Current evidence for janus kinase inhibitors in adult and juvenile dermatomyositis and key comparisons

INTRODUCTION

Adult dermatomyositis (DM) and juvenile dermatomyositis (JDM) are rare autoimmune diseases with characteristic skin rashes, weakness, and other systemic features. Upregulated interferon signaling has been consistently described in both adult and juvenile DM which makes janus kinase inhibitors (jakinibs) an attractive therapeutic agent that has a targeted mechanism of action.

AREAS COVERED

Herein is a review of the growing literature of jakinib use in adult and juvenile DM, including reports on specific disease features and safety of jakinibs in this population and a comparison between adult and juvenile DM. We performed a literature review using PubMed including all English-language publications before 1 February 2024 and abstracts from key recent rheumatology conferences.

EXPERT OPINION

Jakinibs are an exciting and promising treatment in both adult and juvenile DM. Current Phase 2 and 3 randomized placebo-controlled trials of jakinibs in both adult and JDM will provide significant insights into the efficacy of this class of medication as a potentially more mechanistically targeted treatment of both skin and muscle disease. In fact, these results will likely inform the treatment paradigm of dermatomyositis in that it may even be considered as first or second line. The next five years in the therapeutic landscape of both juvenile and adult DM is an exciting time for both patients and medical providers.

Treatment with Janus kinase inhibitors in juvenile dermatomyositis: A review of the literature

BACKGROUND/OBJECTIVES

Janus kinase (JAK) inhibitors have been increasingly used in the treatment of juvenile dermatomyositis (JDM). This review aims to comprehensively analyze previous studies concerning the utilization of JAK inhibitors in JDM patients.

METHODS

We conducted a thorough review of MEDLINE and Scopus databases, spanning from their inception to September 1st, 2023, to identify articles involving JDM patients treated with JAK inhibitors.

RESULTS

Our literature search yielded 26 articles that encompassed 195 patients with JDM who received JAK inhibitors. The median (min-max) age of the patients was 4.9 (1-17) years (F/M:1.2). The most frequently used JAK inhibitor was tofacitinib (57.4 %), and improvement was achieved in 89.7 % of patients treated with tofacitinib. The improvement rate for ruxolitinib, which was the second most frequently used JAK inhibitor (27.2 %), was 69.2 %. For baricitinib (15.4 %), the improvement rate was 92.7 %. The most prevalent indication for JAK inhibitor use was resistant/recurrent skin involvement (34.7 %) followed by resistant/recurrent muscle involvement (28.6 %). Adverse events were reported in 72.1 % of the patients; an increase in infections (especially upper respiratory tract infections) was the most common side effect.

CONCLUSION

Our findings suggest that JAK inhibitors may be a good therapeutic option, particularly in the management of refractory JDM cases with an acceptable safety profile. However, further controlled studies are essential to establish a higher level of evidence for the optimal use of JAK inhibitors in JDM treatment.

Updates on efficacy and safety janus kinase inhibitors in juvenile dermatomyositis

INTRODUCTION

Juvenile dermatomyositis (JDM) is a rare autoimmune disease most commonly with proximal weakness due to inflammation and characteristic skin rashes. Most patients have a chronic or polycyclic disease course on standard therapy so better treatments are needed. An interferon signature is well-established in key tissues of JDM. Janus kinase inhibitors (jakinibs), which can decrease IFN signaling, are therefore appealing as a targeted therapy.

AREAS COVERED

Herein is a review of the growing literature on JDM patients in jakinibs, including specifics of their jakinib exposure, summary of efficacy, disease features, and characteristics of patients treated, and safety parameters.

EXPERT OPINION

The vast majority of refractory JDM patients respond to jakinib therapy, though they have varied features, doses, and previous/concurrent medications, and data is largely retrospective. Jakinibs are an exciting and promising treatment in JDM. Evaluation with larger prospective controlled studies is needed to answer remaining questions about jakinibs in JDM regarding dosing, which JDM patients to treat with jakinibs, potential biomarkers to use, and how best to monitor safety risks in JDM.

