Favorable rituximab response in patients with refractory idiopathic inflammatory myopathies

Effectiveness of generic tofacitinib in idiopathic inflammatory myositis (IIM)-a retrospective analysis from Indian Myositis Registry (MyoIN)

OBJECTIVES

Determine domain-based-outcomes and steroid-sparing efficacy of generic tofacitinib in IIM.

METHODS

This is a multicenter retrospective study wherein clinical phenotype, autoantibody profile, prior immunosuppressives, and outcomes at 3, 6, and 12 months were retrieved for IIM patients prescribed tofacitinib. Overall clinical response was assessed as complete or partial remission as per physician judgment. Changes in cutaneous and calcinosis domain were recorded as per physician global assessment (PGA), lung domain as per medical research council (MRC) dyspnea scale, and muscle strength by Manual Muscle Testing-8 (MMT-8).

RESULTS

Forty-two patients of IIM with mean age 38.7 ± 16 years; (76.2% (N = 32) women), median duration of illness 48 (19;88) months were included. Commonest indication for initiating tofacitinib was either for refractory or as steroid sparing for cutaneous domain (N = 25/42, 59.5%) followed by calcinosis (N = 16/42, 38%). Overall complete and/or partial remission was achieved in 23/37 (64.8%), 30/35 (85.7%), and 29/30 (96.6%) patients at 3, 6, and 12 months, respectively. At 12-month follow-up, there was a reduction in prednisolone dose, with absolute decrease from a daily dose of 17.5 mg (IQR 5;50) to 2.5 mg (IQR 0;5) (p < 0.001). Individual domain assessments revealed improvement in cutaneous domain [16/25 (64%)] and calcinosis [6/15 (40%)]. Adverse effects included herpes zoster (N = 2/42, 4.8%) and dyslipidemia (N = 4/42, 9.5%).

CONCLUSIONS

Treatment with generic tofacitinib significantly reduces the daily dose of corticosteroids and is effective in cutaneous domain including calcinosis in IIM.

KEY POINTS

• This multicenter retrospective study is the first real-world data from India, elucidating steroid sparing efficacy of generic tofacitinib in patients with inflammatory myositis. • Domain-based outcome assessment suggests good clinical improvement especially in cutaneous domain, even those with refractory disease. • Modest benefits were evident in calcinosis, but its effect on the muscle and pulmonary domain appears limited.

Rituximab in the treatment of progressive interstitial lung disease associated with the antisynthetase syndrome

OBJECTIVE

To assess the real-world, long-term effectiveness of rituximab (RTX) as a rescue therapy in patients with antisynthetase syndrome and progressive interstitial lung disease (ASS-ILD).

METHODS

Multicentre observational retrospective longitudinal study of a cohort of patients with ASS-ILD that started treatment with RTX due to recurrent or ongoing progressive ILD despite therapy with glucocorticoids and immunosuppressants.

RESULTS

Twenty-eight patients were analyzed. Examining the entire study population, before treatment with RTX the mean decline in %pFVC and %pDLCO from the ASS-ILD diagnosis to the initiation of RTX treatment (T0) was -6.44% and -14.85%, respectively. After six months of treatment, RTX reversed the decline in pulmonary function test (PFT) parameters: ∆%pFVC +6.29% (95% CI: -10.07 to 2.51; p=0.002 compared to T0) and ∆%pDLCO +6.15% (95% CI: -10.86 to -1.43; p=0.013). Twenty-four patients completed one year of therapy and 22 two years, maintaining the response in PFT: ∆%pFVC: +9.93% (95% CI: -15.61 to -4.25; p=0.002) and ∆%pDLCO: +7.66% (95% CI: -11.67 to -3.65; p<0.001). In addition, there was a significant reduction in the median dose of prednisone, and it could be suspended in 18% of cases. In 33% of patients who required oxygen therapy at the start of treatment, it could be discontinued. The frequency of adverse events reached 28.5% of cases.

CONCLUSION

Based on our results, RTX appears to be effective as rescue therapy in most patients with recurrent or progressive ASS-ILD unresponsive to conventional treatment. The use of RTX was well tolerated in the majority of patients.

TCRβ clones in muscle tissue share structural features in patients with idiopathic inflammatory myopathy and are associated with disease activity

Objectives

To characterize the T cell receptor (TCRβ) repertoire in peripheral blood and muscle tissues of treatment naïve patients with newly diagnosed idiopathic inflammatory myopathies (IIMs).

Methods

High throughput RNA sequencing of the TCRβ chain was performed in peripheral blood and muscle tissue in twenty newly-diagnosed treatment-naïve IIM patients (9 DM, 5 NM/OM, 5 IMNM and 1 ASyS) and healthy controls. Results thereof were correlated with markers of disease activity.

