A systematic review of clinical and preclinical evidences for Janus kinase inhibitors in large vessel vasculitis

Pediatric-onset Takayasu arteritis is associated with greater risk of mortality than adult-onset Takayasu arteritis-A systematic review with meta-analysis of observational cohort studies

A subset of Takayasu arteritis (TAK) has onset in the pediatric age group (≤18 years). The differences in mortality between pediatric-onset and adult-onset TAK are unclear. Therefore, we undertook a systematic review with meta-analysis to compare mortality risk in pediatric-onset with adult-onset TAK. Scopus, Pubmed (MEDLINE and Pubmed Central), recent conference abstracts, clinicaltrials.gov, and the Cochrane database were searched up to August 2023 for relevant studies. Five studies (all of moderate or high quality on the Newcastle Ottawa scale) were identified which had compared mortality between 151 pediatric-onset and 499 adult-onset TAK. Pediatric-onset TAK was associated with a significantly higher risk of death than adult-onset TAK (pooled risk ratio 2.27, 95% confidence interval 1.05 - 4.85, I2=0%). Cardiovascular disease and infections were the major causes of death in both pediatric-onset and adult-onset TAK. Sub-group analyses identified a greater mortality risk with pediatric-onset TAK in retrospective (but not prospective) studies and in studies of high quality (but not in those of moderate quality). Meta-regression did not reveal a significant influence of differences in sex distribution or age or the proportions of patients with pediatric-onset or adult-onset TAK on the pooled mortality risk. An increased mortality risk with pediatric-onset TAK on meta-analysis is consistent with more frequent severe organ manifestations of pediatric-onset TAK (heart failure, renal failure) when compared with adult-onset TAK. Future studies should systematically evaluate differences in the pathogenesis between pediatric-onset and adult-onset to understand the reasons for such observed differences in the mortality risk.

JAK inhibitors and black box warnings: what is the future for JAK inhibitors?

INTRODUCTION

Janus kinase inhibitors (JAKi) have dramatically improved the treatment of various autoimmune and myeloproliferative disorders. Recently, concern has arisen regarding their safety in patients with rheumatoid arthritis.

AREAS COVERED

Here, we provide a comprehensive summary of the major current and emerging JAKi and their indications, address recent studies on comparative safety, and provide insight into their future and use. We emphasize that the application of the research findings on a case-by-case basis should consider a patient's age, comorbidities, disease for which JAKi is being considered, disease activity, the JAKi target(s), alternate treatment options available for the patient, and the planned duration of JAKi.

EXPERT OPINION

Rheumatologists are used to prescribing therapies in which a risk-to-benefit assessment is required as well as to screening and monitoring the safety of medications. Thus, rheumatologists are already practiced in applying specific criteria to effectively screen and monitor patients who are candidates for JAKi therapy. Ongoing research will help to clarify any mechanisms underlying differential safety signals between JAK and other therapies, what the balance between risk and efficacy is, who the susceptible subpopulations are, and whether safety signals are shared between different JAKis and across indications.

Clinical experience and safety of Janus kinase inhibitors in giant cell arteritis: a retrospective case series from Sweden

The Janus kinase (JAK)-STAT signaling pathway is relevant in both Takayasu and giant cell arteritis (GCA), and the use of JAK inhibitors (JAKi) in arthritis, psoriasis, and inflammatory bowel disease is nowadays common. Some evidence of the clinical efficacy of JAKi in GCA exists and a phase III randomized controlled trial (RCT) of upadacitinib is currently recruiting. In 2017, we started using barcitinib in a GCA patient with inadequate response to corticosteroids, and later on, we treated other 14 GCA patients with baricitinib/tofacitinib during intense follow-up. The retrospective data of these 15 individuals are here summarized. GCA was diagnosed based on the ACR criteria and/or imaging techniques combined with increased C-reactive protein (CRP) and/or erythrocyte sedimentation rate (ESR) followed by a good initial response to corticosteroids. JAKi was initiated based on inflammatory activity, with increased CRP, presumably dependent on GCA with clinical symptoms, despite unsatisfying high doses of prednisolone. The mean age at JAKi initiation was 70.1 years and the mean exposure to JAKi was 19 months. From initiation, significant reductions in CRP were seen already at 3 (p = 0.02) and 6 (p = 0.02) months. A slower decrease was observed regarding ESR at 3 (p = 0.12) and 6 (p = 0.02) months. Furthermore, the daily prednisolone doses were reduced at 3 (p = 0.02) and 6 (p = 0.004) months. No GCA relapses were observed. Two patients were affected by serious infections, but JAKi therapy was retained or reintroduced after recovery. We present encouraging observational data on JAKi in GCA in one of the hitherto largest case series with long-term follow-up. Our clinical experiences will complement the results from the awaited RCT.

