[Small Molecule Therapy for Inflammatory Bowel Disease: JAK Inhibitors and S1PR Modulators].

Small molecules, including Janus kinase (JAK) inhibitors and sphingosine-1-phosphate receptor modulators (S1PRMs), are promising new treatments for inflammatory bowel disease (IBD). Small molecules exhibit more predictable pharmacokinetics than biologics, are less likely to induce immune responses, and can be administered orally. JAK inhibitors function by blocking the activity of JAK enzymes, which prevents the subsequent phosphorylation and activation of signal transducer and activator of transcription (STAT) proteins. Tofacitinib and filgotinib are approved for treating ulcerative colitis (UC), while upadacitinib is approved for UC and Crohn's disease. Nevertheless, JAK inhibitors can increase the risk of herpes zoster, cancer, major adverse cardiovascular events, and venous thromboembolism. S1PRMs bind to S1PRs, particularly S1PR1, on lymphocytes. This interaction inhibits lymphocytes from exiting the lymph nodes and migrating to the gut, thereby reducing inflammation and the immune response in the intestinal mucosa. Ozanimod and etrasimod are S1PRMs approved for the treatment of UC, but they can cause side effects such as bradycardia, conduction disorder, and macular edema. Overall, JAK inhibitors and S1PRMs offer significant benefits in managing IBD, although their potential side effects require careful monitoring.

A meta-analysis of therapeutic trials of topical ruxolitinib cream for the treatment of vitiligo: therapeutic efficacy, safety, and implications for therapeutic practice.

Vitiligo, an autoimmune condition characterized by depigmented skin patches due to the loss of functional melanocytes, has been linked to dysregulation in the JAK-STAT signaling pathway, particularly in IFN-g signaling. The use of JAK inhibitors, such as ruxolitinib cream, a JAK1 and JAK2 inhibitor, presents a promising approach for vitiligo treatment. This study aims to systematically assess the effectiveness and safety of ruxolitinib cream in patients with vitiligo. We conducted a systematic review and meta-analysis following PRISMA guidelines to evaluate the efficacy and safety of ruxolitinib cream for the treatment of vitiligo. A comprehensive search of PubMed, Google Scholar, and Cochrane Library databases for randomized controlled trials (RCTs). Data selection, screening, extraction, and risk of bias assessment were meticulously performed. Statistical analysis was conducted using Review Manager Software, version 5.4, with significant heterogeneity addressed through appropriate methods. Our meta-analysis included 3 studies with 830 vitiligo patients. Significant improvements were observed in F-VASI, T-VASI, F-BSA, and T-BSA scores, with greater efficacy at 24 weeks compared to 12 weeks [MD -24.17, 95% CI (-31.78 to -16.56), P < 0.00001], [MD -14.12, 95% CI (-20.54 to -7.70); P < 0.0000], [MD -16.25, 95% CI (-22.20 to -10.31), P < 0.00001], [MD -9.19, 95% CI (-13.47 to -4.92); P < 0.00001]. Ruxolitinib showed increased risk ratios for F-VASI75, F-VASI90, and F-VASI50, indicating better outcomes with longer treatment durations [MD 2.9, 95% CI 1.88-4.49; P < 0.00001], [MD 4.66, 95% CI 2.09-10.39; P = 0.0002], [MD 2.53, 95% CI 1.84-3.46; P < 0.00001]. No significant differences were found in mild and moderate adverse events, while severe cases favored ruxolitinib. Placebo had a significant advantage in any adverse events, with no significant difference in drug-related adverse events. Serious adverse events did not significantly differ between groups. The findings strongly support the efficacy of ruxolitinib therapy in improving various parameters over time for treating vitiligo. However, thorough consideration of its safety profile, particularly concerning adverse events and potential side effects, is warranted. Further studies with larger sample sizes are needed to confirm these conclusions.

JAK Inhibitors in Cytokine Storm Syndromes.

