Navigating therapeutic challenges in VEXAS syndrome: exploring IL-6 and JAK inhibitors at the forefront.

VEXAS syndrome, an uncommon yet severe autoimmune disorder stemming from a mutation in the UBA1 gene, is the focus of this paper. The overview encompasses its discovery, epidemiological traits, genetic underpinnings, and clinical presentations. Delving into whether distinct genotypes yield varied clinical phenotypes in VEXAS patients, and the consequent adjustment of treatment strategies based on genotypic and clinical profiles necessitates thorough exploration within the clinical realm. Additionally, the current therapeutic landscape and future outlook are examined, with particular attention to the potential therapeutic roles of IL-6 inhibitors and JAK inhibitors, alongside an elucidation of prevailing limitations and avenues for further research. This study contributes essential theoretical groundwork and clinical insights for both diagnosing and managing VEXAS syndrome.

Analysis of patient experiences regarding JAK inhibitors for atopic dermatitis, psoriasis, alopecia areata, and vitiligo.

The use of medications which target the JAK-STAT signaling pathway, also known as janus kinase (JAK) inhibitors, has rapidly increased in recent years. Patient perceptions, opinions, and concerns regarding the use of JAK inhibitors are largely uninvestigated. Our objective is to better understand patient concerns, reported side effects, and sentiments regarding the use of JAK inhibitors for dermatologic disease. The authors performed a cross-sectional analysis of the most frequented subreddits for dermatologic disease in which JAK inhibitors have obtained FDA approval (r/atopic dermatitis, r/psoriasis, r/alopecia areata, r/vitiligo, and r/eczeJAKS). The sentiment, central theme, and engagement level of each post was evaluated using previously utilized methods. Nine hundred twenty-three posts were analyzed, with the majority focusing on efficacy (433, 47%) and medication-related side effects (150, 16%). Other themes of interest to patients were Payment/Insurance (84, 9%), Study Results/News (69, 7%), Administration/Dosage (33, 4%), and Medication Interactions (31, 3%). The most frequently reported side effects were acne/folliculitis (24, 22%), nausea/gastrointestinal disturbance (11,10%), and fatigue/muscle aches (10, 9%). At the same time, the medication interactions garnering the most concern were sunscreens/facial moisturizers (5, 16%), topical calcineurin inhibitors (4, 13%), and Marijuana/THC (3, 9.%). This analysis highlights that patients are most concerned about the efficacy and side effects of JAK inhibitors in addition to issues regarding access to JAK inhibitors. Providers can use the insights gained from this study to address hesitancy better and guide comprehensive, patient-centered discussions with patients regarding JAK inhibitor use.

JAK inhibitors to treat STAT3 gain-of-function: a single-center report and literature review.

Objective: The signal transducer and activator of transcription 3 (STAT3) gain-of-function (GOF) syndrome (STAT3-GOF) is an inborn error of immunity (IEI) characterized by diverse manifestations of immune dysregulation that necessitate systemic immunomodulatory treatment. The blockade of the interleukin-6 receptor and/or the inhibition of the Janus kinases has been commonly employed to treat diverse STAT3-GOF-associated manifestations. However, evidence on long-term treatment outcome, especially in the case of adult patients, is scarce. Methods: Clinical data, including laboratory findings and medical imaging, were collected from all seven patients, diagnosed with STAT3-GOF, who have been treated at the Hannover University School, focusing on those who received a Janus kinase (JAK) inhibitor (JAKi). Previously published cases of STAT3-GOF patients who received a JAKi were evaluated, focusing on reported treatment efficacy with respect to diverse STAT3-GOF-associated manifestations of immune dysregulation and safety. Results: Five out of seven patients diagnosed with STAT3-GOF were treated with a JAKi, each for a different indication. Including these patients, outcomes of JAKi treatment have been reported for a total of 41 patients. Treatment with a JAKi led to improvement of diverse autoimmune, inflammatory, or lymphoproliferative manifestations of STAT3-GOF and a therapeutic benefit could be documented for all except two patients. Considering all reported manifestations of immune dysregulation in each patient, complete remission was achieved in 10/41 (24.4%) treated patients. Conclusions: JAKi treatment improved diverse manifestations of immune dysregulation in the majority of STAT3-GOF patients, representing a promising therapeutic approach. Long-term follow-up data are needed to evaluate possible risks of prolonged treatment with a JAKi.

