Role of janus kinase inhibitors in the treatment of alopecia areata

Small molecule agents against alopecia: Potential targets and related pathways

Alopecia has emerged as a global concern, extending beyond the middle-aged and elderly population and increasingly affecting younger individuals. Despite its growing prevalence, the treatment options and effective drugs for alopecia remain limited due to the incomplete understanding of its underlying mechanisms. Therefore, it is urgent to explore the pathogenesis of alopecia and discover novel and safer therapeutic agents. This review provided an overview of the prevailing clinical disorders of alopecia, and the key pathways and targets involved in hair growth process. Additionally, it discusses FDA-approved drugs and clinical candidates for the treatment of alopecia, and explores small molecule compounds with anti-alopecia potential in the drug discovery phase. These endeavors are expected to provide researchers with valuable scientific insights and practical information for anti-alopecia drug discovery.

A phase 2a study investigating the effects of ritlecitinib on brainstem auditory evoked potentials and intraepidermal nerve fiber histology in adults with alopecia areata

Reversible axonal swelling and brainstem auditory evoked potential (BAEP) changes were observed in standard chronic (9-month) toxicology studies in dogs treated with ritlecitinib, an oral Janus kinase 3/tyrosine kinase expressed in hepatocellular carcinoma family kinase inhibitor, at exposures higher than the approved 50-mg human dose. To evaluate the clinical relevance of the dog toxicity finding, this phase 2a, double-blind study assessed BAEP changes and intraepidermal nerve fiber (IENF) histology in adults with alopecia areata treated with ritlecitinib. Patients were randomized to receive oral ritlecitinib 50 mg once daily (QD) with a 4-week loading dose of 200 mg QD or placebo for 9 months (placebo-controlled phase); they then entered the active-therapy extension and received ritlecitinib 50 mg QD (with a 4-week loading dose of 200 mg in patients switching from placebo). Among the 71 patients, no notable mean differences in change from baseline (CFB) in Waves I-V interwave latency (primary outcome) or Wave V amplitude on BAEP at a stimulus intensity of 80 dB nHL were observed in the ritlecitinib or placebo group at Month 9, with no notable differences in interwave latency or Wave V amplitude between groups. The CFB in mean or median IENF density and in percentage of IENFs with axonal swellings was minimal and similar between groups at Month 9. Ritlecitinib treatment was also not associated with an imbalanced incidence of neurological and audiological adverse events. These results provide evidence that the BAEP and axonal swelling finding in dogs are not clinically relevant in humans.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Deciphering the Complex Immunopathogenesis of Alopecia Areata

Alopecia areata (AA) is an autoimmune-mediated disorder in which the proximal hair follicle (HF) attack results in non-scarring partial to total scalp or body hair loss. Despite the growing knowledge about AA, its exact cause still needs to be understood. However, immunity and genetic factors are affirmed to be critical in AA development. While the genome-wide association studies proved the innate and acquired immunity involvement, AA mouse models implicated the IFN-γ- and cytotoxic CD8+ T-cell-mediated immune response as the main drivers of disease pathogenesis. The AA hair loss is caused by T-cell-mediated inflammation in the HF area, disturbing its function and disrupting the hair growth cycle without destroying the follicle. Thus, the loss of HF immune privilege, autoimmune HF destruction mediated by cytotoxic mechanisms, and the upregulation of inflammatory pathways play a crucial role. AA is associated with concurrent systemic and autoimmune disorders such as atopic dermatitis, vitiligo, psoriasis, and thyroiditis. Likewise, the patient's quality of life (QoL) is significantly impaired by morphologic disfigurement caused by the illness. The patients experience a negative impact on psychological well-being and self-esteem and may be more likely to suffer from psychiatric comorbidities. This manuscript aims to present the latest knowledge on the pathogenesis of AA, which involves genetic, epigenetic, immunological, and environmental factors, with a particular emphasis on immunopathogenesis.

Real-World Experience of Tofacitinib and Baricitinib Use in Alopecia Areata in Greek Population: A Retrospective Analysis With Focus on Safety

INTRODUCTION

The introduction of Janus Kinase inhibitors (JAKi) seems to revolutionize the field of alopecia areata (AA) therapeutics. However, real-world data are still missing.

OBJECTIVES

To provide evidence about effectiveness and safety of tofacitinib and baricitinib in AA in real-world settings and describe baseline disease characteristics and patients profiles that are considered good candidates for JAKi in the daily practice. Furthermore, we intended to investigate potential correlations between baseline characteristics and treatment outcomes.

METHODS

We retrospectively reviewed the databases of two tertiary Hospitals in Greece, to identify individuals of any age currently being treated with systemic JAKi for severe AA.

RESULTS

We identified 42 individuals, including 3 adolescents. In our cohort, 52.3% (22/42) were under tofacitinib and 47.6% (20/42) under baricitinib treatment. Efficacy analysis was performed on the subgroup of 30 patients that had completed at least a 3-month follow-up on treatment. In the latter group, mean time on treatment was 10 months. Mean Severity of Alopecia Tool and mean Dermatology Life Quality Index scores decreased from 84.46% and 12.86 at baseline, to 43.26% and 6.63, respectively. Complete response (CR) was recorded in 4 (13.33%), partial in 12 (40%) and no response in 14 patients (46.66%), correspondingly. Seventeen out of 42 (40.5%) individuals in total, reported at least 1 adverse event. No patient required hospitalization. Among 15 patients (35.7%) who got COVID-19, one suffered from serious infection. The 3 adolescents achieved CR with no significant adverse events.

CONCLUSIONS

Real-world data suggest efficacy and safety of JAKi in severe forms of AA. Tolerability is optimal in younger individuals.