Cytokine storm syndromes (CSSs) comprise a group of severe and often fatal hyperinflammatory conditions driven by the overproduction of pro-inflammatory cytokines by activated cells of the immune system. Many of the CSS-associated cytokines mediate their downstream effects by signaling through the Janus kinases (JAKs) and signal transducers and activators of transcription (STATs). In addition, several of these cytokines are produced downstream of JAK/STAT pathway activation. Therefore, targeting JAK/STAT signaling using small molecule JAK inhibitors has become an increasingly appealing therapeutic option to dampen hyperinflammation in patients with CSSs. Application of JAK inhibitors in preclinical CSS models has shown improvements in multiple sequelae of hyperinflammation, and there is growing clinical evidence supporting the efficacy of JAK inhibition in patients with these conditions. Although generally well tolerated, JAK inhibitor use is not without potential for toxicity, especially in settings like CSSs where end-organ dysfunction is common. More prospective clinical trials incorporating JAK inhibitors, alone or in combination with other immunomodulatory therapies, are necessary to determine the optimal dosing, schedule, efficacy, and tolerability of these agents for patients experiencing CSSs.

[Severe atopic dermatitis in childhood in the era of personalized medicine]. / Dermatitis atópica severa en la infancia en la era de la medicina personalizada.

Atopic dermatitis (AD) is a chronic, non-infectious inflammatory dermatosis, with increasing prevalence in recent decades. Due to its chronic and recurrent nature, it diminishes the quality of life of patients and their families. In recent years, advances in the understanding of AD's pathophysiology have driven the development of targeted therapies such as monoclonal antibodies (mAbs) and Janus kinase inhibitors (JAKis) which modulate the immune system through specific signaling pathways, providing effective alternatives to traditional systemic immunosuppressive agents. Four targeted therapies have been approved in the USA for the treatment of severe/refractory cases: dupilumab, tralokinumab, abrocitinib, and upadacitinib. This manuscript aims to present an update on the pathophysiology of AD, describe the new treatments available, and provide an analysis of the initial results of the use of these treatments in the pediatric population. We concluded that the high cost of these treatments often limits their prescription to situations where cases of atopic dermatitis are resistant to other conventional therapeutic options or when the disease reaches a severe degree. This underscores the importance of careful and accurate decision-making in the medical management of AD to ensure the efficient use of these therapeutic resources.

Anti-IL23/12 agents and JAK inhibitors for inflammatory bowel disease.

IBD (inflammatory bowel disease) is a chronic inflammatory disease of the gastrointestinal tract with increasing incidence worldwide. Multiple factors, such as genetic background, environmental and luminal factors, and mucosal immune dysregulation, have been implicated in the cause of IBD, although the cause of the disease remains unknown. IL-12 and IL-23 and their downstream signaling pathways participate in the pathogenesis of inflammatory bowel disease. Early and aggressive treatment with biologic therapies or novel small molecules is needed to decrease complications and the need for hospitalization and surgery. The landscape of inflammatory bowel disease (IBD) treatment has tremendously improved with the development of biologics and small molecule drugs. Several novel biologics and small molecule drugs targeting IL-12 and IL-23 and their downstream targets have shown positive efficacy and safety data in clinical trials, and several drugs have been approved for the treatment of IBD. In the future, numerous potential emerging therapeutic options for IBD treatment are believed to come to the fore, achieving disease cure.

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.

Peri-Arthroscopic Management of Immunosuppressive Medications in Patients with Rheumatic Disease A Survey of Practice Trends Among Rheumatologists and Sports Medicine Orthopedic Surgeons.