Results

Muscle tissue of IIM patients shows more expansion of TCRβ clones and decreased diversity when compared to peripheral blood of IIM as well as healthy controls (both p=0.0001). Several expanded TCRβ clones in muscle are tissue restricted and cannot be retrieved in peripheral blood. These clones have significantly longer CDR3 regions when compared to clones (also) found in circulation (p=0.0002), while their CDR3 region is more hydrophobic (p<0.01). Network analysis shows that clonal TCRβ signatures are shared between patients. Increased clonal expansion in muscle tissue is significantly correlated with increased CK levels (p=0.03), while it tends to correlate with decreased muscle strength (p=0.08).

Conclusion

Network analysis of clones in muscle of IIM patients shows shared clusters of sequences across patients. Muscle-restricted CDR3 TCRβ clones show specific structural features in their T cell receptor. Our results indicate that clonal TCRβ expansion in muscle tissue might be associated with disease activity. Collectively, these findings support a role for specific clonal T cell responses in muscle tissue in the pathogenesis of the IIM subtypes studied.

Idiopathic inflammatory myopathies - The burden of disease: Cohort analysis focusing on damage and comorbidities

INTRODUCTION/BACKGROUND

Idiopathic Inflammatory Myopathies (IIM) continue to be a major clinical challenge worldwide. The exact aetiopathogenesis of this chronic and disabling disease remains elusive, preventing the development of novel and effective therapeutic strategies and leading to a high incidence of damage. The complexity of treating these diseases is even greater due to the numerous comorbidities that affect these patients.

METHODS

Retrospective review of the cohort of patients diagnosed with IIM and followed in a dedicated unit of a tertiary hospital between 1971 and December 2022, with particular attention to damage and comorbidities. Damage was assessed using the Myositis Damage Index. Comorbidities were recorded and analysed as a whole and also assessed using the Charlson Comorbidity Index. Health Assessment Questionnaire (HAQ) Disability Index (DI) was performed by phone call in December 2022, to all patients actively followed-up in the Unit.

RESULTS

Analysis of 149 patients with a mean follow-up of 9 years (range 0-51) revealed >90% with damage and comorbidities. Most comorbidities were a consequence of the damage and were particularly related to prolonged steroid therapy. Cardiovascular damage, which occurred either as cardiovascular risk factors or as end-organ sequelae (cardiovascular disease and chronic kidney disease), was the main cause and a major contributor to death. Depression was also high on the list of associated comorbidities. Median HAQ was 2.09 representing high negative impact in quality of life.

CONCLUSIONS

Although survival rates have increased in recent decades, patients with IIM carry a high burden of disease with poor quality of life, mainly caused by damage and comorbidities. While comorbidities accumulation is the major factor for poor quality of life, damage severity is the main predictor for mortality. Improved therapeutic strategies are needed to reduce the need for steroids and to introduce routine screening and management of comorbidities as an essential partner of immunosuppressive therapy, leading to comprehensive care of myositis patients and effective improvement of their quality of life.

Muscle glycome in idiopathic inflammatory myopathies: Impact in IL-6 production and disease prognosis

Idiopathic inflammatory myopathies (IIM) are a group of chronic autoimmune diseases mainly affecting proximal muscles. Absence of meaningful prognostic factors in IIM has hindered new therapies development. Glycans are essential molecules that regulate immunological tolerance and consequently the onset of autoreactive immune response. We showed that muscle biopsies from patients with IIM revealed a deficiency in the glycosylation pathway resulting in loss of branched N-glycans. At diagnosis, this glycosignature predicted disease relapse and treatment refractoriness. Peripheral CD4⁺ T cells from active-disease patients shown a deficiency in branched N-glycans, linked to increased IL-6 production. Glycan supplementation, restoring homeostatic glycosylation profile, led to a decrease in IL-6 levels. This study highlights the biological and clinical importance of glycosylation in IIM immunopathogenesis, providing a potential mechanism for IL-6 production. This pinpoints muscle glycome as promising biomarker for personalized follow-up and a potential target for new therapies in a patients' subgroup with an ominous evolution.

[Research advances in pharmacotherapy for rare diseases in children]

There are more than 7 000 rare diseases and approximately 475 million individuals with rare diseases globally, with children accounting for two-thirds of this population. Due to a relatively small patient population and limited financial resources allocated for drug research and development in pharmaceutical enterprises, there are still no drugs approved for the treatment of several thousands of these rare diseases. At present, there are no drugs for 95% of the patients with rare diseases, and consequently, the therapeutic drugs for rare diseases have been designated as orphan drugs. In order to guide pharmaceutical enterprises to strengthen the research and development of orphan drugs, various nations have enacted the acts for rare disease drugs, promoted and simplified the patent application process for orphan drugs, and provided scientific recommendations and guidance for the research and development of orphan drugs. Since there is a relatively high incidence rate of rare diseases in children, this article reviews the latest research on pharmacotherapy for children with rare diseases.