Improvement of severe alopecia areata in an adolescent patient on upadacitinib

Recently, alopecia areata (AA) treatment via the Janus kinase (JAK)-signal transducer and activator of transcription pathway has been reported. However, as baricitinib, a JAK1/2 inhibitor is only approved for adult patients, children, and adolescent patients still lack treatment options. We present a case that showed improvement of severe AA in an adolescent patient on upadacitinib, which has been approved by the Food and Drug Administration (FDA) for use in patients with rheumatoid disease or atopic dermatitis (AD) in children aged 12 years or older and weighing 40 kg or more. Herein, we suggest that upadacitinib can be a good alternative for adolescent patients with AA, particularly those who may also have AD.

Synthesis and clinical application of new drugs approved by FDA in 2023

In 2023, the U.S. Food and Drug Administration (FDA) granted approval to a total of 55 new drugs, comprising 29 new chemical entities (NCEs) and 25 new biological entities (NBEs). These drugs primarily focus on oncology, the central nervous system, anti-infection, hematology, cardiovascular, ophthalmology, immunomodulatory and other therapeutic areas. Out of the 55 drugs, 33 (60 %) underwent an accelerated review process and received approval, while 25 (45 %) were specifically approved for the treatment of rare diseases. The purpose of this review is to provide an overview of the clinical uses and production techniques of 29 newly FDA-approved NCEs in 2023. Our intention is to offer a comprehensive understanding of the synthetic approaches employed in the creation of these drug molecules, with the aim of inspiring the development of novel, efficient, and applicable synthetic methodologies.

When to expect scalp hair regrowth during treatment of severe alopecia areata with baricitinib: insights from trajectories analyses of patients enrolled in two phase III trials

BACKGROUND

Baricitinib is approved for the treatment of adults with severe alopecia areata (AA). In the absence of robust data on the patterns of regrowth during treatment of severe AA, there is a gap in the knowledge regarding treatment expectations.

OBJECTIVES

To examine whether different clinical response subgroups could be identified in baricitinib-treated patients with severe AA and factors that contribute to these subgroups.

METHODS

The BRAVE-AA1 and BRAVE-AA2 phase III trials enrolled patients with severe AA [Severity of Alopecia Tool (SALT) score ≥ 50 (≥ 50% scalp hair loss)]. Patients randomized to baricitinib 4 mg or 2 mg retained their treatment allocation for 52 weeks. Based on patterns identified through growth mixture modelling (GMM), patients were categorized into responder subgroups according to when they first achieved ≥ 30% improvement from baseline in SALT score (SALT30). For each responder subgroup, trajectories of response (i.e. achievement of a SALT score ≤ 20, SALT score ≤ 10 and ≥ 50% change from baseline in SALT score) and baseline disease characteristics are reported.

RESULTS

Respectively, 515 and 340 patients were randomized to once-daily baricitinib 4 mg and 2 mg at baseline; 69% and 51%, respectively, achieved SALT30 at least once by week 52. Based on GMM findings, we identified three responder subgroups: early (SALT30 by week 12), gradual (SALT30 after week 12-week 36) and late (SALT30 after week 36-week 52). The proportions of early, gradual and late responders and nonresponders were, respectively, 33%, 28%, 8% and 31% among patients treated with baricitinib 4 mg, and 20%, 23%, 9% and 49%, respectively, among those treated with baricitinib 2 mg. Early responders had a shorter trajectory to maximal clinical outcomes (e.g. > 78% achieved a SALT score ≤ 20 by week 36) vs. gradual or late responders. Early responders were more frequent among patients with baseline severe AA (SALT score 50 to < 95) vs. very severe AA (SALT score 95-100). Overall, responders (early to late) were more frequent in patients with short (< 4 years) episodes of hair loss.

CONCLUSIONS

These analyses identified early, gradual and late responder subgroups for scalp hair regrowth in baricitinib-treated patients with severe AA, and that these subgroups are influenced by baseline characteristics. Findings from these analyses will help to inform treatment expectations for scalp hair regrowth.

Oral and Topical Administration of a Standardized Saw Palmetto Oil Reduces Hair Fall and Improves the Hair Growth in Androgenetic Alopecia Subjects - A 16-Week Randomized, Placebo-Controlled Study

Purpose

Androgenetic alopecia (AGA) is the most common type of hair loss in humans, affecting self-esteem and emotional well-being. This study aimed to assess the safety and efficacy of VISPOTM, a standardized saw palmetto oil (2-3% β-sitosterol), in subjects with mild-to-moderate AGA.

Methods

In a double-blind, placebo-controlled, four-arm clinical study, 80 healthy male and female subjects aged 18-50 years were randomly allocated (1:1:1:1) to receive either 400 mg capsules of VISPO or 5 mL of a topical formulation containing 20% VISPO or the respective placebo once daily for 16 weeks. The primary endpoints included hair count (hair comb and hair pull tests) and the self-assessment of perceived efficacy. Objective evaluation was performed using the global photographic assessment score. Hair density, thickness, and anagen/telogen ratio were evaluated using phototrichogram analysis.

Results

At the end of the study, oral and topical formulations of VISPO reduced hair fall by up to 29% (p<0.001) and 22.19% (p<0.01) from the baseline, respectively. Hair density increased by 5.17% and 7.61% in the oral and topical VISPO groups, respectively (p<0.001). In addition, oral ingestion of VISPO resulted in a marked reduction in serum dihydrotestosterone (DHT) levels in the subjects compared to placebo (p<0.001). However, the effect of the VISPO formulations on the anagen/telogen ratio was insignificant. No serious adverse effects were observed during the study.

Conclusion

VISPO formulations reduced hair fall and promoted hair regrowth and scalp appearance in AGA patients.

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.

Skin Homeostasis and Repair: A T Lymphocyte Perspective

Chronic, nonhealing wounds remain a clinical challenge and a significant burden for the healthcare system. Skin-resident and infiltrating T cells that recognize pathogens, microbiota, or self-antigens participate in wound healing. A precise balance between proinflammatory T cells and regulatory T cells is required for the stages of wound repair to proceed efficiently. When diseases such as diabetes disrupt the skin microenvironment, T cell activation and function are altered, and wound repair is hindered. Recent studies have used cutting-edge technology to further define the cellular makeup of the skin prior to and during tissue repair. In this review, we discuss key advances that highlight mechanisms used by T cell subsets to populate the epidermis and dermis, maintain skin homeostasis, and regulate wound repair. Advances in our understanding of how skin cells communicate in the skin pave the way for therapeutics that modulate regulatory versus effector functions to improve nonhealing wound treatment.

