expression network. Using transcriptome analysis, suggested CHAC1 as a potential diagnostic predictor to diagnose AA.

Using qualitative methods to establish the clinically meaningful threshold for treatment success in alopecia areata

PURPOSE

Traditionally, appropriate anchors are used to investigate the amount of change on a clinician-reported outcome assessment that is meaningful to individual patients. However, novel qualitative methods involving input from disease state experts together with patients may better inform the individual improvement threshold for demonstrating the clinical benefit of new treatments. This study aimed to establish a clinically meaningful threshold for treatment success for the clinician-reported Severity of Alopecia Tool (SALT) score for patients with alopecia areata (AA).

METHODS

A purposive sample of 10 dermatologists expert in AA and 30 adult and adolescent patients with AA and a history of ≥ 50% scalp hair loss were recruited. Semi-structured interview questions explored the outcome that represented treatment success to clinicians and patients. Findings were analyzed using thematic methods to identify treatment success thresholds.

RESULTS

Both informant groups confirmed scalp hair amount as the outcome of priority. Most expert clinicians considered a static threshold of 80% (n = 5) or 75% (n = 3) of the scalp hair as a treatment success. Most patient responses ranged from 70 to 90% (median: 80% of the scalp hair). Subsequently, queried patients confirmed that achieving SALT score ≤ 20 with treatment would be a success, as reflected in the Alopecia Areata Investigator Global Assessment (AA-IGA™). The novel qualitative processes used to inform this meaningful threshold reflects a clinician-then-patient process for: (a) confirmation of the patient outcome of priority; and (b) clinician input on a preliminary treatment success level for independent understanding among patients.

CONCLUSION

This qualitative investigation of expert clinicians-then-patients with AA confirmed that achieving an amount of 80% or more scalp hair (SALT score ≤ 20) was an appropriate individual treatment success threshold indicating clinically meaningful improvement for patients with ≥ 50% scalp hair loss. A qualitative investigation of a quantifiable treatment success threshold is possible through a well-designed interview process with expert clinicians and the appropriate patient population.

Primary cicatricial alopecias are characterized by dysregulation of shared gene expression pathways

The primary forms of cicatricial (scarring) alopecia (PCA) are a group of inflammatory, irreversible hair loss disorders characterized by immune cell infiltrates targeting hair follicles (HFs). Lichen planopilaris (LPP), frontal fibrosing alopecia (FFA), and centrifugal cicatricial alopecia (CCCA) are among the main subtypes of PCAs. The pathogenesis of the different types of PCAs are poorly understood, and current treatment regimens yield inconsistent and unsatisfactory results. We performed high-throughput RNA-sequencing on scalp biopsies of a large cohort PCA patients to develop gene expression-based signatures, trained into machine-learning-based predictive models and pathways associated with dysregulated gene expression. We performed morphological and cytokine analysis to define the immune cell populations found in PCA subtypes. We identified a common PCA gene signature that was shared between LPP, FFA, and CCCA, which revealed a significant over-representation of mast cell (MC) genes, as well as downregulation of cholesterogenic pathways and upregulation of fibrosis and immune signaling genes. Immunohistological analyses revealed an increased presence of MCs in PCAs lesions. Our gene expression analyses revealed common pathways associated with PCAs, with a strong association with MCs. The indistinguishable differences in gene expression profiles and immune cell signatures between LPP, FFA, and CCCA suggest that similar treatment regimens may be effective in treating these irreversible forms of hair loss.

Translational impact of omics studies in alopecia areata: recent advances and future perspectives

INTRODUCTION

Alopecia areata (AA) is a non-scarring, hair loss disorder and a common autoimmune-mediated disease with an estimated lifetime risk of about 2%. To date, the treatment of AA is mainly based on suppression or stimulation of the immune response. Genomics and transcriptomics studies generated important insights into the underlying pathophysiology, enabled discovery of molecular disease signatures, which were used in some of the recent clinical trials to monitor drug response and substantiated the consideration of new therapeutic modalities for the treatment of AA such as abatacept, dupilumab, ustekinumab and Janus Kinase (JAK) inhibitors.

AREAS COVERED

In this review, genomics and transcriptomics studies in AA are discussed in detail with particular emphasis on their past and prospective translational impacts. Microbiome studies are also briefly introduced.

EXPERT OPINION

The generation of large datasets using the new high-throughput technologies has revolutionized medical research and AA has also benefited from the wave of omics studies. However, the limitations associated with JAK inhibitors and clinical heterogeneity in AA patients underscore the necessity for continuing omics research in AA for discovery of novel therapeutic modalities and development of clinical tools for precision medicine.