JAK inhibitor selectivity: new opportunities, better drugs?

Cytokines function as communication tools of the immune system, serving critical functions in many biological responses and shaping the immune response. When cytokine production or their biological activity goes awry, the homeostatic balance of the immune response is altered, leading to the development of several pathologies such as autoimmune and inflammatory disorders. Cytokines bind to specific receptors on cells, triggering the activation of intracellular enzymes known as Janus kinases (JAKs). The JAK family comprises four members, JAK1, JAK2, JAK3 and tyrosine kinase 2, which are critical for intracellular cytokine signalling. Since the mid-2010s multiple JAK inhibitors have been approved for inflammatory and haematological indications. Currently, approved JAK inhibitors have demonstrated clinical efficacy; however, improved selectivity for specific JAKs is likely to enhance safety profiles, and different strategies have been used to accomplish enhanced JAK selectivity. In this update, we discuss the background of JAK inhibitors, current approved indications and adverse effects, along with new developments in this field. We address the issue of JAK selectivity and its relevance in terms of efficacy, and describe new modalities of JAK targeting, as well as new aspects of JAK inhibitor action.

Janus kinase inhibitors versus tumor necrosis factor inhibitors in rheumatoid arthritis: meta-analytical comparison of efficacy and safety.

BACKGROUND: Rheumatoid arthritis (RA) is a chronic systemic autoimmune disorder characterized by persistent inflammation leading to progressively worse disability. Janus kinase (JAK) inhibitors and tumor necrosis factor (TNF) inhibitors are pivotal in RA treatment, yet their comparative efficacy remains underexplored. AIM: This study aimed to compare the efficacy and safety of JAK inhibitors and TNF inhibitors in treating RA using data from randomized controlled trials (RCTs). METHODS: A meta-analysis and outcomes analysis were based on results of the Health Assessment Questionnaire Disability Index (HAQ-DI), Clinical Disease Activity Index (CDAI), Visual Analogue Scale (VAS), and Patient Global Assessment Scale (PtGA) and other indices as incidences of venous thromboembolism (VTE) and malignancy. RESULTS: The JAK inhibitors caused a statistically significant improvement in the HAQ-DI score [MD = 0.08, 95% CI (0.03, 0.12), p = 0.0008] compared with the TNF inhibitors. However, no significant difference was observed between the two drug classes in the CDAI score [MD = - 2.03, 95% CI (- 9.27, 5.22), p = 0.58]. JAK inhibitors were associated with an increase in the VAS score [MD = 3.62, 95% CI (0.86, 6.38), p = 0.01], but there was no significant difference in the PtGA score [MD = 1.91, 95% CI (- 3.25, 7.08), p = 0.47]. CONCLUSION: JAK inhibitors demonstrated superior efficacy in improving the functional status and reducing the disease activity in RA patients compared with TNF inhibitors. Both drug classes exhibited comparable safety profiles for VTE and malignancies, though JAK inhibitors had a higher risk for thromboembolism.

Humans are unreliable models of mouse disease.

In defying conventional views that dismissed itch as trivial, I persisted in studying basophils and ILC2s in human skin and atopic dermatitis. My research on JAK inhibitors for itch ultimately led to FDA-approved drugs. This is my story of disregarding categories and definitions-a story about an unconventional path in science that emphasizes innovation over conformity.

[JAK inhibitors for myelofibrosis: ruxolitinib and momelotinib].