Hair Loss Profiles and Ritlecitinib Efficacy in Patients with Alopecia Areata: Post Hoc Analysis of the ALLEGRO Phase 2b/3 Study

INTRODUCTION

Ritlecitinib demonstrated efficacy in patients with alopecia areata (AA) in the ALLEGRO phase 2b/3 study (NCT03732807). However, hair loss presentation may vary based on location (e.g., scalp, eyebrow/eyelash, body). Here, we sought to identify distinct hair loss profiles at baseline and evaluate whether they affected the efficacy of ritlecitinib.

METHODS

Patients with AA aged ≥ 12 years with ≥ 50% scalp hair loss were randomized to daily ritlecitinib 10 mg (assessed for dose ranging only), 30 or 50 mg (± 4-week, 200-mg loading dose), or placebo for 24 weeks. Latent class analysis (LCA) identified hair loss profiles based on four baseline measurements: clinician-reported extent of scalp (Severity of Alopecia Tool score), eyebrow hair loss, eyelash hair loss, and patient-reported body hair loss. Logistic regression evaluated ritlecitinib (50 and 30 mg) efficacy vs placebo using Patient Global Impression of Change (PGI-C) and Patient Satisfaction with Hair Growth (P-Sat; amount, quality, and overall satisfaction) responses at Week 24, adjusting for key covariates, including latent class membership.

RESULTS

LCA identified five latent classes: (1) primarily non-alopecia totalis (AT; complete loss of scalp hair); (2) non-AT with moderate non-scalp involvement; (3) extensive scalp, eyebrow, and eyelash involvement; (4) AT with moderate non-scalp involvement; and (5) primarily alopecia universalis (complete scalp, face, and body hair loss). Adjusting for latent class membership, patients receiving ritlecitinib 30 or 50 mg were significantly more likely to achieve PGI-C response (30 mg: odds ratio, 8.62 [95% confidence interval, 4.42-18.08]; 50 mg: 12.29 [6.29-25.85]) and P-Sat quality of hair regrowth (30 mg: 6.71 [3.53-13.51]; 50 mg: 8.17 [4.30-16.46]) vs placebo at Week 24. Results were similar for P-Sat overall satisfaction and amount of hair regrowth.

CONCLUSION

Distinct and clinically relevant hair loss profiles were identified in ALLEGRO-2b/3 participants. Ritlecitinib was efficacious compared with placebo, independent of hair loss profile at baseline.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT03732807.

Treatment Patterns and Unmet Needs in the Management of Alopecia Areata: Results of a Physician's Survey in the Middle East

INTRODUCTION

Alopecia areata (AA) is an autoimmune disease characterized by nonscarring hair loss involving the scalp, face, and/or body. Literature on the prevalence, patient characteristics, management approaches, and challenges faced by patients with AA across the Middle East is limited. Therefore, a greater understanding of the current AA landscape within the region is needed. This cross-sectional study surveyed dermatologists from four countries to assess dermatologists' perspectives on the prevalence of AA within the Middle East, as well as patient characteristics, unmet needs, and management strategies.

METHODS

This blinded, quantitative, observational study surveyed practicing dermatologists in Egypt, Lebanon, Saudi Arabia, and the United Arab Emirates. The survey was conducted between September 2021 and January 2022 and comprised 47 closed-ended, multiple-choice questions as well as Likert scale responses. These questions assessed the characteristics of physicians and the patients in their practices, physicians' familiarity with treatment, and physicians' treatment approaches.

RESULTS

The estimated prevalence of AA varied across the region. Across all age groups treated for AA, the majority of patients had AA of mild severity (pediatric: 63%; adolescent: 60%; adult: 54%) and the scalp was reported as the most affected area (65%). Potent topical corticosteroids were the most frequently used treatment for mild to moderate and severe AA (92% and 78%, respectively). There was a lack of awareness of investigative treatments, with only 33% of dermatologists aware of these options. The greatest unmet needs in treating AA included long-term disease control, improved efficacy, faster onset of action, and better safety profiles (62%, 53%, 52%, and 51%, respectively).

CONCLUSIONS

This study provided insight into the diagnosis and management of AA in the Middle East. Treatment strategies were similar regardless of the severity of AA. Long-term disease control and improved efficacy and safety profiles were identified as key unmet needs in the treatment of AA.

Alopecia Areata Barbae in a Nutshell

Beard alopecia areata, or alopecia areata barbae, (BAA) is a subset of alopecia areata, a T-cell mediated inflammatory disease that disrupts the hair follicle cycle leading to early onset of catagen. The aim of this review is to help strengthen clinicians' skills in the evaluation, diagnosis, and management of BAA. We performed a literature review according to the modified PRISMA guidelines, using a combination of relevant key words in electronic databases. According to the data from the 25 articles on BAA reviewed here, BAA mostly affects middle-aged men (mean age 31 years) who typically experience patchy hair loss in the neck region, which spreads to the scalp within 12 months. Similar to AA, BAA is associated with autoimmune diseases such as H. pylori and thyroiditis; however, BAA has no clear genetic pattern of inheritance which is observed in alopecia areata. Common dermoscopic findings in BAA include vellus white hairs and exclamation mark hairs, which may help distinguish it from other pathologies affecting facial hair. In clinical trials, the ALBAS tool offers clinicians an objective metric to evaluate BAA severity. Until recently, topical steroids have been the mainstay therapy; however, topical and oral janus kinase inhibitors are achieving improved results, with up to 75% beard regrowth in an average of 12 months.

