Baricitinib: therapeutic potential for moderate to severe atopic dermatitis

JAK Inhibitors in Rheumatoid Arthritis: Immunomodulatory Properties and Clinical Efficacy

Rheumatoid arthritis (RA) is a highly prevalent autoimmune disorder. The pathogenesis of the disease is complex and involves various cellular populations, including fibroblast-like synoviocytes, macrophages, and T cells, among others. Identification of signalling pathways and molecules that actively contribute to the development of the disease is crucial to understanding the mechanisms involved in the chronic inflammatory environment present in affected joints. Recent studies have demonstrated that the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway regulates the behaviour of immune cells and contributes to the progression of RA. Several JAK inhibitors, such as tofacitinib, baricitinib, upadacitinib, and filgocitinib, have been developed, and their efficacy and safety in patients with RA have been comprehensively investigated in a number of clinical trials. Consequently, JAK inhibitors have been approved and registered as a treatment for patients with RA. In this review, we discuss the involvement of JAK/STAT signalling in the pathogenesis of RA and summarise the potential beneficial effects of JAK inhibitors in cells implicated in the pathogenesis of the disease. Moreover, we present the most important phase 3 clinical trials that evaluated the use of these agents in patients.

Blocking the IL-4/IL-13 Axis versus the JAK/STAT Pathway in Atopic Dermatitis: How Can We Choose?

Atopic dermatitis (AD) is an immune-mediated skin disorder with a chronic-relapsing course and a multifactorial pathogenesis. In contrast to the traditional concept of AD as solely a type 2 immune-activated disease, new findings highlight the disease as highly heterogeneous, as it can be classified into variable phenotypes based on clinical/epidemiological or molecular parameters. For many years, the only therapeutic option for moderate-severe AD was traditional immunosuppressive drugs. Recently, the area of systemic therapy of AD has significantly flourished, and many new substances are now marketed, licensed, or in the last step of clinical development. Biological agents and small molecules have enriched the therapeutic armamentarium of moderate-to-severe AD, such as dupilumab, tralokinumab, lebrikizumab (monoclonal antibodies targeting the IL-4/13 pathway), abrocitinib, upadacitinib, and baricitinib (JAK inhibitors). Indeed, the AD treatment paradigm is now split into two main approaches: targeting the IL-4/13 axis or the JAK/STAT pathway. Both approaches are valid and have strong evidence of preclinical and clinical efficacy. Therefore, the choice between the two can often be difficult and represents a major challenge for dermatologists. Indeed, several important factors must be taken into account, such as the heterogeneity of AD and its classification in phenotypes, patients' comorbidities, age, and personal preferences. The aim of our review is to provide an overview of the clinical and molecular heterogeneities of AD and to explore the factors and parameters that, in clinical practice, may help inform clinical decision-making.

Therapeutic Potential of Targeting the JAK/STAT Pathway in Psoriasis: Focus on TYK2 Inhibition

Psoriasis is an inflammatory skin disease with a chronic relapsing course and an often-detrimental impact on patients' quality of life. Thanks to incredible advances in research over the past few decades, the therapeutic armamentarium of psoriasis is now reasonably broad and structured, with several therapeutic agents that have demonstrated successful long-term control of this condition. However, there are still unfulfilled gaps resulting from the inherent limitations of existing therapies, which have paved the way for the identification of new therapeutic strategies or the improvement of existing ones. A great deal of attention has recently been paid to the JAK/STAT pathway, playing a crucial role in chronic inflammatory skin diseases, including psoriasis. Indeed, in a disease with such a complex pathogenesis, the possibility to antagonize multiple molecular pathways via JAK/STAT inhibition offers an undeniable therapeutic advantage. However, data from clinical trials evaluating the use of oral JAK inhibitors in immune-mediated disorders, such as RA, have arisen safety concerns, suggesting a potentially increased risk of class-specific AEs such as infections, venous thromboembolism, and malignancies. New molecules are currently under investigation for the treatment of psoriasis, such as deucravacitinib, an oral selective inhibitor that binds to the regulatory domain of TYK2, brepocitinib (PF-06700841) and PF-06826647 that bind to the active site in the catalytic domain. Due to the selective TYK2 blockade allowing the inhibition of key cytokine-mediated signals, such as those induced by IL-12 and IL-23, anti-TYK2 agents appear to be very promising as the safety profile seems to be superior compared with pan-JAK inhibitors. The aim of our review is to thoroughly explore the rationale behind the usage of JAK inhibitors in PsO, their efficacy and safety profiles, with a special focus on oral TYK2 inhibitors, as well as to provide a forward-looking update on novel therapeutic strategies targeting the TYK2 pathway in psoriasis.