B-cell receptor profiling before and after IVIG monotherapy in newly diagnosed idiopathic inflammatory myopathies

OBJECTIVE

To unravel B-cell receptor (BcR) characteristics in muscle tissues and peripheral blood and gain more insight into BcR repertoire changes in peripheral blood in idiopathic inflammatory myopathies (IIMs), and study how this correlates to the clinical response to IVIG.

METHODS

Nineteen treatment-naive patients with newly diagnosed IIM were prospectively treated with IVIG monotherapy. RNA-based BcR repertoire sequencing was performed in muscle biopsies collected before, and in peripheral blood (PB) collected before and nine weeks after IVIG treatment. Results were correlated to patients' clinical improvement based on the total improvement score (TIS).

RESULTS

Prior to IVIG treatment, BcR clones found in muscle tissue could be retrieved in peripheral blood. Nine weeks after IVIG treatment, new patient-specific dominant BcR clones appeared in peripheral blood while pre-treatment dominant BcR clones disappeared. The cumulative frequency of all dominant BcR clones before treatment was significantly higher in individuals who responded to IVIG compared with those who did not respond to IVIG, and correlated with a higher CK. During follow-up, a decrease in the cumulative frequency of all dominant clones correlated with a higher TIS.

CONCLUSION

In treatment-naive patients with newly diagnosed IIM, muscle tissue and peripheral blood share expanded BcR clones. In our study a higher cumulative frequency of dominant BcR clones in blood before treatment was associated with a higher CK and better treatment response, suggesting that response to IVIG may depend on the composition of the pre-treatment BcR repertoire.

Low-dose rituximab is efficacious in refractory idiopathic inflammatory myopathies

OBJECTIVES

Rituximab (RTX) use early in the course of refractory idiopathic inflammatory myopathy (IIM) is not well studied. This study sought to determine the short-term efficacy of RTX in a registry-based cohort of refractory IIM.

METHODS

Registry-based observational data about IIM patients receiving RTX between 2018 and 2021 were included. Total improvement score was calculated from the core set measures as per International Myositis Assessment and Clinical Studies group (IMACS) at baseline, 6 months and 12 months of follow-up.

RESULTS

Forty-two patients (F:M, 29:13), with a mean (s.d.) age of 39.5 (11.5) years were studied. Majority of patients received RTX for refractory myositis, after a median (interquartile range) duration of 8 (4,18) months. Twenty-eight received RTX at a dosage of 1 g × two doses, while 14 received 500 mg × two doses with an interval of 15 days. At 6 months and 12 months post-RTX, the improvement was recorded in manual muscle testing (MMT-8) scores, physician global assessment (PGA), patient global assessment (PtGA) and median steroid dosage as compared with the baseline (P < 0.01 for all). A mean (s.d.) improvement of 44.5 (16) and 48.7 (19.2) in total improvement score was recorded at 6 and 12 months, respectively. The change in MMT-8, PGA and PtGA scores from baseline between the two dosage regimens of RTX were comparable at 6 and 12 months. Severe lower respiratory tract infections requiring hospitalization occurred in three patients of the cohort.

CONCLUSION

RTX improved IMACS core set measures and had steroid sparing efficacy at 6 and 12 months in patients with IIM in this registry-based study. Rituximab as an induction regimen of two doses of 500 mg can be as efficacious as 1 g at 6 months and 12 months of follow-up.

Efficacy and safety of rituximab treatment in patients with idiopathic inflammatory myopathies: A systematic review and meta-analysis

Objective

Idiopathic inflammatory myopathies (IIMs) are a heterogeneous group of autoimmune diseases with various subtypes, myositis-specific antibodies, and affect multiple systems. The treatment of IIMs remains challenging, especially for refractory myositis. In addition to steroids and traditional immunosuppressants, rituximab (RTX), a B cell-depleting monoclonal antibody, is emerging as an alternative treatment for refractory myositis. However, the therapeutic response to RTX remains controversial. This meta-analysis aimed to systematically evaluate the efficacy and safety of RTX in patients with IIMs, excluding sporadic inclusion body myositis.

Methods

PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, and WanFang Data were searched for relevant studies. The overall effective rate, complete response rate, and partial response rate were calculated to assess the efficacy of RTX. The incidences of adverse events, infection, severe adverse events, severe infection, and infusion reactions were collected to evaluate the safety of RTX. Subgroup analyses were performed using IIM subtypes, affected organs, continents, and countries. We also performed a sensitivity analysis to identify the sources of heterogeneity.