AIRE Deficiency Leads to the Development of Alopecia Areata‒Like Lesions in Mice

Alopecia areata (AA) is an autoimmune hair loss disorder with no cure. Patients with sequence variation in AIRE are 15 times more likely to develop AA than the general population, yet the roles of AIRE in AA pathogenesis are unknown. In this study, we report that 62% of C57BL/6J female Aire^‒/‒ mice spontaneously developed persistent AA-like lesions that displayed several hallmarks of human AA. Lesional Aire^‒/‒ skin exhibited hair follicle (HF) dystrophy as determined by a reduced number of anagen HFs, decreased anagen HF proliferation, hair pigmentary changes, and decreased hair width and length. Inflammatory infiltrate comprising CD8⁺ T cells, CD4⁺ T cells, CD68⁺ macrophages, and mast cells was prominent in lesional Aire^‒/‒ HFs. From gene expression analyses, we found lesional Aire^‒/‒ skin to have significantly increased expression of human AA signature genes, including H2-Ab1, Ifnγ, IFN-γ‒induced chemokines (Ccl5, Cxcl9‒11), γ_c family cytokine receptor Il2RA, and JAK‒signal transducer and activator of transcription (STAT) signaling components (Stat1, Stat2, Stat4). By immunostaining, lesional Aire^‒/‒ HFs also show upregulated major histocompatibility complex class I and downregulated α-melanocyte-stimulating hormone, signifying immune privilege collapse, and increased STAT1 activation in HF keratinocytes. Our study highlights a role for AIRE in HF biology and shows that Aire^‒/‒ mice may serve as a valuable model system to study AA pathogenesis.

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.

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.

An Updated Review on Current Treatment of Alopecia Areata and Newer Therapeutic Options

Alopecia areata (AA) is a dermatological disease that causes nonscarring hair loss. It can occur at any age and has an unpredictable and variable evolution in individuals. The aim of this review is to provide an update on the novel therapies currently being used, as well as upcoming therapeutic options in the treatment of AA.

Alopecia Areata: Case report and review of pathophysiology and treatment with Jak inhibitors

Alopecia Areata (AA) is a T-cell mediated autoimmune attack on hair follicles resulting in rapidly developing areas of hair loss involving the scalp and beard that can progress to total scalp hair loss (alopecia totalis) and loss of eyebrows, eyelashes, and total body hair (alopecia universalis). Affected patients have high rates of psychological disorders and decreased quality of life. There are no FDA approved treatments, and the available treatments have a high failure rate. JAK inhibitors are remarkably effective in many autoimmune diseases including Alopecia Areata. Presented is a case report of successful treatment with tofacitinib, and a literature review of the pathophysiology of alopecia areata, the mechanism of action of JAK inhibitors, and the JAK inhibitors in phase 2 and 3 trials.

Platelet-rich plasma in alopecia areata and primary cicatricial alopecias: A systematic review

Background

Immune-mediated alopecias (IMAs), a group of hair disorders associated with immunological reactions, remain a therapeutic challenge since available treatments are generally unfavorable with potential side effects. Platelet-rich plasma (PRP) has been recently proposed as a treatment option based on several limited-quality studies; however, there is no systematic evaluation of PRP efficacy on IMAs in the literature.

Objective

To assess PRP's effects in treating IMAs using a systematic review.

Methods

Electronic searches were conducted using PubMed, Embase, Scopus, and Cochrane Library databases. A search strategy was designed to retrieve all studies exploring PRP in treating IMAs, including alopecia areata (AA) and primary cicatricial alopecias (PCAs). In addition, all randomized and non-randomized studies reporting subjective and/or objective outcomes of alopecia treatment with PRP were included.

Results

Thirty-two studies were included, comprising 621 patients with AA and 19 patients with PCAs. PRP had superior efficacy as monotherapy in five studies, comparable to intralesional corticosteroids in six studies in AA treatment. In addition, in the analysis of PCAs, including lymphocytic and neutrophilic subtypes, PRP was efficacious in alleviating disease progression in nine studies.

Conclusion

PRP is considered a promising treatment for AA and PCAs in patients who experienced unfavorable outcomes from conventional treatment. However, its clinical application remains to be standardized, and its recommendation as a treatment for IMAs could not be ascertained due to a lack of high-quality evidence.

Systematic review registration

[https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=353859], identifier [CRD42022353859].

Safety and Efficacy of Ritlecitinib and Brepocitinib in Alopecia Areata: Results from the Crossover Open-Label Extension of the ALLEGRO Phase 2a Trial

The 24-week, double-blind period of the ALLEGRO phase 2a trial (NCT02974868) evaluated the safety and efficacy of ritlecitinib (Jak3/tyrosine kinase expressed in the hepatocellular carcinoma inhibitor) and brepocitinib (tyrosine kinase 2/Jak1 inhibitor) in patients with alopecia areata; patients could subsequently continue treatment in a 24-week single-blind extension, followed by a crossover open-label extension, described in this article. Patients who did not achieve ≥30% improvement from baseline in Severity of Alopecia Tool score at the end of the single-blind extension entered a 24-week crossover open-label extension: the ritlecitinib group switched to brepocitinib, and the brepocitinib group switched to ritlecitinib. Eighteen patients switched to brepocitinib, and five switched to ritlecitinib. Six treatment-emergent adverse events were reported by five patients; no new safety risks were observed after crossover. An exploratory efficacy evaluation showed that none of the five patients receiving ritlecitinib in the crossover open-label extension achieved ≥30% improvement from baseline in Severity of Alopecia Tool score or improvement in eyebrow/eyelash assessments. Four of 16 patients receiving brepocitinib achieved ≥30% improvement from baseline in Severity of Alopecia Tool score or better; 4 of 15 and 5 of 12 showed improvement in eyebrow and eyelash assessments, respectively. Although the small number of patients precludes firm conclusions regarding efficacy, the data suggest that some patients with alopecia areata and inadequate response to ritlecitinib after ≥24 weeks show benefit after switching to brepocitinib.