Successful treatment with tofacitinib for anti-melanoma differentiation-associated gene 5 antibody-positive juvenile dermatomyositis: case reports and review of the literature

Although the clinical efficacy of tofacitinib has been reported in adult patients with anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive (Ab+) dermatomyositis, data on its use in refractory juvenile dermatomyositis (JDM) are scarce. We describe two female Japanese patients with anti-MDA5 Ab + JDM and rapidly progressive interstitial lung disease who achieved remission by adding tofacitinib to existing immunosuppressive drugs and present a literature review. While both patients received various immunosuppressive or anti-inflammatory treatments for induction therapy, remission could not be achieved. Subsequently, tofacitinib was administered to reduce the Krebs von den Lungen-6 level 5 months after diagnosis in one patient; the other patient received tofacitinib 4 months after diagnosis to reduce ferritin levels and skin manifestations. Subsequently, both patients achieved remission, and prednisolone was withdrawn. Tofacitinib reduced the interferon signature associated with dermatomyositis/JDM disease progression and exerted a therapeutic effect on dermatomyositis/JDM. We found six published cases from five articles of tofacitinib for refractory anti-MDA5 Ab + JDM. Except for one case of herpes simplex meningitis, the other cases, including ours, had improved disease activity without severe adverse events, and steroids and immunosuppressive medicines could be tapered. Tofacitinib could be considered an available therapy for refractory anti-MDA5 Ab + JDM.

A comprehensive review of dermatomyositis treatments - from rediscovered classics to promising horizons

INTRODUCTION

Dermatomyositis (DM) is a rare inflammatory disease with diverse cutaneous and systemic manifestations, often associated with myositis-specific antibodies. Managing patients with refractory DM, or individuals presenting pecific complications, like calcinosis or rapidly progressive interstitial lung disease, presents unique challenges.

AREAS COVERED

This review explores current and promising treatment options for DM, drawing from clinical studies, case series, and case reports that consider the underlying disease pathophysiology.

EXPERT OPINION

Recent advancements have improved our understanding and management of DM. The discovery of distinct DM autoantibodies and their correlation with specific clinical phenotypes has transformed patient categorization and enhanced our knowledge of the pathogenesis of the disease. Intravenous immunoglobulin, a well-established treatment in dermatomyositis, has regained prominence and a large randomized clinical trial has reaffirmed its efficacy, confirming it as an effective therapeutic option in this group of patients. Identification of the type I interferon pathway as a key pathogenic mechanism in DM has opened up new avenues for more effective treatment strategies. Blocking the JAK/STAT pathway offers potential for improved management of refractory patients and prevention of highly morbid complications. These recent advancements have significantly impacted the management and care of dermatomyositis patients, enabling tailored approaches, targeted interventions, and improved outcomes for individuals affected by this complex condition.

Biologic drugs in the treatment of juvenile dermatomyositis: a literature review

There is no clear consensus in the literature regarding the choice of biologic therapies and efficacy in juvenile dermatomyositis (JDM). In this review, we aimed to examine previous studies regarding biologic drug use in JDM patients. We screened MEDLINE and Scopus for articles involving JDM patients treated with biologic drugs. We identified 74 articles describing 495 JDM patients treated with biologic drugs (538 biologic treatments) during our literature search. The median (min-max) age of these patients was 9.8 (1-17) years (F/M:1.8). The most frequently used biologic drugs were rituximab (RTX, 50%) and tumor necrosis factor (TNF) inhibitors (34.8%). In a few cases, abatacept (4.3%), anti-interleukin-1 agents (0.9%), tocilizumab (0.9%), bortezomib (0.4%), ustekinumab (0.2%), eculizumab (0.2%), and golimumab (0.2%) were used. RTX was most frequently preferred in patients with severe skin involvement (46.3%). Improvement with RTX was obtained in 60.1% of RTX treatments. Infliximab was most frequently preferred in calcinosis (43.3%), while adalimumab in skin involvement (50%) and etanercept in resistant/recurrent diseases (80%). Improvement was achieved in 44.4% of anti-TNF treatments. Adverse events were observed in 46.8% (58/124) of all treatments. Our results suggest that biologic agents may be a promising alternative for the treatment of particularly resistant JDM cases. Controlled studies are required to provide higher level of evidence for the timing of biologic use in JDM treatment. Key Points • There is no consensus on the choice and efficacy of biologic therapies in JDM. • RTX and TNF inhibitors are the most commonly used biologic drugs. • Biologics were especially preferred in severe skin involvement, calcinosis, and resistant diseases.