Janus kinase inhibitors in atopic dermatitis: an umbrella review of meta-analyses

Background

Clinicians and healthcare policymakers have been drenched with a deluge of overlapping meta-analyses (MAs), and the necessity for comprehensive and clearly defined evidence of Janus kinase inhibitors (JKIs) in atopic dermatitis (AD) is urgent.

Methods

Six databases were searched for MAs published until October 2023. Qualitative description of MAs was mainly used, and Investigator's Global Assessment response (IGA response), the 75% improvement in Eczema Area and Severity Index (the EASI75), peak pruritus Numerical rating score (PP-NRS), and adverse effects were cited to describe the efficacy and safety of JKIs. The methodological quality of the included MAs was assessed by A Measurement Tool to Assess Systematic Reviews II (AMSTAR II), and the quality of evidence was evaluated by the grading of recommendations, assessment, development, and evaluation (GRADE).

Results

Sixteen MAs were pooled in this review, of which five studies appraised JKIs, five appraised systemic JKIs, five papers assessed abrocitinib only, and one assessed baricitinib. Two studies were of "high" methodological quality and 14 MAs were of "moderate" quality. Eleven MAs integrated the results of JKIs and reported that JKIs provide faster onset of IGA response (RR=2.83, 95% CI [2.25, 3.56], high-quality evidence). Similarly, 10 MAs showed that JAK inhibitors were more effective in improving the EASI75 (RR=2.84, 95% CI [2.2, 3.67], high-quality evidence). Results from 12 MAs showed JKIs were active in reducing the PP-NRS (SMD=-0.49, 95% CI [-0.67, -0.32]). All MAs affirmed JKIs added no adverse effects leading to discontinuation and serious adverse events (P<0.05). However, 200mg of abrocitinib had a higher risk of acne (RR=4.34, 95% CI [1.61, 11.71), herpes zoster (RR=1.64, 95% CI [0.42, 6.39]), headache (RR=1.76, 95% CI [1.03, 3]), and nausea (RR=7.81, 95% CI [3.84, 15.87]). Upadacitinib was known to increase acne (RR=6.23, 95% CI [4.08, 9.49]), nasopharyngitis (RR=1.36, 95% CI [1.03, 1.8]) and blood creatine phosphokinase (blood CPK) (RR=2.41, 95% CI [1.47, 3.95]). Baricitinib at 2mg was associated with increased blood CPK (RR=2.25, 95% CI [1.1, 2.97]).

Conclusion

Compared to placebo or dupilumab, the administration of JKIs can ameliorate IGA response more effectively, improve the EASI75, and relieve pruritus without severe adverse effect, while accompanied by more acne, nasopharyngitis, headache, and digestive disturbances. The curative effect of 200 mg of abrocitinib is significant and more caution should be given in patients with gastrointestinal dysfunction, herpes zoster, and those who are acne-prone. Baricitinib and upadacitinib should be avoided in populations at high risk for cardiovascular events.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=369369, PROSPERO (CRD42022369369).

Immunoglobulin G4-related Dacryoadenitis Successfully Treated with Baricitinib

A 48-year-old woman visited our hospital because of bilateral lacrimal gland enlargement. Her serum immunoglobulin G4 (IgG4) level was high, and positron emission tomography-computed tomography showed significant positive findings in the bilateral lacrimal gland. A biopsy revealed a considerable increase in IgG4/CD138, leading to a diagnosis of IgG4-related dacryoadenitis. The disease did not respond to steroid therapy, so treatment was started with baricitinib because of exacerbation of the original atopic dermatitis and dacryoadenitis after the second dose of the coronavirus disease 2019 (COVID-19) vaccine. Baricitinib was effective for resolving both dermatitis and dacryoadenitis, and steroids were able to be discontinued. The IgG4 level also improved.