PURPOSE: Rheumatologists and orthopedic surgeons frequently collaborate on difficult decisions regarding perioperative management of immunosuppression in rheumatic disease patients, balancing risk of postoperative infection with risk of disease flares. Current evidence-based guidelines pertain specifically to arthroplasty, thus we sought to understand the trends and common practices regarding peri-arthroscopic use of immunosuppression. METHODS: Rheumatologists and sports medicine surgeons, from a variety of New York hospitals and serving a broad range of demographics, were surveyed on immunosuppressive medication management in rheumatic disease patients undergoing arthroscopic surgeries. Physicians' preferences were elicited regarding the use of common anti-rheumatic medications with the lower risk meniscectomies and the higher risk anterior cruciate ligament (ACL) reconstructions and allografts. Physicians were asked specifically about peri-arthroscopic use of conventional synthetic diseasemodifying antirheumatic drugs (csDMARDs), biologics, and Janus kinase (JAK) inhibitors. RESULTS: During the survey period, 25 rheumatologists and 19 sports medicine fellowship-trained orthopedic surgeons completed the questionnaire. For lower-risk arthroscopies, rheumatologists favored continuing various csDMARDs (72% to 100%), biologics (50% to 64%) and JAK inhibitors (57%), while a majority of surgeons concurred for all three drug classes (csDMARDs 63%; biologics 53%; and JAK inhibitors 58%). For higher-risk arthroscopies, most rheumatologists preferred that patients continue csDMARDs (63% to 100%) but fewer supported the use of biologics (28% to 39%) or JAK inhibitors (22%). Surgeons were more hesitant to endorse any class of immunosuppressive antirheumatic medications (22% to 27%) around these higher risk surgeries. The rheumatologists were most concerned about surgeries taking place too soon after the last dose of rituximab, recommending these higher risk surgeries not take place for 7.7 ± 8.8 weeks following the last infusion. CONCLUSION: For lower-risk arthroscopies, most rheumatologists but only about half of orthopedic surgeons preferred patients continuing csDMARDs. Approximately half of both groups preferred patients hold biologics and JAK inhibitors. In more involved arthroscopies, most rheumatologists but few orthopedists supported the continued use of csDMARDs, and the consensus was to hold all other immunosuppression when possible. While the duration medications were held perioperatively were somewhat reflective of the current guidelines for arthroplasty, there is a need for evidencebased guidelines specifically regarding peri-arthroscopy immunosuppression in rheumatic disease patients.

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.

Oral Janus Kinase Inhibitors in Pediatric Atopic Dermatitis.

PURPOSE OF REVIEW: To analyze the efficacy and safety of Janus kinase inhibitors (JAKi) in the treatment of pediatric AD. RECENT FINDINGS: Adolescents with moderate and severe atopic dermatitis (AD) need systemic therapies, as stated several recent practice guidelines. (JAKi) have shown their efficacy in the treatment of adult AD, however, there is a lack of information concerning efficacy and safety of their use in pediatric AD. We found that the JAKi's abrocitinib (ABRO), baricitinib (BARI), and upadacitinib (UPA), are all an effective treatment option with a very fast onset of action for adolescents with moderate-to-severe AD. BARI was not effective in children between 2 and 10 years with moderate-to-severe AD. Fortunately, major safety issues with JAKi in adolescents with AD have not been documented in the trials, so far, contrasting with the reports in adults with AD, where these events have very rarely occurred. There are some reports of herpes zoster (HZ) infection in adolescents on JAKi, but it is not a major safety concern. Acne is a relatively common AE with UPA in adolescents; however, it is responsive to standard treatment. This review will help the clinician to choose among the JAKi according to the needs and clinical features of patients with moderate and severe AD. In the following years, with the advent of new biologicals and JAKi, these therapies will fall into place in each phase of the evolution of patients with AD.

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.

The JAK1/JAK2 inhibitor ruxolitinib inhibits mediator release from human basophils and mast cells.

Introduction: The Janus kinase (JAK) family includes four cytoplasmic tyrosine kinases (JAK1, JAK2, JAK3, and TYK2) constitutively bound to several cytokine receptors. JAKs phosphorylate downstream signal transducers and activators of transcription (STAT). JAK-STAT5 pathways play a critical role in basophil and mast cell activation. Previous studies have demonstrated that inhibitors of JAK-STAT pathway blocked the activation of mast cells and basophils. Methods: In this study, we investigated the in vitro effects of ruxolitinib, a JAK1/2 inhibitor, on IgE- and IL-3-mediated release of mediators from human basophils, as well as substance P-induced mediator release from skin mast cells (HSMCs). Results: Ruxolitinib concentration-dependently inhibited IgE-mediated release of preformed (histamine) and de novo synthesized mediators (leukotriene C4) from human basophils. Ruxolitinib also inhibited anti-IgE- and IL-3-mediated cytokine (IL-4 and IL-13) release from basophils, as well as the secretion of preformed mediators (histamine, tryptase, and chymase) from substance P-activated HSMCs. Discussion: These results indicate that ruxolitinib, inhibiting the release of several mediators from human basophils and mast cells, is a potential candidate for the treatment of inflammatory disorders.