Results

A total of 26 studies were included in the quantitative analysis, which showed that 65% (95% confidence interval [CI]: 54%, 75%) of patients with IIMs responded to RTX, 45% (95% CI: 22%, 70%) of patients achieved a complete response, and 39% (95% CI: 26%, 53%) achieved a partial response. Subgroup analyses indicated that the overall efficacy rates in patients with refractory IIMs, dermatomyositis and polymyositis, as well as anti-synthetase syndrome were 62%, 68%, and 62%, respectively. The overall efficacy rates for muscle, lungs, and skin involvement were 59%, 65%, and 81%, respectively. In addition, studies conducted in Germany and the United States showed that patients with IIMs had an excellent response to RTX, with an effective rate of 90% and 77%, respectively. The incidence of severe adverse events and infections was 8% and 2%, respectively.

Conclusion

RTX may be an effective and relatively safe treatment choice in patients with IIMs, especially for refractory cases. However, further verification via randomized controlled trials is warranted.

A novel estrogen receptor 1-sphingomyelin phosphodiesterase acid like 3B pathway mediates rituximab response in myositis patients

OBJECTIVES

The B cell depleting biologic, rituximab, is used to treat refractory autoimmune myositis. However, the beneficial effects of rituximab appear to outweigh the known contribution of B-cells in myositis. We aimed to elucidate how myositis patients respond differently to rituximab and possible alternative mechanisms of action.

METHODS

Here we have: a) comprehensively investigated concurrent mRNA and microRNA expression in muscle biopsies taken at baseline and 16 weeks post treatment in ten patients who were part of the rituximab in myositis (RIM) trial; and b) investigated the beneficial effect of rituximab on myositis muscle cells.

RESULTS

Our analyses identified an increased number of changes in gene expression in biopsies from patients who had a clinical response to rituximab (n = 5) compared with non-responders (n = 5). The two groups had completely different changes in microRNA and mRNA expression following rituximab therapy, with the exception of one mRNA, BHMT2. Networks of mRNA and microRNA with opposite direction of expression changes highlighted ESR1 as upregulated in responders. We confirmed ESR1 upregulation upon rituximab treatment of immortalized myotubes and primary human dermatomyositis muscle cells in vitro, demonstrating a direct effect of rituximab on muscle cells. Notably, despite showing a response to rituximab, human dermatomyositis primary muscle cells did not express the rituximab target, CD20. However, these cells expressed a possible alternative target of rituximab, sphingomyelinase-like phosphodiesterase 3 b (SMPDL3B).

CONCLUSION

In addition to B cell depletion, rituximab may be beneficial in myositis due to increased ESR1 signalling mediated by rituximab binding to SMPDL3B on skeletal muscle cells.

Pathophysiological Mechanisms and Treatment of Dermatomyositis and Immune Mediated Necrotizing Myopathies: A Focused Review

Idiopathic inflammatory myopathies (IIM), collectively known as myositis, are a composite group of rare autoimmune diseases affecting mostly skeletal muscle, although other organs or tissues may also be involved. The main clinical feature of myositis is subacute, progressive, symmetrical muscle weakness in the proximal arms and legs, whereas subtypes of myositis may also present with extramuscular features, such as skin involvement, arthritis or interstitial lung disease (ILD). Established subgroups of IIM include dermatomyositis (DM), immune-mediated necrotizing myopathy (IMNM), anti-synthetase syndrome (ASyS), overlap myositis (OM) and inclusion body myositis (IBM). Although these subgroups have overlapping clinical features, the widespread variation in the clinical manifestations of IIM suggests different pathophysiological mechanisms. Various components of the immune system are known to be important immunopathogenic pathways in IIM, although the exact pathophysiological mechanisms causing the muscle damage remain unknown. Current treatment, which consists of glucocorticoids and other immunosuppressive or immunomodulating agents, often fails to achieve a sustained beneficial response and is associated with various adverse effects. New therapeutic targets have been identified that may improve outcomes in patients with IIM. A better understanding of the overlapping and diverging pathophysiological mechanisms of the major subgroups of myositis is needed to optimize treatment. The aim of this review is to report on recent advancements regarding DM and IMNM.

Antibody Therapies in Autoimmune Inflammatory Myopathies: Promising Treatment Options

Inflammatory myopathies, including polymyositis (PM), dermatomyositis (DM), inclusion body myositis (IBM), necrotizing myopathy (NM), antisynthetase syndrome (ASS) and overlap myositis (OM), in short myositis, are rare diseases. All forms of myositis have progressive muscle weakness in common, with each subtype characterized by different autoantibody profiles, histological findings and extramuscular manifestations. Due to better understanding of the pathogenesis of the muscle inflammation in myositis, new molecular pathways for targeted therapy have been discovered. Current therapies aim at different components of the innate or the adaptive immune response. Additionally, non-inflammatory mechanisms in myositis have come into focus as possible treatment targets. The use of therapeutical antibodies in myositis has been examined in various clinical studies, several of them randomized controlled ones: Depletion of B-cells by rituximab has been established as treatment of refractory myositis. IVIG, an antibody therapy in the wider sense, has now been licensed for DM following a recent positive clinical trial. Negative study results were reported in randomized trials with infliximab, sifalimumab and bimagrumab. Studies on basiliximab and eculizumab are currently underway, and are expected to yield results in a couple of years. Despite some promising results of clinical studies with antibody therapy in myositis, further research is crucial to optimize the treatment for this debilitating disease and to find treatment alternatives for treatment-refractory patients.