Unmet Medical Needs in Chronic, Non-communicable Inflammatory Skin Diseases

An estimated 20-25% of the population is affected by chronic, non-communicable inflammatory skin diseases. Chronic skin inflammation has many causes. Among the most frequent chronic inflammatory skin diseases are atopic dermatitis, psoriasis, urticaria, lichen planus, and hidradenitis suppurativa, driven by a complex interplay of genetics and environmental factors. Autoimmunity is another important cause of chronic skin inflammation. The autoimmune response may be mainly T cell driven, such as in alopecia areata or vitiligo, or B cell driven in chronic spontaneous urticaria, pemphigus and pemphigoid diseases. Rare causes of chronic skin inflammation are autoinflammatory diseases, or rheumatic diseases, such as cutaneous lupus erythematosus or dermatomyositis. Whilst we have seen a significant improvement in diagnosis and treatment, several challenges remain. Especially for rarer causes of chronic skin inflammation, early diagnosis is often missed because of low awareness and lack of diagnostics. Systemic immunosuppression is the treatment of choice for almost all of these diseases. Adverse events due to immunosuppression, insufficient therapeutic responses and relapses remain a challenge. For atopic dermatitis and psoriasis, a broad spectrum of innovative treatments has been developed. However, treatment responses cannot be predicted so far. Hence, development of (bio)markers allowing selection of specific medications for individual patients is needed. Given the encouraging developments during the past years, we envision that many of these challenges in the diagnosis and treatment of chronic inflammatory skin diseases will be thoroughly addressed in the future.

Refractory alopecia universalis associated with dermatomyositis successfully treated with tofacitinib

Dermatomyositis (DM) and alopecia areata are two diseases characterised by aberrant interferon signalling. While patchy alopecia of the scalp is a known feature of DM, alopecia universalis, which involves hair loss over the entire body, has rarely been reported in conjunction with DM. Herein, we report the case of a 30-year-old female with DM who developed refractory cutaneous disease and alopecia universalis that were successfully treated with tofacitinib. This could suggest that concomitant severe alopecia and refractory cutaneous DM may reflect a strong baseline interferon gene signature that may predict responsiveness to janus kinase inhibitors.

Two Phase 3 Trials of Baricitinib for Alopecia Areata

BACKGROUND

Alopecia areata is an autoimmune condition characterized by rapid hair loss in the scalp, eyebrows, and eyelashes, for which treatments are limited. Baricitinib, an oral, selective, reversible inhibitor of Janus kinases 1 and 2, may interrupt cytokine signaling implicated in the pathogenesis of alopecia areata.

METHODS

We conducted two randomized, placebo-controlled, phase 3 trials (BRAVE-AA1 and BRAVE-AA2) involving adults with severe alopecia areata with a Severity of Alopecia Tool (SALT) score of 50 or higher (range, 0 [no scalp hair loss] to 100 [complete scalp hair loss]). Patients were randomly assigned in a 3:2:2 ratio to receive once-daily baricitinib at a dose of 4 mg, baricitinib at a dose of 2 mg, or placebo. The primary outcome was a SALT score of 20 or less at week 36.

RESULTS

We enrolled 654 patients in the BRAVE-AA1 trial and 546 in the BRAVE-AA2 trial. The estimated percentage of patients with a SALT score of 20 or less at week 36 was 38.8% with 4-mg baricitinib, 22.8% with 2-mg baricitinib, and 6.2% with placebo in BRAVE-AA1 and 35.9%, 19.4%, and 3.3%, respectively, in BRAVE-AA2. In BRAVE-AA1, the difference between 4-mg baricitinib and placebo was 32.6 percentage points (95% confidence interval [CI], 25.6 to 39.5), and the difference between 2-mg baricitinib and placebo was 16.6 percentage points (95% CI, 9.5 to 23.8) (P<0.001 for each dose vs. placebo). In BRAVE-AA2, the corresponding values were 32.6 percentage points (95% CI, 25.6 to 39.6) and 16.1 percentage points (95% CI, 9.1 to 23.2) (P<0.001 for each dose vs. placebo). Secondary outcomes for baricitinib at a dose of 4 mg but not at a dose of 2 mg generally favored baricitinib over placebo. Acne, elevated levels of creatine kinase, and increased levels of low- and high-density lipoprotein cholesterol were more common with baricitinib than with placebo.

CONCLUSIONS

In two phase 3 trials involving patients with severe alopecia areata, oral baricitinib was superior to placebo with respect to hair regrowth at 36 weeks. Longer trials are required to assess the efficacy and safety of baricitinib for alopecia areata. (Funded by Eli Lilly under license from Incyte; BRAVE-AA1 and BRAVE-AA2 ClinicalTrials.gov numbers, NCT03570749 and NCT03899259.).