Comparing the psychometric properties of the EQ-5D-3L and EQ-5D-5L descriptive systems and utilities in atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is a common chronic inflammatory skin disorder affecting up to 10% of adults. The EQ-5D is the most commonly used generic preference-accompanied measure to generate quality-adjusted life years (QALYs) for economic evaluations.

OBJECTIVES

We aimed to compare psychometric properties of the three-level and five-level EQ-5D (EQ-5D-3L and EQ-5D-5L) in adult patients with AD.

METHODS

In a multicentre cross-sectional study, 218 AD patients with a broad range of severity completed the EQ-5D-3L, EQ-5D-5L, Dermatology Life Quality Index (DLQI) and Skindex-16. Disease severity outcomes included the Investigator Global Assessment, Eczema Area and Severity Index and the objective SCORing Atopic Dermatitis.

RESULTS

A good agreement was established between the two EQ-5D versions with an intraclass correlation coefficient of 0.815 (95% CI 0.758-0.859, p < 0.001). Overall, 33 different health state profiles occurred in the EQ-5D-3L and 84 in the EQ-5D-5L. Compared to the EQ-5D-3L, ceiling effect was reduced for the mobility, self-care, usual activities and pain/discomfort dimensions by 4.6-11.5%. EQ-5D-5L showed higher average relative informativity (Shannon's evenness index: 0.64 vs. 0.59). EQ-5D-5L demonstrated better convergent validity with EQ VAS, DLQI and Skindex-16. The two measures were similar in distinguishing between groups of patients based on disease severity and skin-specific quality of life with a moderate or large effect size (η2 = 0.083-0.489).

CONCLUSION

Both instruments exhibited good psychometric properties in AD; however, the EQ-5D-5L was superior in terms of ceiling effects, informativity and convergent validity. We recommend the use of the EQ-5D-5L to measure health outcomes in clinical settings and for QALY calculations in AD.

Pharmacodynamics of Janus kinase inhibitors for the treatment of atopic dermatitis

INTRODUCTION

Atopic dermatitis (AD) is the most common inflammatory skin disorder. Despite the high disease burden, the therapeutic options are limited and their efficacy in controlling AD might be partially satisfactory.

AREAS COVERED

Most of the key mediators in AD pathogenesis act through the JAK/STAT signaling pathway, which represents a valid therapeutic target. The first generation of JAK inhibitors, namely tofacitinib and ruxolitinib, inhibit multiple JAKs, whereas newer JAK inhibitors show more selective inhibitory effects for specific JAKs. The aim of this review was to discuss the role of the JAK/STAT pathway in AD and its inhibition, with a special focus on pharmacodynamic properties. We checked the English-language literature, published in the last 15 years using PubMed, Google Scholar, and Scopus.

EXPERT OPINION

JAK inhibitors have different selectivity for various JAK molecules, which influences their pharmacodynamics, efficacy and safety profile. Since many key cytokines in AD signal through JAK1, and as the selective JAK1 inhibition may be effective, avoiding the concomitant inhibition of JAK2- and JAK3-dependent pathways could be associated with additional safety issues. Therefore, selective JAK1 inhibitors may represent promising therapeutic agents for AD, as they might prevent off-target effects of JAK inhibitors, especially related to the hematologic profile.

General and Skin-Specific Health-Related Quality of Life in Patients With Atopic Dermatitis Before and During the COVID-19 Pandemic

BACKGROUND

Few studies have investigated health-related quality of life (HRQoL) in patients with atopic dermatitis (AD) during the COVID-19 pandemic.

OBJECTIVES

The objectives of this study were to compare HRQoL in adult AD patients before and during the pandemic and to assess measurement performance of 4 HRQoL measures.