Calcinosis in juvenile dermatomyositis: Updates on pathogenesis and treatment

Calcinosis, or the deposition of insoluble calcium salts in the skin, subcutaneous tissue, fascia, tendons, and muscles, is a feared complication of juvenile dermatomyositis. Calcinosis is estimated to affect up to 40% of patients with juvenile dermatomyositis and contributes to significant disease morbidity. Calcinosis can be challenging to treat, and the most effective treatment remains unknown because of a lack of comparative studies. We aim to review the literature published in the last 5 years to summarize updates on the pathogenesis and treatment of calcinosis in juvenile dermatomyositis and describe future areas for research.

Update on dermatomyositis

PURPOSE OF REVIEW

This review summarizes and comments on current knowledge in dermatomyositis.

RECENT FINDINGS

The 2018 European Neuromuscular Centre classification of dermatomyositis has been challenging by the discovery of clinicopathological features associated with dermatomyositis-specific antibody (DMSA) that were not incorporated in the original criteria. These features include but may not be limited to the presence of perifascicular necrosis in anti-Mi-2 dermatomyositis; presence of diffuse nonperifascicular sarcoplasmic myxovirus resistance protein A expression in anti-MDA5 dermatomyositis; and dermatomyositis sine dermatitis in anti-NXP-2 dermatomyositis. Variations and subclassifications within the same DMSA subtypes are observed: anti-MDA5 dermatomyositis is clinically subcategorized into good, intermediate, and poor prognostic subgroups; concurrent anti-CCAR1 and anti-TIF1-γ positivity identify anti-TIF1-γ-positive patient with a lower risk for cancer-associated myositis. Owing to distinct IFN1-signaling pathway activation in dermatomyositis, JAK-STAT inhibitor - the pathway-targeted therapy, have been studied with promising results in refractory dermatomyositis and some new-onset dermatomyositis. In addition, the potential serum biomarkers for IFN1 pathway activation are being investigated for their performance in monitoring the disease activity and the efficacy of the treatment.

SUMMARY

DMSA, evidence of prominent IFN1 pathway activation, and risk/severity-associated biomarkers would likely play major roles in future dermatomyositis classification, disease monitoring, and treatment decision.

Advancements in the Treatment of Cutaneous Lupus Erythematosus and Dermatomyositis: A Review of the Literature

Background

Cutaneous lupus erythematosus (CLE) and dermatomyositis (DM) are autoimmune diseases that present with a wide variety of cutaneous manifestations. In both cases, first-line therapy includes topical corticosteroids. Patients may present with more widespread disease requiring systemic treatments, including corticosteroids, traditional immunosuppressants, or antimalarials. Due to their complex nature, both CLE and DM remain difficult to treat and continue to cause significant distress to patients.

Objective

To summarize the most recent literature on the safety and efficacy of novel treatment modalities for CLE and DM.

Methods

A literature search was conducted on PubMed using search terms “(dermatomyositis) AND (treatment)” and “(cutaneous lupus) AND (treatment)”. Additional search terms included specific names of biologic agents, phosphodiesterase inhibitors (apremilast), and JAK inhibitors.

Results

JAK inhibitors, PDE-4 inhibitors, and biologics have shown promise in reducing cutaneous symptoms of both CLE and DM, including reduction in SLE Disease Activity Index 2000 (SLEDAI-2K), Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI), British Isles Lupus Assessment Group (BILAG), Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI), and Disease Activity Score (DAS).