Alopecia areata - Current understanding and management

Alopecia areata (AA) is a chronic, immune-mediated disease characterized by acute or chronic non-scarring hair loss, with a heterogeneity in clinical manifestations ranging from patchy hair loss to complete scalp and body hair loss. An overview of the up-to-date pathophysiology and the underlying signaling pathways involved in AA together with diagnostic and therapeutic recommendations will be provided. Current treatments, including topical, systemic and injectable interventions show varying response and frequent relapses reflecting the unmet clinical need. Thus, the new emerging concepts and therapeutic approaches, including Janus kinase inhibitors are eagerly awaited. Traditional and emerging therapies of AA will be discussed, in order to provide physicians with guidance for AA management. Since the latter is so challenging and often tends to take a chronic course, it can have an enormous psychosocial burden on patients, compromising their quality of life and often causing depression and anxiety. Therefore, the psychosocial aspects of the disease need to be evaluated and addressed, in order to implement appropriate psychological support when needed.

Ritlecitinib: an investigational drug for the treatment of moderate to severe alopecia areata

INTRODUCTION

Alopecia areata (AA) is an inflammatory and autoimmune form of hair loss, which can present with one patch of hair loss, but in more extreme cases can lead to total body hair loss. There are limited therapeutic options and no cure, but medication can sometimes induce sustained remission. Disease control cannot be guaranteed; even those who regrow all hair on treatment can experience relapse. There are no FDA approved systemic treatments; therefore, an unmet need for safe, and effective treatments exists. Few treatments have been evaluated by randomized controlled trials. Case reports and series indicate oral Janus Kinase (JAK) inhibitors as a potential therapy. Ritlecitinib is a novel oral JAK3-selective inhibitor being investigated as an AA treatment.

AREAS COVERED

This article introduces ritlecitinib as treatment for AA and considers the mechanism of action, pharmacodynamics, pharmacokinetics, clinical efficacy, and safety [reporting data from a 24-week, phase 2a double-blinded placebo-controlled trial of ritlecitinib in patients with AA who have more than 50% scalp hair loss].

EXPERT OPINION

Ritlecitinib offers a novel mode of action, rapid onset, and the capacity for a superior safety profile over other JAK inhibitors. If approved, ritlecitinib will be widely prescribed by physicians overseeing the more severe AA patients for the foreseeable future. As JAK inhibitors regulate the hair growth cycle and have anti-inflammatory effects, the implementation of ritlecitinib in hair loss disorders other than AA, may prove beneficial.

Ritlecitinib and brepocitinib demonstrate significant improvement in scalp alopecia areata biomarkers

BACKGROUND

Janus kinase (JAK) inhibitors have shown encouraging results in the treatment of alopecia areata (AA), an autoimmune form of hair loss, in small, uncontrolled studies and case reports.

OBJECTIVE

We conducted a biopsy substudy during the randomized, double-blind, placebo-controlled first 24 weeks of a phase 2a clinical trial that evaluated the efficacy and safety of ritlecitinib, an inhibitor of JAK3 and the tyrosine kinase expressed in hepatocellular carcinoma (TEC) kinase family, and brepocitinib, an inhibitor of tyrosine kinase 2 (TYK2)/JAK1 in the treatment of AA.

METHODS

Change in biomarkers in lesional scalp biopsy samples between baseline and weeks 12 and 24 was an exploratory end point, and 46 patients participated from the ritlecitinib (n = 18), brepocitinib (n = 16), and placebo (n = 12) groups. Correlations of biomarkers with hair regrowth, measured using the Severity of Alopecia Tool (SALT) score, were also evaluated.

CLINICAL TRIAL REGISTRATION

NCT02974868.

RESULTS

At week 24, both ritlecitinib and brepocitinib demonstrated improvement exceeding 100% in the lesional scalp transcriptome toward a nonlesional profile. At week 12, the improvements in scalp tissue were greater with brepocitinib than ritlecitinib; however, at week 24, the improvements were greater with ritlecitinib.

CONCLUSIONS

For both ritlecitinib and brepocitinib, improvement in the SALT scores was positively associated with expression of T_H1 markers and negatively associated with expression of hair keratins. Larger, long-term clinical trials are warranted.

An integrated scalp and blood biomarker approach suggests the systemic nature of alopecia areata

BACKGROUND

Alopecia areata (AA) is characterized by immune dysregulation in both scalp and blood, but a large-scale approach establishing biomarkers of AA incorporating both scalp tissue and serum compartments is lacking. We aimed to characterize the transcriptomic signature of AA lesional and nonlesional scalp compared to healthy scalp and determine its relationship with the blood proteome in the same individuals, with comparative correlations to clinical AA disease severity.

METHODS

We evaluated lesional and nonlesional scalp tissues and serum from patients with moderate-to-severe AA (n = 18) and healthy individuals (n = 8). We assessed 33,118 genes in AA scalp tissue using RNAseq transcriptomic evaluation and 340 inflammatory proteins in serum using OLINK high-throughput proteomics. Univariate and multivariate approaches were used to correlate disease biomarkers with Severity of Alopecia Tool (SALT).

RESULTS

A total of 608 inflammatory genes were differentially expressed in lesional AA scalp (fold change/FCH>1.5, false discovery rate/FDR<0.05) including Th1 (IFNG/IL12B/CXCL11), Th2 (IL13/CCL18), and T-cell activation-related (ICOS) products. Th1/Th2-related markers were significantly correlated with AA clinical severity in lesional/nonlesional tissue, while keratins (KRT35/KRT83/KRT81) were significantly downregulated in lesional compared to healthy scalp (p < .05). Expression of cardiovascular/atherosclerosis-related markers (MMP9/CCL2/IL1RL1/IL33R/ST2/AGER) in lesional scalp correlated with their corresponding serum expression (p < .05). AA scalp demonstrated significantly greater biomarker dysregulation compared to blood. An integrated multivariate approach combining scalp and serum biomarkers improved correlations with disease severity/SALT.

CONCLUSION

This study contributes a unique understanding of the phenotype of moderate-to-severe AA with an integrated scalp and serum biomarker model suggesting the systemic nature of the disease, advocating for the need for immune-based systemic treatment.