A case of refractory anti-MDA5-positive amyopathic dermatomyositis successfully treated with upadacitinib.

Purpose: Amyopathic dermatomyositis (ADM) is a rare, idiopathic, connective tissue disease and melanoma differentiation-associated protein 5 (MDA5) antibody-positive ADM is more treatment-resistant, especially in patients with interstitial lung disease (ILD). The purpose of this article is to report a case of anti-MDA5-positive ADM successfully treated with JAK inhibitor Upadacitinib.Materials and methods: A 35-year-old Chinese woman presented with recurrent itchy erythema on her face and scalp for 4 years. Upon examination, there were heliotrope erythema and eyelid edema, reddish rash on neck and scalp. Biopsy of the lesions was consistent with DM and a line blot assay confirmed the presence of anti-MDA5 antibodies. This patient was treated with oral Upadacitinib at a dosage of 30 mg daily.Results: After 6 weeks of treatment, she achieved complete clinical remission with no reported side effects or instances of relapse. The antibody titer of anti-MDA5 was also decreased.Conclusions: Upadacitinib may be a potential drug candidate in patients with treatment-resistant ADM, especially in cases with refractory cutaneous conditions.

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.

Response to biological drugs and JAK inhibitors following cyclosporine in patients with atopic dermatitis.

The therapeutic arsenal for atopic dermatitis (AD) has increased in recent years. The use of biologics or Janus kinase inhibitors (JAKi) is advocated following failure or contraindication to cyclosporine (CSA), however, it is not known whether treatment with CSA can impact the response to biologics or JAKi. The aim of this study was to evaluate the effect of previous treatment with CSA on response to biologics or JAKi in patients with AD. This was a retrospective observational study including patients with AD treated for 16 weeks with a biologic or JAKi, who had previously received cyclosporine for at least four weeks. Thirty patients with AD, with a mean age of 25.07±9.91 years, of whom 18 (60%) were women, were included. The mean duration of CSA treatment was 43.39±31.32 weeks. After 16 weeks of biologic or JAKi treatment, 17 (56.7%) patients achieved EASI75. These patients had a higher cumulative dose of CSA (3,6815 vs.76,993.33 mg; p=0.022) and a longer treatment duration (24.5 vs.57.4 weeks; p=0.003). Additionally, a negative correlation was observed between cumulative dose of CSA and EASI or SCORAD at 16 weeks. Previous cumulative dose and longer duration of CSA treatment does not appear to have a negative impact on response to biologics and JAKi in patients with AD.

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.

A Case of Scrofuloderma in a Patient on JAK Inhibitor Treatment for Rheumatoid Arthritis.

A 78-year-old woman with rheumatoid arthritis, who was started on baricitinib five or six months earlier, was referred to our hospital due to a subcutaneous abscess in her right axilla. Contrast-enhanced chest, abdomen, and pelvis computed tomography showed subcutaneous abscesses in her right axilla and lymphadenopathy with calcification. Cultures from the subcutaneous abscess and skin biopsy specimens were positive for Mycobacterium tuberculosis. These findings led to the diagnosis of scrofuloderma associated with tuberculous lymphadenitis. She was started on an antitubercular regimen of isoniazid, rifampicin, pyrazinamide, and ethambutol as the initial phase treatment (first 2 months), followed by isoniazid and rifampicin for 4 months (total 6 months). After 6 months of antitubercular treatment, the abscesses and lymphadenitis disappeared. Although cases of tuberculosis during JAK inhibitor treatment are rare, they are serious adverse events that require caution.

Janus kinase inhibitor tofacitinib successfully treated palmoplantar pustulosis after switching from secukinumab: A case report and review of the literature.

Palmoplantar pustulosis (PPP) is a chronic inflammatory recurrent disease characterized by sterile pustules involving palms and/or feet. Presently, there are no standard recommended treatment regimens. Tofacitinib is an oral Janus kinase (JAK) inhibitor, mainly acts on JAK 1 and 3 and has been approved for the treatment of rheumatoid arthritis in adults. Herein, we present a case of a patient with PPP who did not respond to IL-17A inhibitor secukinumab but was successfully treated by the JAK inhibitor tofacitinib.