Conclusion

While there have been recent advancements in the treatment for CLE and DM, further research and clinical trials are required to better elucidate which therapy is best for individual patients.

Calcinosis in dermatomyositis: Origins and possible therapeutic avenues

Calcinosis, insoluble calcium compounds deposited in skin and other tissues, is a crippling sequela of dermatomyositis. Prolonged disease associated with ongoing inflammation, ischemia, repetitive trauma, and certain autoantibodies are associated with calcinosis. Herein, we describe potential pathogenic mechanisms including the role of mitochondrial calcification. There are no widely effective treatments for calcinosis. We review available pharmacologic therapies for calcinosis including those targeting calcium and phosphorus metabolism; immunosuppressive/anti-inflammatory therapies; and vasodilators. Mounting evidence supports the use of various formulations of sodium thiosulfate in the treatment of calcinosis. Although the early institution of aggressive immunosuppression may prevent calcinosis in juvenile dermatomyositis, only limited data support improvement once it has developed. Minocycline can be useful particularly for lesions associated with surrounding inflammation. Powerful vasodilators, such as prostacyclin analogs, may have promise in the treatment of calcinosis, but further studies are necessary. Surgical removal of lesions when amenable is our treatment of choice.

[Recent research on tofacitinib in the treatment of pediatric rheumatic diseases]

Tofacitinib is a Janus kinase inhibitor and can block the Janus kinase-signal transducer and activator of transcription signal transduction pathway and reduce the production and release of a variety of cytokines. It has great potential in the treatment of various rheumatic diseases with a rapid onset of action and can reduce corticosteroid dependence and related adverse events. The therapeutic effect of tofacitinib in adult patients has been confirmed, and it has been increasingly used in pediatric patients in recent years. This article reviews the clinical application of tofacitinib in the treatment of pediatric autoimmune diseases.

Evaluating the use of JAK inhibitors in inflammatory connective tissue diseases in pediatric patients: an update

INTRODUCTION

Connective tissue diseases (CTDs) are a category of conditions that affect tissues that support and provide structure to the body. These diseases include rheumatoid arthritis, systemic lupus erythematosus, dermatomyositis, and sclerosing diseases. CTDs can be caused by dysregulation of inflammatory pathways, specifically an upregulation of interferons and JAK/STAT pathway activation.

AREAS COVERED

While CTDs have historically been treated with broadly immunosuppressant medications such as corticosteroids and disease-modifying antirheumatic drugs (DMARDS), newer and more targeted immunomodulating medications called Janus kinase inhibitors (JAKi), have emerged as potential treatments.

EXPERT OPINION

While most studies regarding JAKi for CTDs have focused on adult populations, pediatric patients with CTDs may also benefit from JAKi therapy. Moreover, the JAK/STAT inhibitor tofacitinib has been approved by the FDA for the treatment of active polyarticular course juvenile idiopathic arthritis. In this review, we have summarized what has been published on the use of JAKi for various pediatric CTDs.

Emerging Therapeutics in the Management of Connective Tissue Disease. Part II. Dermatomyositis and Scleroderma

The management of connective tissue diseases is dramatically evolving with the advent of biologics and novel oral systemic therapeutics. Despite involvement in the care of these complex patients, there is a knowledge gap in the field of dermatology regarding these emerging agents. The second article in this continuing medical education series discusses new and emerging therapeutics for dermatomyositis and scleroderma that target cells, intracellular signaling pathways, and cytokines.

Updates on interferon in juvenile dermatomyositis: pathogenesis and therapy

PURPOSE OF REVIEW

This review provides updates regarding the role of interferon (IFN) in juvenile dermatomyositis (JDM), including comparison to interferonopathies and therapeutic implications.