Prevalence and Risk Factors Associated with the Occurrence of Autoimmune Diseases in Patients with Alopecia Areata

BACKGROUND

Increased rates of autoimmune diseases (ADs) have been reported in association with alopecia areata (AA); however, the risk factors for coexisting ADs in AA patients have been poorly investigated.

OBJECTIVE

To evaluate the prevalence and factors associated with AD comorbidities in patients with AA.

METHODS

This case-control study included patients diagnosed with AA between January 2000 and March 2020. Individuals with AA, both with and without concomitant ADs, were statistically compared. Variables significantly associated with coexisting ADs were identified using univariate and multivariate logistic regression analyses. Multinomial logistic regression analysis was performed to identify the specific risk factors for each concomitant AD.

RESULTS

Among the 615 patients with AA, comorbid ADs were found in 76 (12.4%). Autoimmune thyroid disease (AITD) exhibited the highest frequency (n = 42, 6.8%), followed by vitiligo (n = 15, 2.4%), and systemic lupus erythematosus (SLE) (n = 12, 2.0%). Logistic regression analyses revealed that female sex (odds ratio [OR] = 2.45, 95% confidence interval [CI] = 1.24-4.82; P = 0.011), nail abnormalities (OR = 2.49, 95% CI = 1.14-5.46; P = 0.023), and atopic diseases (OR = 1.98, 95% CI = 1.09-2.43; P < 0.001) were significantly associated with coexisting ADs. Regarding each concomitant AD, nail abnormalities were an associated factor for AITD (OR = 4.65, 95% CI = 1.96-7.24; P = 0.01), whereas coexisting atopic diseases were demonstrated as a predictor of vitiligo (OR = 2.48, 95% CI = 1.43-4.58; P = 0.02). Female sex (OR = 1.61, 95% CI = 1.18-4.27; P = 0.04) and family history of AD (OR = 1.85, 95% CI = 1.26-4.19; P = 0.03) were predictors of SLE.

CONCLUSION

This study suggests that female AA patients with nail abnormalities and atopic diseases have increased rates of AD comorbidities. A thorough review of systems for associated factors can help physicians screen for concomitant ADs.

Alopecia Areata: An Autoimmune Disease of Multiple Players

Alopecia areata (AA) is an autoimmune disease of the hair follicles. It is characterized by a well-defined non-scarring alopecic patch or patches that may extend to the entire scalp or lead to total body hair loss. Due to its unpredictable clinical course, AA causes substantial psychological harm. Despite the high prevalence of this disease and extensive research, its exact pathomechanism is unclear, and current treatments have a high relapse rate that has deemed AA incurable. Over the past few decades, researchers have investigated multiple potential factors that may help alleviate its pathogenesis and provide effective treatment. Given its complex immunopathogenesis, AA is considered an autoimmune disease with multiple factors. This review gathers current evidence that emphasizes molecular mechanisms, possible causative etiologies, and targeted immunotherapies for AA. Understanding its underlying mechanisms may shed light on new strategies to effectively manage AA in the future.

An Approach to Patients with Alopecia

Alopecia is a dermatologic condition in which sudden or gradual loss of hair occurs on 1 or more areas of the body, most commonly the scalp. Hair loss can be acute or chronic in nature as a result of underlying inflammation, autoimmune processes, stressors, chemotherapy, or hairstyling practices. Alopecia can have substantial psychological consequences, having a negative impact on the quality of life in affected patients. The ability to both recognize and distinguish these condition holds great significance not only in providing adequate and timely treatment to improve outcomes but also meeting patient needs.

A Comprehensive Literature Review of JAK Inhibitors in Treatment of Alopecia Areata

Alopecia areata (AA) is a chronic, immune-mediated form of nonscarring alopecia that is multifactorial and results in localized patches. It is often described as a self-limiting condition that results in the spontaneous regrowth of hair in most cases. However, this regrowth may take several months or years to occur in some patients, leading to the development of psychoemotional trauma in those that are affected. Although several therapies for AA have been developed and tested, there is no specific treatment that has been approved, leading to the availability of many off-label conventional treatment options, with very limited responses. More recently, with the advancement of pre-clinical and genetic studies, a greater understanding of the pathomechanisms involved in the development of AA has been uncovered. This has resulted in the introduction of targeted therapies that use small molecules to block specific pathways involved in AA pathophysiology. As such, the use of janus kinase (JAK) inhibitors for treatment of AA has emerged. JAK inhibitors block the T-cell mediated inflammatory response thought to be the driving factor behind AA pathogenesis, by inhibiting the janus kinase (JAK) signal transducer and activator of transcription (STAT) signaling pathway, leading to a reversal of hair loss in AA patients. Thus, in an effort to demonstrate the efficacy of JAK inhibitors in the treatment of AA, several studies have been published within recent years. However, the question remains, “Are JAK inhibitors effective and safe in the management of Alopecia Areata?”. This review aims to provide a comprehensive report on the role, efficacy, and outcomes of using JAK inhibitors in the treatment of AA. To competently answer the research question highlighted, the most recent, quality articles published over a 10–15-year period were sourced using PubMed, NCBI, Research gate, Medline, Cochrane Central Register of Controlled Trials, EMBASE and Google scholar. The literature search was primarily focused on randomized controlled trials (RCTs); however, in the absence of such, only the most recently published case reports, case series, clinical trials and open-label studies published to date were included.

Scalp Biophysical Characteristics in Males with Androgenetic Alopecia: A Comparative Study with Healthy Controls

Background

Androgenetic alopecia (AGA) is the most common type of hair loss in men. Its prevalence increases with advancing age. Characteristics of hair loss in male AGA reveal the possibility of different biophysical and physiological profiles between androgen-sensitive (vertex) and androgen-insensitive (occipital) scalps. However, these variations have not been well investigated.

Objective

We aimed to evaluate and compare scalp biophysical and physiological characteristics in male AGA patients and healthy controls.