Myelofibrosis should be diagnosed according to the WHO classification (2022, 5th Ed.) and International Consensus Conference 2022 criteria. Testing for driver mutations in the three genes JAK2, CALR, and MPL is recommended to ensure a definitive diagnosis. Ruxolitinib is the only JAK inhibitor currently approved in Japan, but momelotinib is under regulatory review. The MOMENTUM study showed similar spleen volume reduction at 24 weeks and MFSAF-TSS reduction as the COMFORT study of ruxolitinib. Momelotinib acts on ACVR1 and, therefore, improves anemia through suppression of hepcidin. Anemia and/or transfusion dependency are known to be associated with overall survival duration. Consequently, supportive care measures such as ESA and danazol in lieu of transfusion should be considered in addition to JAK inhibitor selection. Mean survival after discontinuation of JAK inhibitors is 11 to 14 months. Pacritinib (not approved in Japan) is suitable for MF patients with thrombocytopenia. JAK inhibitor selection and supportive care by ESA or danazol in lieu of transfusion should be considered. Many classes of drugs other than JAK inhibitors for myelofibrosis are under investigation.

Janus kinase inhibitors and adverse events of acne in dermatologic indications: a systematic review and network meta-analysis.

Background: The occurrence of acne in patients treated with Janus kinase (JAK) inhibitors for skin diseases is a potential issue, which may reduce treatment adherence.Purpose: To systematically analyzes randomized clinical trials (RCTs) of JAK inhibitors in dermatological indications for the risk of acne as an adverse event.Methods: A meta-analysis of odds ratios (ORs) for acne incidence was conducted. Data were quantitatively synthesized using random-effects meta-analysis. Surface under the cumulative ranking curve (SUCRA) values representing the relative ranking probabilities of treatments were obtained. Analyses were performed using R statistical software version 4.4.0.Results: A total of 11,396 patients were included from 24 studies. The incidence of acne for JAK inhibitors was ranked according to the SUCRA as follows: JAK1 inhibitors > TYK2 inhibitors > combined JAK1 and JAK2 inhibitors > combined JAK1 and TYK2 inhibitors > JAK3 + TEC inhibitors > pan-JAK inhibitors. ORs were higher for longer durations of drug use and larger dosages. Subgroup analyses by disease indication revealed increased ORs for psoriasis (5.52 [95% CI, 1.39-21.88]), vitiligo (4.15 [95% CI, 1.27-13.58]), alopecia areata (3.86 [95% CI, 1.58-9.42]), and atopic dermatitis (2.82 [95% CI, 1.75-4.54]). The use of JAK inhibitors in patients with systemic lupus erythematosus (SLE) may not significantly increase the incidence of acne.Conclusions: There are higher rates of acne following treatment with JAK inhibitors for dermatologic indications, particularly with longer durations and larger dosages. Pan-JAK inhibitors exhibit the lowest incidence of acne.

Use of Janus kinase inhibitors before and after European Medicines Agency safety recommendations: a retrospective study.

Background: Safety recommendations for Janus kinase inhibitors (JAKi) issued by the European Medical Agency (EMA) in 2023 could potentially influence treatment patterns for rheumatoid arthritis (RA) drugs, but little is known about the impact of these recommendations in routine clinical care. Methods: We retrospectively analyzed the German RHADAR rheumatology database for adult patients with RA and documentation of a new therapy with a JAKi, tumor necrosis factor inhibitor (TNFi), or interleukin-6 receptor inhibitor (IL-6Ri). Data were grouped into half-yearly intervals from quarter (Q)2/2020 to Q3/2023. The period from Q4/2022 to Q1/2023 immediately followed the initial EMA endorsement of Pharmacovigilance Risk Assessment Committee (PRAC) recommendations and Q2/2023-Q3/2023 immediately followed the direct healthcare provider communication (DHPC) containing the new safety JAKi recommendations. Results: Between April 1, 2020 and September 23, 2023, 3008 newly initiated therapies for TNFi (1499 [49.8%]), JAKi (1126 [37.4%]), and IL-6Ri (383 [12.7%]) were documented by the treating physicians. JAKi were increasingly used in the first two half-year periods (from 29.7% of these therapies in Q2/2020-Q3/2020 to 46.7% in Q2/2021-Q3/2021; odds ratio [OR] 2.08; p<0.001). The proportion of initiated JAKi therapies decreased significantly after the PRAC recommendations (32.9%; OR vs peak 0.56; p=0.001) and the DHPC letter (26.1%; OR vs peak 0.40; p<0.001). JAKi were more likely to be used as >3rd-line therapy in later time periods. Conclusions: This exploratory study suggests that EMA safety recommendations for JAKi influenced treatment patterns of RA patients who received JAKi in Germany. Additional studies will be needed to confirm these findings.