METHODS

Between 2018 and 2021, a multicenter, cross-sectional survey was conducted, involving 218 adult AD patients. Health-related quality of life outcomes included the EQ-5D-5L, Skindex-16, Dermatology Life Quality Index (DLQI), and DLQI-Relevant (DLQI-R). Severity was measured using objective SCORing Atopic Dermatitis, Eczema Area and Severity Index, and Investigator Global Assessment.

RESULTS

The mean ± SD EQ-5D-5L utility, Skindex-16, DLQI, and DLQI-R scores were 0.82 ± 0.22, 56.84 ± 27.46, 13.44 ± 8.46, and 13.76 ± 8.60, respectively. The patients reported more problems during the pandemic (P < 0.05) regarding pain/discomfort (odds ratio [OR], 1.78), worrying (OR, 1.89), concerns about persistence/reoccurrence of disease (OR, 1.88), and social relationships (OR, 1.69). The HRQoL outcomes showed strong correlations with each other (range of rs, |0.69| to |0.99|). The Skindex-16, DLQI, and DLQI-R were able to discriminate between severity groups with large (η2 = 0.20-0.23), whereas the EQ-5D-5L with moderate effect sizes (η2 = 0.08-0.11).

CONCLUSIONS

Atopic dermatitis patients experienced significantly more problems in some areas of HRQoL during the pandemic. The EQ-5D-5L, Skindex-16, DLQI, and DLQI-R demonstrated good convergent and known-group validity and can be suitable instruments for HRQoL assessment in clinical and research settings.

Baricitinib: The First Jak Inhibitor Approved in Europe for the Treatment of Moderate to Severe Atopic Dermatitis in Adult Patients

Background: Atopic dermatitis (AD) is an inflammatory skin disease characterized by a wide phenotypic variety with a very complex pathophysiological mechanism that has led to the identification of new therapeutic targets, such as janus kinasis (JAK) inhibitors. Objectives: To evaluate the efficacy and safety of baricitinib, the first JAK 1 and 2 inhibitor approved in Europe for the treatment of adult patients with moderate-to-severe AD. Methods: The efficacy and safety data available from the Phase III studies belonging to the BREEZE AD program are presented. Results: Results from BREEZE-AD1, AD2, AD4, and AD7 showed the efficacy of Baricitib 4 mg, administered orally, once daily, as monotherapy or in combination with topical corticosteroid (TCS), with a significant proportion of patients achieving primary endpoints IGA 0-1 (16.4% vs. 4.8%; 13.8% vs. 4.5%; 21.7% vs. 9.7%; 30.6% vs. 14.7%) and EASI75 (24.8% vs. 8.8%; 21.1% vs. 6.1%; 31.5% vs. 17.2%; 47.7% vs. 22.9%) at week 16 (W16) compared to placebo, respectively. Baricitinib showed rapid improvement in symptoms, starting from week 1 of treatment at 4 mg dosage, with a good safety profile. Nasopharyngitis, upper respiratory tract infections (URIs), creatine phosphokinase (CPK) elevations, and headache were the most frequently reported adverse events. Conclusions: Following the efficacy and safety data on W 16 from the phase III BREEZE-AD studies, baricitinib has recently been approved in Europe for the treatment of moderate to severe AD in adult patients. Further data to evaluate long-term efficacy and safety in a real-life setting are needed.

Targeting IL-4 for the Treatment of Atopic Dermatitis

Atopic dermatitis (AD) is an immune-mediated inflammatory skin disease characterized by a predominant type 2 immune response. Type 2 immunity is driven by multiple cytokines, including interleukin (IL)‑4 and IL-13 that are considered central to AD pathogenesis and key therapeutic targets. The dual inhibition of these two cytokines or the selective inhibition of IL-13 proved elevated efficacy in treating AD, whereas the selective inhibition of IL-4 has been poorly investigated as IL-4 inhibiting agents did not show any advance in clinical development programs. This review describes the pathogenic role of IL-4 in AD and briefly resumes the main features of compounds selectively blocking IL-4.