Methods

Scalp biophysiological profiles were evaluated by non-invasive measuring techniques, including skin surface lipids (SSL), transepidermal water loss (TEWL), and stratum corneum hydration (SCH) on both vertex and occipital areas. Values were compared between scalp areas and study groups. Participants with AGA were further categorized based on disease severity (Hamilton-Norwood classification) for subgroup analyses. Correlation coefficients were evaluated to determine the effects of AGA severity and age on each functional parameter.

Results

Participants were 31 AGA subjects and 31 healthy controls. The vertex scalp of AGA patients had significantly higher SSL (p = 0.03) and lower SCH (p = 0.02) compared to the occipital scalp. TEWL was not significantly different (p = 0.31). AGA group SSL showed a positive correlation with severity of hair loss (r = 0.61, p = 0.03). When compared to controls, the AGA group vertex scalp had significantly higher SSL (p = 0.03) and lower TEWL (p < 0.001). The occipital area showed no statistically significant differences.

Conclusion

Male AGA presents with different biophysical and physiological characteristics in androgen-sensitive and androgen-insensitive areas, and with further differences from controls. These findings could direct further research and aid in the development of optimal hair and scalp treatments to improve scalp functional profiles in particular patients.

Application of Topical Immunotherapy in the Treatment of Alopecia Areata: A Review and Update

Treatment of extensive or recalcitrant alopecia areata (AA) is a major clinical challenge. Even after thorough investigation of several medications, its treatment outcomes have remained unsatisfactory. While there is no US Food and Drug Administration-approved medication for AA yet, topical immunotherapy has been a well-documented treatment option. Dinitrochlorobenzene, squaric acid dibutylester, and diphenylcyclopropenone are three substances that have demonstrated efficacy in the treatment of extensive or recalcitrant AA. Despite being commonly used, the mechanism underlying topical immunotherapy is not well-elucidated and a wide range of clinical efficacies have been reported in the literature. The aim of this review was to summarize and update the pharmacology, mechanism of action, therapeutic efficacy, and tolerability of topical immunotherapy in the treatment of AA.

Serum level of interleukin-15 in active alopecia areata patients and its relation to age, sex, and disease severity

Introduction

Autoimmune mechanisms with evident genetic background are the main components of alopecia areata (AA) pathogenesis. Interleukin 15 (IL-15) is considered as an important signalling cytokine. Its disordered expression has been linked to inflammatory autoimmune disorders.

Aim

The present study aimed to evaluate serum IL-15 in active AA patients and to assess its association with patients' sex, age, and disease severity.

Material and methods

IL-15 serum level was measured in 40 patients with active alopecia areata and 20 healthy controls using the ELISA technique. The severity of hair loss was assessed in accordance with the Severity of Alopecia Tool (SALT).

Results

A significantly higher serum level of IL-15 in AA patients than in controls was detected (p < 0.001). A significant positive correlation was detected between the SALT score and IL-15 serum level (r_s = 0.433, p = 0.005). No significant correlation between age of the patients and the serum level of IL-15 was observed (r_s = 0.224, p = 0.164). No significant difference in IL-15 serum level regarding patients' sex, history of disease recurrence, or family history of AA was noted.

Conclusions

The elevated serum level of IL-15 in active AA patients might reflect its role in disease pathogenesis as a key signalling cytokine. Its level is correlated with disease severity. However, IL-15 is not influenced by patients' gender or age.

The Use of Medicinal Plants for the Treatment of Alopecia in the Canon of Avicenna: An Evidence-Based Review

Although mostly seen in the scalp, alopecia can occur in any hair- bearing site of the body. In spite of various modern treatments, total cost, efficacy, safety and drug dependency have caused a global willing towards natural remedies. The aim of this chapter is to focus on medicinal plants mentioned in Canon of Avicenna, one of the most primary medicinal books, for the treatment of alopecia. Databases like PubMed, Scopus and Google Scholar were searched for plants mentioned in Canon for managing alopecia to find studies on their clinical efficacy or mechanisms, which may have attributed to the treatment of alopecia. 25 plants belonging to 16 families have been mentioned in Canon. Most of them have a history of use in ethno-medicine and some are used in hair growth products nowadays. Investigating literatures has shown that anti- inflammatory and immunomodulatory properties are the proposed mechanisms for the treatment of some types of alopecia. Islamic traditional medicine can give new insights for development of multiple natural treatment, which their use in human have been tested for thousands of years. By confirming their efficacy and safety, traditional herbal remedies are appropriate alternatives for chemicals mainly used for alopecia.

Synthesis and use of an amphiphilic dendrimer for siRNA delivery into primary immune cells

Using siRNAs to genetically manipulate immune cells is important to both basic immunological studies and therapeutic applications. However, siRNA delivery is challenging because primary immune cells are often sensitive to the delivery materials and generate immune responses. We have recently developed an amphiphilic dendrimer that is able to deliver siRNA to a variety of cells, including primary immune cells. We provide here a protocol for the synthesis of this dendrimer, as well as siRNA delivery to immune cells such as primary T and B cells, natural killer cells, macrophages, and primary microglia. The dendrimer synthesis entails straightforward click coupling followed by an amidation reaction, and the siRNA delivery protocol requires simple mixing of the siRNA and dendrimer in buffer, with subsequent application to the primary immune cells to achieve effective and functional siRNA delivery. This dendrimer-mediated siRNA delivery largely outperforms the standard electroporation technique, opening a new avenue for functional and therapeutic studies of the immune system. The whole protocol encompasses the dendrimer synthesis, which takes 10 days; the primary immune cell preparation, which takes 3-10 d, depending on the tissue source and cell type; the dendrimer-mediated siRNA delivery; and subsequent functional assays, which take an additional 3-6 d.

New and Emerging Therapies for Alopecia Areata

Alopecia areata (AA) is an autoimmune condition that affects up to 2% of the general population. Currently available treatment options for AA are of limited efficacy and can be associated with adverse effects. The advancement in understanding of the genetic and molecular mechanisms of AA has led to the development of novel treatment options, with the Janus kinase (JAK) inhibitor class of drugs at the forefront of ongoing clinical trials. Platelet-rich plasma, fecal transplants, and cytokine-targeted therapy with ustekinumab and dupilumab have also been shown to regrow hair in patients with AA in individual case reports or small studies. Several other novel therapies have preliminary data or are being tested in clinical trials.