RECENT FINDINGS

Transcriptomic and protein-based studies in different tissues and peripheral IFN-α assessment have demonstrated the importance of the dysregulated IFN pathway in JDM. Additional studies have validated IFN-regulated gene and protein expression correlation with disease activity in blood and muscle, with potential to predict flares. Type I and II IFN both are dysregulated in peripheral blood and muscle, with more type I IFN in skin. Muscle studies connects hypoxia to IFN production and IFN to vascular dysfunction and muscle atrophy. JDM overlaps with interferonopathy phenotype and IFN signature. There are multiple case reports and case series noting decreased IFN markers and clinical improvement in refractory JDM with Janus kinase (JAK) inhibitors.

SUMMARY

Studies confirm IFN, particularly type I and II IFN, is an important part of JDM pathogenesis by the level of dysregulation and correlation with disease activity, as well as IFN recapitulating key JDM muscle pathology. Smaller studies indicate there may be differences by myositis-specific autoantibody group, but validation is needed. JAK inhibitors are a promising therapy as they can inhibit IFN signaling, but further study is needed regarding which patients will benefit, dosing, and safety monitoring.

Juvenile Dermatomyositis: Advances in Pathogenesis, Assessment, and Management

BACKGROUND

Juvenile dermatomyositis is the most common inflammatory myopathy in the pediatric age group and a major cause of mortality and morbidity in individuals with childhood rheumatic diseases. Mounting evidence suggests that early diagnosis and timely aggressive treatment are associated with better outcomes.

OBJECTIVE

The purpose of this article is to provide readers with an update on the evaluation, diagnosis, and the treatment of juvenile dermatomyositis.

METHODS

A PubMed search was performed in Clinical Queries using the key term "juvenile dermatomyositis" in the search engine. The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews. The search was restricted to English literature. The information retrieved from the above search was used in the compilation of the present article.

RESULTS

Juvenile dermatomyositis is a chronic autoimmune inflammatory condition characterized by systemic capillary vasculopathy that primarily affects the skin and muscles with possible involvement of other organs. In 2017, the European League Against Rheumatism (EULAR) and the American College of Rheumatology (ACR) developed diagnostic criteria for juvenile idiopathic inflammatory myopathies and juvenile dermatomyositis. In the absence of muscle biopsies which are infrequently performed in children, scores (in brackets) are assigned to four variables related to muscle weakness, three variables related to skin manifestations, one variable related to other clinical manifestations, and two variables related to laboratory measurements to discriminate idiopathic inflammatory myopathies from non-idiopathic inflammatory myopathies as follows: objective symmetric weakness, usually progressive, of the proximal upper extremities (0.7); objective symmetric weakness, usually progressive, of the proximal lower extremities (0.8); neck flexors relatively weaker than neck extensors (1.9); leg proximal muscles relatively weaker than distal muscles (0.9); heliotrope rash (3.1); Gottron papules (2.1); Gottron sign (3.3); dysphagia or esophageal dysmotility (0.7); the presence of anti-Jo-1 autoantibody (3.9); and elevated serum levels of muscle enzymes (1.3). In the absence of muscle biopsy, a definite diagnosis of idiopathic inflammatory myopathy can be made if the total score is ≥7.5. Patients whose age at onset of symptoms is less than 18 years and who meet the above criteria for idiopathic inflammatory myopathy and have a heliotrope rash, Gottron papules or Gottron sign are deemed to have juvenile dermatomyositis. The mainstay of therapy at the time of diagnosis is a high-dose corticosteroid (oral or intravenous) in combination with methotrexate.

CONCLUSION

For mild to moderate active muscle disease, early aggressive treatment with high-dose oral prednisone alone or in combination with methotrexate is the cornerstone of management. Pulse intravenous methylprednisolone is often preferred to oral prednisone in more severely affected patients, patients who respond poorly to oral prednisone, and those with gastrointestinal vasculopathy. Other steroid-sparing immunosuppressive agents such as cyclosporine and cyclophosphamide are reserved for patients with contraindications or intolerance to methotrexate and for refractory cases, as the use of these agents is associated with more adverse events. Various biological agents have been used in the treatment of juvenile dermatomyositis. Data on their efficacy are limited, and their use in the treatment of juvenile dermatomyositis is considered investigational.