[Long-term rituximab treatment of refractory idiopathic inflammatory myopathy: A report of 3 cases]

Idiopathic inflammatory myopathies are a group of rare but serious diseases. The treatment of refractory idiopathic inflammatory myopathy is always challenging, especially in children. Three cases of refractory idiopathic inflammatory myopathy treated by rituximab were reported and discussed with the review of relevant literature. All were female with on-set age of 8 years and 6 months, 11 years and 7 months, 4 years and 2 months old, respectively. All had acute onset, presenting with progressive and severe muscle weakness. All lost ambulation within 1 or 2 months, with difficult swallowing and low voice. Respiratory distress occurred in case 2 after an attack of asphyxia due to an aspiration of sputum, and ventilator support was required for 1 month. Rashes were detected at the initial stage of the disease in cases 2 and 3. Patient 2 showed facial erythematous papules, spreading to her neck and hands. Patient 3 showed purplish eyelids with peri-orbital swelling, generalized edema involving all her limbs. Creatine kinase (CK) levels were markedly elevated in all the patients, ranging from 6 000 IU/L to 28 819 IU/L. Anti-SRP antibody was identified in cases 1, and anti-NXP2 antibodies were confirmed in cases 2 and 3. MRI of both thighs in all the patients showed profound muscle and fascial edema. Muscle pathology of patient 1 showed prominent fiber variation and endomysial fibrosis, with overexpression of MHC-Ⅰ. While muscle pathology in patients 2 and 3 showed scattered fiber necrosis, regeneration, endomysial edema without inflammatory cell infiltration. All the patients were diagnosed with idiopathic inflammatory myopathy and failed to the initial treatment including adequate glucocorticoids and high-dose immunoglobulin therapy. Other immunosuppressants (methotrexate, cyclophosphamide) were also tried in cases 2 and 3 with poor response. Then all the patients were treated with rituximab combined with glucocorticoids. Patient 1 regained normal strength and discontinued rituximab at the end of her last follow-up (2 years and 7 mouths). Though calcinosis developed during the follow-up period, significant improvement was noticed in cases 2 and 3 (both regained the ability to walk independently) at the end of their last follow-up after 2 years and 8 months, 3 years and 2 months respectively. Long-term rituximab therapy may improve the prognosis of refractory idiopathic inflammatory myopathy, especially with positive anti-SRP and anti-NXP2 antibodies.

Update on Myositis Therapy: from Today's Standards to Tomorrow's Possibilities

Inflammatory myopathies, in short, myositis, are heterogeneous disorders that are characterized by inflammation of skeletal muscle and weakness of arms and legs. Research over the past few years has led to a new understanding regarding the pathogenesis of myositis. The new insights include different pathways of the innate and adaptive immune response during the pathogenesis of myositis. The importance of non-inflammatory mechanisms such as cell stress and impaired autophagy has been recently described. New target-specific drugs for myositis have been developed and are currently being tested in clinical trials. In this review, we discuss the mechanisms of action of pharmacological standards in myositis and provide an outlook of future treatment approaches.

Therapieoptionen und outcome bei idiopathischen entzündlichen Muskelerkrankungen

Die idiopathischen entzündlichen Muskelerkrankungen (IIM) sind eine sehr heterogene Gruppe, die sich immer besser differenzieren lässt. Damit eröffnen sich mehr Möglichkeiten für gezieltere Therapien, die zum einen auf die Veränderung pathogenetischer Faktoren gerichtet sind. Zum anderen sollen sie Krankheitsaktivität vermindern, Muskelaufbau fördern, Organschäden verhindern und Lebensqualität verbessern.

Die folgende Übersichtsarbeit fasst die vorhandenen Daten zu bereits angewandten Behandlungen in der Praxis zusammen und gibt einen Ausblick auf zukünftige Alternativen.

Für die Polymyositis (PM) und Dermatomyositis (DM) sind Glukokortikoide weiter unverzichtbarer Therapiebestandteil. Eine frühe Kombination mit konventionellen DMARDs hat sich durchgesetzt. Die ProDerm- Studie stellt für die Immunglobulintherapie in der Praxis eine gute Basis dar. Rituximab (RTX) löst Cyclophosphamid (CYC) bei schweren Verlaufsformen immer mehr ab.