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.

JAK inhibition in Down Syndrome Regression Disorder.

Down Syndrome Regression Disorder (DRSD) is an uncommon but devastating condition affecting primarily adolescents and young adults with Down syndrome (DS). Individuals with DS display a dysregulated immune system associated with hyperactive interferon signaling, which is associated with a high incidence of autoimmune conditions. While the cause of DSRD is unknown, increasing evidence indicates that it may have an immune basis, and some individuals with DSRD have responded to intravenous immunoglobulin therapy. This case series describes three individuals with probable DSRD who received the JAK inhibitor tofacitinib and saw improvement in DSRD symptoms across multiple domains of neurological function.

Momelotinib versus ruxolitinib in JAK inhibitor-naïve patients with myelofibrosis: an efficacy/safety analysis in the Japanese subgroup of the phase 3 randomized SIMPLIFY-1 trial.

Momelotinib, an oral Janus kinase (JAK) 1/2 and activin A receptor type 1 inhibitor, improved symptoms, splenomegaly, and anemia in patients with myelofibrosis (MF). This sub-analysis of SIMPLIFY-1 evaluated the efficacy and safety of momelotinib versus ruxolitinib in Japanese patients with JAK inhibitor (JAKi)-naïve MF. Patients were randomized 1:1 to receive momelotinib 200 mg once daily or ruxolitinib 20 mg twice daily (or modified based on label) for 24 weeks, after which patients could receive open-label momelotinib. The primary endpoint was splenic response rate (SRR; ≥ 35% reduction in spleen volume) at 24 weeks; main secondary endpoints were total symptom score (TSS) response (≥ 50% reduction) and transfusion independence (TI) rates. Fifteen Japanese patients (momelotinib, n = 6; ruxolitinib, n = 9) were enrolled; all completed treatment. At Week 24, SRR was 50.0% with momelotinib and 44.4% with ruxolitinib. TSS response rates were 33.3% and 0%, and TI rates were 83.3% and 44.4%. Any-grade treatment-related adverse event (TRAE) rates were 83.3% with momelotinib and 88.9% with ruxolitinib. Grade 3/4 TRAE rates were 0% and 55.6%, with specific events being anemia (55.6%) and vertigo (11.1%) with ruxolitinib. Momelotinib was well tolerated, improved spleen and symptom responses, and reduced transfusion requirements in Japanese patients with JAKi-naïve MF.

JAK inhibition with tofacitinib rapidly increases contractile force in human skeletal muscle.

Reduction in muscle contractile force associated with many clinical conditions incurs serious morbidity and increased mortality. Here, we report the first evidence that JAK inhibition impacts contractile force in normal human muscle. Muscle biopsies were taken from patients who were randomized to receive tofacitinib (n = 16) or placebo (n = 17) for 48 h. Single-fiber contractile force and molecular studies were carried out. The contractile force of individual diaphragm myofibers pooled from the tofacitinib group (n = 248 fibers) was significantly higher than those from the placebo group (n = 238 fibers), with a 15.7% greater mean maximum specific force (P = 0.0016). Tofacitinib treatment similarly increased fiber force in the serratus anterior muscle. The increased force was associated with reduced muscle protein oxidation and FoxO-ubiquitination-proteasome signaling, and increased levels of smooth muscle MYLK. Inhibition of MYLK attenuated the tofacitinib-dependent increase in fiber force. These data demonstrate that tofacitinib increases the contractile force of skeletal muscle and offers several underlying mechanisms. Inhibition of the JAK-STAT pathway is thus a potential new therapy for the muscle dysfunction that occurs in many clinical conditions.

Restoration of Skin Barrier Abnormalities with IL4/13 Inhibitors and Jak Inhibitors in Atopic Dermatitis: A Systematic Review.