Characterization and classification of different female hairline patterns in the Thai population

BACKGROUND

The hairline is an essential component of the human face. Disfigurement of the hairline may cause physical and psychological problems. Standard guidelines do not exist for female hairline designs, average values of infratemporal portion, hairline classifications, and preferences.

AIMS

We aimed to study hairline characteristics in Thai females and further compare the values with previous studies in different populations. Furthermore, we aimed to introduce a comprehensive hairline classification system that allowed an easy and detailed phenotypic characterization of female hairline.

PATIENTS/METHODS

Healthy Thai females aged over 18 years were included in the study. Collection of demographic data, infratemporal measurements, and standard photography was performed. All collected data were analyzed to determine the standard values of each hairline dimension for comparison to previous studies.

RESULTS

Two hundred and twenty-nine females, with a mean age of 32.4 ± 8.6 years, participated in this study. The mean mid-frontal line was 6.45 ± 0.89 cm, which was not correlated with age. Lateral mounds, widow's peaks, and cowlicks were observed in 42.35%, 24.45%, and 1.74% participants, respectively. Our study revealed five patterns of the frontal hairline and four patterns of the temporal hairline. The mid-frontal line in Asian females trended longer than that in Caucasians, without statistical significance.

CONCLUSIONS

Measurements of the infratemporal portions in Thai females revealed no change with age, and the mid-frontal line showed no statistically significant differences between Korean and Turkish participants. The hairline classification system introduced in our study was comprehensive and would be easily applicable in clinical practice. Female hairline dimensions and patterns reported in our study could provide reference values for hairline design in hairline restoration surgery as well as assist in accurate diagnosis of hair disorders.

Scoping Review on the Use of Drugs Targeting JAK/STAT Pathway in Atopic Dermatitis, Vitiligo, and Alopecia Areata

INTRODUCTION

The JAK/STAT signaling pathway is involved in the immune-mediated inflammatory skin diseases atopic dermatitis (AD), vitiligo, and alopecia areata (AA), and represents a potential target when developing treatments. So far, no drugs targeting this pathway have been approved for the treatment of dermatological diseases. We reviewed the use of drugs blocking the JAK/STAT pathway in the aforementioned diseases.

METHODS

An a priori protocol was published. We used Joanna Briggs Institute Reviewer's Manual methodology to conduct the review and PRISMA Extension for Scoping Review (PRISMA-ScR) to report results. MEDLINE, EMBASE, CINAHL, Scopus, and Web of Science databases were searched in a three-step approach on April 2019 by two researchers.

RESULTS

Ninety-six mainly multicenter observational studies were included (66, 10, and 20 studies on AA, vitiligo, and AD, respectively). Tofacitinib and ruxolitinib were mainly used for the three diseases, and also upadacitinib, abrocitinib, baricitinib, cerdulatinib, delgocitinib, gusacitinib for AD, and baricitinib, PF-06700841, and PF-06651600 for AA. All patients with AD improved, whereas patients with vitiligo and patients with AA showed varied responses, including unresponsive cases. The safety profiles were similar for all drugs and diseases, mainly comprising mild or no adverse events.

CONCLUSIONS

Evidence on the efficacy and safety of drugs targeting the JAK/STAT pathway for the treatment of patients with AD, vitiligo, or AA is increasing but is still of low quality.

Minoxidil and its use in hair disorders: a review

Minoxidil was first introduced as an antihypertensive medication and the discovery of its common adverse event, hypertrichosis, led to the development of a topical formulation for promoting hair growth. To date, topical minoxidil is the mainstay treatment for androgenetic alopecia and is used as an off-label treatment for other hair loss conditions. Despite its widespread application, the exact mechanism of action of minoxidil is still not fully understood. In this article, we aim to review and update current information on the pharmacology, mechanism of action, clinical efficacy, and adverse events of topical minoxidil.

Alopecia areata: A multifactorial autoimmune condition

Alopecia areata is an autoimmune disease that results in non-scarring hair loss, and it is clinically characterised by small patches of baldness on the scalp and/or around the body. It can later progress to total loss of scalp hair (Alopecia totalis) and/or total loss of all body hair (Alopecia universalis). The rapid rate of hair loss and disfiguration caused by the condition causes anxiety on patients and increases the risks of developing psychological and psychiatric complications. Hair loss in alopecia areata is caused by lymphocytic infiltrations around the hair follicles and IFN-γ. IgG antibodies against the hair follicle cells are also found in alopecia areata sufferers. In addition, the disease coexists with other autoimmune disorders and can come secondary to infections or inflammation. However, despite the growing knowledge about alopecia areata, the aetiology and pathophysiology of disease are not well defined. In this review we discuss various genetic and environmental factors that cause autoimmunity and describe the immune mechanisms that lead to hair loss in alopecia areata patients.

Hair-Growth Potential of Ginseng and Its Major Metabolites: A Review on Its Molecular Mechanisms

The functional aspect of scalp hair is not only to protect from solar radiation and heat/cold exposure but also to contribute to one's appearance and personality. Progressive hair loss has a cosmetic and social impact. Hair undergoes three stages of hair cycle: the anagen, catagen, and telogen phases. Through cyclical loss and new-hair growth, the number of hairs remains relatively constant. A variety of factors, such as hormones, nutritional status, and exposure to radiations, environmental toxicants, and medications, may affect hair growth. Androgens are the most important of these factors that cause androgenic alopecia. Other forms of hair loss include immunogenic hair loss, that is, alopecia areata. Although a number of therapies, such as finasteride and minoxidil, are approved medications, and a few others (e.g., tofacitinib) are in progress, a wide variety of structurally diverse classes of phytochemicals, including those present in ginseng, have demonstrated hair growth-promoting effects in a large number of preclinical studies. The purpose of this review is to focus on the potential of ginseng and its metabolites on the prevention of hair loss and its underlying mechanisms.