Für Abatacept, Jak-Kinase-Hemmer, Apremilast, Sifalimumab und Lenabasum müssen vielversprechende erste Ergebnisse durch weiter Studien untermauert werden. Anspruchsvoll ist die Behandlung bei extramuskulärer Beteiligung. Von großem Interesse ist der zukünftige Stellenwert von Nintedanib bei der interstitiellen Lungenerkrankung im Rahmen einer Myositis (IIM-ILD).

Die Therapie der Einschlusskörperchen- Myositis (IBM) ist immer noch eine große Herausforderung. Zahlreiche Studien haben bisher nicht überzeugend zu einer Besserung der Prognose führen können. Spätestens bei therapierefraktärem Verlauf sollte an eine Malignom- assoziierte Myositis gedacht werden. Gelegentlich verbirgt sich auch eine hereditäre Myopathie hinter einer, zum Beispiel durch einen Infekt oder Überlastung getriggerten, Myositis.

Komplikationen im Verlauf, wie Dysphagie, Infektionen, Myokardbeteiligung stellen keine Seltenheit dar. Häufig besteht Multimorbidität. Eine interdisziplinäre Zusammenarbeit in einem kompetenten Team, in dem erfahrene Physio-, Ergo- und Psychotherapeuten fester Bestandteil sind, ist unabdingbar für eine erfolgreiche Begleitung dieser Patienten.

Inflammatory Myositis in Cancer Patients Receiving Immune Checkpoint Inhibitors

OBJECTIVE

To estimate the incidence of immune checkpoint inhibitor-related myositis (ICI-myositis) in cancer patients receiving ICIs, and to report associated clinical manifestations, patterns of care, and outcomes.

METHODS

We identified a retrospective cohort of patients receiving ICIs between 2016 and 2019 seen at the University of Texas MD Anderson Cancer Center. Cases of ICI-myositis were identified using International Classification of Disease codes and confirmed by reviewing medical records and pathology, as available.

RESULTS

A total of 9,088 patients received an ICI. Thirty-six patients (0.40%) were identified as having ICI-myositis: 17 patients (47%) with ICI-myositis alone and 19 (53%) with overlap manifestations (5 patients with myocarditis, 5 with myasthenia gravis, and 9 with both). The incidence of ICI-myositis was 0.31% in those receiving ICI monotherapy and 0.94% in those receiving combination ICI therapy (relative risk 3.1 [95% confidence interval 1.5-6.1]). Twenty-five patients (69%) received ≥1 treatment in addition to glucocorticoids: plasmapheresis in 17 patients (47%), intravenous immunoglobulin in 12 (33%), and biologics in 11 (31%). Patients with overlap conditions had worse outcomes than those with myositis alone, and 79% of them developed respiratory failure. Eight patients died as a result of ICI-myositis, and all had overlap syndrome with myasthenia gravis or myocarditis (P < 0.05); 75% of these patients had a concomitant infection.

CONCLUSION

ICI-myositis is a rare but severe adverse event. More than half of the patients presented with overlap manifestations and had deleterious outcomes, including respiratory failure and death. None of the patients with ICI-myositis alone died as a result of adverse events. Optimal treatment strategies have yet to be determined.

Mycophenolate in idiopathic inflammatory myositis: outcome data of a large South Asian cohort

BACKGROUND

Consensus on treatment of idiopathic inflammatory myositis (IIM), particularly with regard to flares and interstitial lung disease (ILD), does not exist. We studied the long-term outcome and treatment response in our large, retrospective cohort of adult South-Asian patients exclusively with IIM.

METHODOLOGY

Electronic records of IIM patients satisfying inclusion and exclusion criteria were studied longitudinally at presentation, at 3, 6, 12, 18 and 24 months and thereafter yearly till their last follow up (F/u) visit. Depending on clinical, imaging, and muscle enzyme profile during the F/u period, patients were categorised as complete (CR) and partial responders (PRs). Parameters favouring CR were assessed using multivariate logistic regression analysis. Outcome parameters and flares on immunosuppressants (IS) were then assessed in patients with/without ILD.

RESULTS

Two hundred thirty-two patients with median F/u duration of 44.5 months (25-80.25) were included. ILD was seen in 40.1%. Patients with non-Jo1 anti-synthetase antibodies (n=26) were numerically more than those with Jo-1 antibody (n=24). CR status was attained by 50.9% patients. Absence of pericardial effusion (p=0.042, OR 4.223, 95% CI: 1.05-16.9) and presence of Gottron's rash (p=0.044, OR 1.78, 95% CI 1.017-3.121) at baseline predicted CR by multivariate regression. Majority received mycophenolate during the entire F/u period. Discontinuation of steroids was feasible in 51.7% after a median duration of 24 months (18-42). After excluding patients with ILD, flares were numerically lesser in patients only on mycophenolate compared with those only on methotrexate (p=0.06). Further flares were curtailed when switched from other agents to mycophenolate.