Background and Objectives: Atopic dermatitis is a chronic inflammatory skin disorder with a significant burden on patients' quality of life. This systematic review aims to evaluate the restoration of skin barrier abnormalities with interleukin-4/interleukin-13 (IL-4/IL-13) inhibitors and Janus kinase (JAK) inhibitors in atopic dermatitis. Materials and Methods: A comprehensive review of the literature was conducted, focusing on studies that assess the use of IL-4/IL-13 inhibitors and JAK inhibitors for atopic dermatitis. We identified eligible studies by searching Medline via PubMed with a special focus on their effect on the restoration of the epidermal barrier. Included studies evaluated the transepidermal water loss (TEWL), the reduction in epidermal thickness (ET), the improvement in ceramide synthesis, and the increase in stratum corneum hydration (SCH) with IL-4/IL-13 inhibitors and JAK inhibitors. The quality of included studies was assessed using the ROBINS-I and the RoB 2.0 tool for assessing the risk of bias. Results: Ten of the included studies concern dupilumab, while two concern JAK inhibitors. Ten were observational studies and two were randomized controlled trials (RCTs). The total number of included participants was 378 concerning dupilumab and 38 concerning JAK inhibitors. Five studies did not include any comparison group, three included healthy volunteers, two were conducted versus placebo, and two compared dupilumab with other treatments. The follow-up period ranged between 29 days and 32 weeks. The results demonstrated a significant decrease in transepidermal water loss (TEWL) and an increase in SCH on eczematous lesions for patients with sustained response to dupilumab treatment and observed improvements in ET and filaggrin (FLG) staining, which further support the efficacy of JAK inhibitors in enhancing skin barrier function. Conclusions: This review underscores the efficacy of IL-4/IL-13 inhibitors in improving skin barrier function. However, the limited number of studies focusing on JAK inhibitors and the overall lack of RCTs highlight the need for further research to establish the definitive role of IL-4/IL-13 inhibitors and JAK inhibitors in the restoration of the skin barrier.

Safety and effectiveness of tofacitinib in Korean adult patients with ulcerative colitis: post-marketing surveillance study.

BACKGROUND: Tofacitinib is an oral Janus kinase inhibitor for the treatment of ulcerative colitis (UC). We aimed to identify the safety and effectiveness of tofacitinib in patients with UC in routine clinical settings in Korea. METHODS: This open-label, observational, prospective, post-marketing surveillance study was conducted at 22 hospitals in the Republic of Korea. Patients with moderate to severe active UC who received tofacitinib were included and followed up for up to 52 weeks. Tofacitinib was administered at a dosage of 10 mg twice daily for at least 8 weeks, followed by 5 or 10 mg twice daily at the investigator's discretion based on clinical evaluation according to the approved Korean label. Safety including adverse events (AEs) and effectiveness including clinical remission, clinical response, and endoscopic mucosal healing were evaluated. Safety analysis set was defined as all patients registered for this study who received at least one dose of tofacitinib according to the approved Korean label and followed up for safety data. Effectiveness analysis set included patients in the safety analysis set who were evaluated for overall effectiveness assessment and excluded patients who had received tofacitinib less than 8 weeks. RESULTS: A total of 110 patients were enrolled, of whom 106 patients were included in the safety population. The median duration of treatment was 370 days and the treatment duration ranged from 16 to 684 days for the safety population. AEs occurred in 42 patients (39.6%). Serious AEs (SAEs) occurred in 7 patients (6.6%) and of them, there were 2 cases of serious infections. These serious infections were reported as Adverse Event of Special Interest (AESI) in this study and no other AESI were reported. There were no cases of death during the study period. Clinical remission rates were 40.0%, 46.7%, 57.6%, and 55.1% at 8, 16, 24, and 52 weeks, and clinical response rates were 77.8%, 87.9%, 56.6%, and 81.4% at each visit, respectively. Endoscopic mucosal healing rates were 58.7% at 16 weeks and 46.2% at 52 weeks. CONCLUSION: Tofacitinib was effective in Korean patients with moderate to severe active UC and the safety findings were consistent with the known safety profile of tofacitinib. This study confirmed the safety and effectiveness of tofacitinib in Korean patients with moderate to severe active UC in routine clinical settings. TRIAL REGISTRATION: This study is registered in the ClinicalTrials.gov under the identifier NCT04071405, registered on 28 August 2019.

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

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