CONCLUSION

Mycophenolate is an effective treatment option in IIM patients with and without co-existing ILD. Presence of Gottron's rash and absence of pericardial effusion were found to be predictors of favourable clinical outcome in this largest single-centre study.

Antisynthetase syndrome: A distinct disease spectrum

The discovery of novel autoantibodies related to idiopathic inflammatory myopathies (collectively referred to as myositis) has not only advanced our understanding of the clinical, serological, and pathological correlation in the disease spectrum but also played a role in guiding management and prognosis. One group of the myositis-specific autoantibodies is anti-aminoacyl-tRNA synthetase (anti-ARS or anti-synthetase) which defines a syndrome with predominant interstitial lung disease, arthritis, and myositis. Autoantibodies to eight aminoacyl-tRNA synthetases have been identified with anti-Jo1 the most common in all of idiopathic inflammatory myopathies. Disease presentation and prognosis vary depending on which anti-aminoacyl-tRNA synthetase antibody is present. In this review, we will discuss the clinical characteristics, overlap features with other autoimmune diseases, prognostic factors, and management of the antisynthetase syndrome.

Efficacy and Safety of Rituximab in Korean Patients with Refractory Inflammatory Myopathies

BACKGROUND

Rituximab (RTX), a monoclonal antibody that selectively binds to CD20+ B cells, showed favorable outcomes in patients with idiopathic inflammatory myopathies (IIM) in small case series, but the evidence is still not enough. Our goal was to determine the efficacy and safety of RTX for Korean patients with refractory IIM.

METHODS

We retrospectively analyzed the medical records of 16 patients with refractory IIM treated with RTX in seven tertiary rheumatology clinics in the Korea. The efficacy of RTX was evaluated with the improvement of serum creatine phosphokinase (CPK) level and physician's global assessment (PGA), and daily corticosteroid dose reduction. A > 25% decrease in CPK level, corticosteroid dose, or PGA was considered significant. A complete response (CR) was designated by meeting three efficacy criteria and a partial response (PR) by only two criteria.

RESULTS

Sixteen patients with IIM were evaluated (13 female; median age, 51.8 years). All patients had received at least one conventional immunosuppressive agent (median, 3.6 [2.0-5.0]) and concomitant corticosteroids. The median CPK level and median dose of prednisolone was 421.0 units/L and 20.0 mg/day respectively. Eleven patients were treated with intravenous immunoglobulin. Seven patients received 2,000 mg of RTX and the others received lower dose. Twenty-four weeks after RTX treatment, 11 patients achieved a > 25% reduction in corticosteroid dose and CPK levels, and nine showed improved PGA. The overall response rate was 68.8% (11 patients). At the end of follow-up (median 24 weeks), 12 (75.0%) patients responded overall: four (25.0%) and eight (50.0%) patients achieved CR and PR, respectively. Baseline muscle enzyme levels were higher in responders than non-responders, but disease duration, RTX dose, ESR and serum CRP were not significantly different between the two groups. The rate of adverse event was 25.4/1,000 person-years.

CONCLUSION

RTX could be an effective and relatively safe therapeutic option in patients with refractory IIM.

A prospective cross-sectional study of serum IL-17A in antisynthetase syndrome

OBJECTIVES

The pro-inflammatory interleukin (IL)-17A serum has been characterized in several systemic autoimmune diseases, but not in antisynthetase syndrome (ASS). Therefore, the present study aims firstly to assess the serum level of the IL-17A in patients with ASS, comparing with healthy individuals, and secondly to analyze prospectively this IL in patients with refractory ASS undergoing rituximab treatment.

MATERIALS AND METHODS

A cross-sectional, single-center study that included 64 patients with ASS who were age-, gender-, and ethnicity-matched to 64 healthy individuals. Disease status was measured by the International Myositis Assessment and Clinical Studies Group (IMACS) set scores. Secondarily, the patients with refractory disease treated with rituximab were prospectively followed for 12 months. The IL-17A was assessed by the ELISA method.

RESULTS

The mean age of the patients was 44.8 ± 11.8 years, with a predominance of female gender and Caucasian. The median serum IL-17A level was higher in ASS patients compared with healthy individuals: 9.7 (9.1-10.4) vs. 7.7 (5.7-9.0) pg/mL, respectively, and P < 0.001. However, the demographical, clinical, and laboratory data indicates that disease status did not correlate with serum levels of the IL-17A in ASS patients. Prospectively, 16 patients received rituximab, and there was a drop of IL-17A serum level over the first year of treatment in these patients: from 9.7 (9.1-10.6) to 9.0 (8.2-9.7) pg/mL (P = 0.01).

CONCLUSIONS

Our study demonstrated that patients with ASS have increased serum levels of the IL-17A compared with healthy controls. In addition, the patients with refractory ASS treated with rituximab showed a reduction of the serum levels of the IL-17A. Key Points • Patients with ASS have increased serum levels of the IL-17A. • Patients with refractory ASS treated with rituximab showed a reduction of the serum levels of the IL-17A.

New insights into the treatment of myositis

The myositis syndromes include polymyositis, dermatomyositis (DM), necrotizing myopathy, inclusion body myositis (IBM), antisynthetase syndrome and overlap syndromes with myositis. These syndromes mostly occur in middle-aged patients, while juvenile DM occurs in children and adolescents. Patients mostly show a subacute weakness and myalgia in the upper and lower limbs, the diagnosis is based upon these clinical findings in combination with muscle biopsy results and specific serum autoantibodies. In recent years, research achieved a better understanding about the molecular mechanism underlying the myositis syndromes, as well as disease progress and extramuscular organ manifestations, such as interstitial lung disease and association with neoplasias. Treatment mainly consists of glucocorticosteroids and immunosuppressants. IBM is usually refractory to treatments. This review provides an overview of the current standards of treatment and new treatment options like monoclonal antibodies and new molecular therapies and their first results from clinical trials.

Recent Advances in Pharmacological Treatments of Adult Dermatomyositis

PURPOSE OF THE REVIEW

Dermatomyositis (DM) is an uncommon autoimmune disease that primarily affects the skin, muscle, and/or lungs, and remains a therapeutic challenge. We discuss recent studies evaluating efficacy of conventional treatments for clinically amyopathic DM (CADM), DM-associated interstitial lung (ILD) disease, and classic DM (CDM). We highlight several emerging new therapies with a focus on clinical trials, systematic reviews, and case series in the last 5 years.

RECENT FINDINGS

Recent studies report a significant number of patients remain refractory to antimalarials and require second- and third-line agents. Effective treatment for DM-associated ILD can vary based on patient specific antibodies. CDM requires oral glucocorticoids; recent studies have evaluated the benefits of adjunctive therapies including methotrexate and calcineurin inhibitors. New therapies target cell populations or cytokines thought to drive disease pathogenesis. Dermatomyositis is an autoimmune disease that remains challenging to treat. Many patients are refractory to conventional therapies, warranting the development and evaluation of new treatments.

Learning From Success and Failure: Biologics for Non-approved Skin Diseases

The impressive potential of biologics has been demonstrated in psoriasis, hidradenitis suppurativa, and urticaria. Numerous biologicals are entering the field for a restricted number of skin disorders. Off-label use of biologics in other recalcitrant skin diseases has increased. Mounting data point to the potential of already existing biologics acting on the IL-17/IL-23 pathway in skin disorders with epidermal hyperkeratosis (e.g., pityriasis rubra pilaris), acneiform inflammation (e.g., hidradenitis suppurativa), and loss of mucosal integrity (e.g., aphthosis). TNF-α blockers are also effective in the latter conditions but seem of particular value in granulomatous (e.g., granuloma annulare) and neutrophilic disorders (e.g., pyoderma gangrenosum). Failure of IL-17 blockade in skin diseases resulting from immune-mediated cell destruction (e.g., alopecia areata and vitiligo) illustrates its limited involvement in Th1-dependent skin immunology. Overall, disappointing results of TNF-α blockers in alopecia areata and vitiligo point to the same conclusion although promising results in toxic epidermal necrolysis suggest TNF-α exerts at least some in vivo Th1-related activities. Acting on both the Th1 and Th17 pathway, ustekinumab has a rather broad potential with interesting results in lupus and alopecia areata. The efficacy of omalizumab in bullous pemphigoid has revealed an IgE-mediated recruitment of eosinophils leading to bullae formation. Reconsidering reimbursement criteria for less common but severe diseases seems appropriate if substantial evidence is available (e.g., pityriasis rubra pilaris). For other disorders, investigator- and industry-initiated randomized clinical trials should be stimulated. They are likely to improve patient outcome and advance our understanding of challenging skin disorders.

Dermatomyositis: Diagnosis and treatment

The second article in this continuing medical education series reviews the initial evaluation of patients with suspected dermatomyositis (DM), the relevant work-up for malignancy and interstitial lung disease once a diagnosis of DM is made, and treatment recommendations for patients with DM based on disease severity, the presence of systemic symptoms, and myositis-specific antibody (MSA) profiles. This review emphasizes the emerging role of MSAs in the diagnosis of DM and highlights how MSAs can be used to guide the appropriate work-up for malignancy and interstitial lung disease. The treatment approach proposed by this continuing medical education series discusses both established and novel therapies for DM and highlights the importance of considering lesion type, degree of muscle involvement, presence of systemic symptoms, presence of MSAs, and patient age when determining the best treatment approach for a patient with DM.