Arterial wall fibrosis in Takayasu arteritis and its potential for therapeutic modulation

Arterial wall damage in Takayasu arteritis (TAK) can progress despite immunosuppressive therapy. Vascular fibrosis is more prominent in TAK than in giant cell arteritis (GCA). The inflamed arterial wall in TAK is infiltrated by M1 macrophages [which secrete interleukin-6 (IL-6)], which transition to M2 macrophages once the inflammation settles. M2 macrophages secrete transforming growth factor beta (TGF-β) and glycoprotein non-metastatic melanoma protein B (GPNMB), both of which can activate fibroblasts in the arterial wall adventitia. Mast cells in the arterial wall of TAK also activate resting adventitial fibroblasts. Th17 lymphocytes play a role in both TAK and GCA. Sub-populations of Th17 lymphocytes, Th17.1 lymphocytes [which secrete interferon gamma (IFN-γ) in addition to interleukin-17 (IL-17)] and programmed cell death 1 (PD1)-expressing Th17 (which secrete TGF-β), have been described in TAK but not in GCA. IL-6 and IL-17 also drive fibroblast activation in the arterial wall. The Th17 and Th1 lymphocytes in TAK demonstrate an activation of mammalian target organ of rapamycin 1 (mTORC1) driven by Notch-1 upregulation. A recent study reported that the enhanced liver fibrosis score (derived from serum hyaluronic acid, tissue inhibitor of metalloproteinase 1, and pro-collagen III amino-terminal pro-peptide) had a moderate-to-strong correlation with clinically assessed and angiographically assessed vascular damage. In vitro experiments suggest the potential to target arterial wall fibrosis in TAK with leflunomide, tofacitinib, baricitinib, or mTORC1 inhibitors. Since arterial wall inflammation is followed by fibrosis, a strategy of combining immunosuppressive agents with drugs that have an antifibrotic effect merits exploration in future clinical trials of TAK.

Management of Takayasu arteritis

This review overviews the challenges in the assessment of disease activity, damage, and therapy of Takayasu arteritis (TAK). Recently developed disease activity scores for TAK are more useful for follow-up visits and require validation of cut-offs for active disease. A validated damage score for TAK is lacking. Computed tomography angiography (CTA), magnetic resonance angiography (MRA), and ultrasound enable the evaluation of vascular anatomy and arterial wall characteristics of TAK. 18-fluorodeoxyglucose (18-FDG) positron emission tomography (PET) visualizes arterial wall metabolic activity and complements the information provided by circulating C-reactive protein (CRP) levels. ESR and CRP alone moderately reflect TAK disease activity. TAK is corticosteroid-responsive but relapses upon tapering corticosteroids. Conventional synthetic disease-modifying anti-rheumatic drugs (DMARDs) are the first-line maintenance agents, and tumor necrosis factor-alpha inhibitors, tocilizumab, or tofacitinib are second-line agents for TAK. Revascularization procedures for TAK should be used judiciously during periods of inactive disease.

The effectiveness of tocilizumab and its comparison with tumor necrosis factor alpha inhibitors for Takayasu Arteritis: A systematic review and meta-analysis

Takayasu arteritis (TAK) refractory to conventional disease-modifying anti-rheumatic drugs (DMARDs) is commonly treated with biologic DMARDs such as tocilizumab or tumor necrosis factor-alpha inhibitors (TNFi). The 2021 American College of Rheumatology (ACR) recommendations preferred TNFi to tocilizumab. Therefore, we conducted a systematic review with meta-analysis to assess the evidence base for tocilizumab in TAK by updating a previous systematic review on DMARDs in TAK through searches on MEDLINE, Pubmed Central, Scopus, major international Rheumatology conference abstracts, and clinical trial databases from January 2021 to November 2022. Thirty-five studies involving 1082 TAK [one randomized controlled trial (RCT), eleven controlled and twenty-one uncontrolled studies, most of moderate to high quality] had evaluated tocilizumab in TAK. The RCT of tocilizumab versus placebo failed to meet its primary end-point of superiority of tocilizumab on an intention-to-treat analysis (hazard ratio 0.41, 95%CI 0.15-1.10) but successfully met the secondary end-point of superiority on per-protocol analysis (hazard ratio 0.34, 95%CI 0.11-1.00). A meta-analysis of six studies identified similar rates of clinical remission [risk ratio (RR) tocilizumab vs TNFi 1.03, 95%CI 0.91-1.17)], angiographic stabilization (RR 1.00, 95%CI 0.72-1.40) or adverse events (RR 0.84, 95%CI 0.54-1.31) with tocilizumab or TNFi. A meta-analysis of three studies identified superior clinical response (RR 1.55, 95%CI 1.15-2.10) and adverse effect profile (RR 0.45, 95%CI 0.25-0.80) with tocilizumab than cyclophosphamide. Pooled data from uncontrolled studies identified clinical response in 85%(95%CI 79-91%) and angiographic stabilization in 82% (95%CI 68-94%). Our study suggests similar evidence for treating TAK with tocilizumab or TNFi, contrary to the ACR 2021 recommendations.

Cardiovascular risk in vasculitis

The present review summarizes the burden, risk factors, biomarkers of and therapeutic consideration for cardiovascular disease in systemic vasculitis. Ischemic heart disease (IHD) and stroke are intrinsic features of Kawasaki disease, Takayasu arteritis, Giant Cell Arteritis (GCA), and Behcet's disease. The risk of IHD and stroke is increased in anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) and cryoglobulinemic vasculitis. Behcet's disease could present with venous thromboembolism. The risk of venous thromboembolism is increased in AAV, polyarteritis nodosa, and GCA. The risk of cardiovascular events is greatest at or immediately after the diagnosis of AAV or GCA, therefore, controlling vasculitis disease activity is of utmost importance. Traditional as well as disease-related risk factors drive the heightened cardiovascular risk in vasculitis. Aspirin or statins reduce the risk of IHD or stroke in GCA or the risk of IHD in Kawasaki Disease. Venous thromboembolism in Behcet's disease should be treated with immunosuppressive therapy rather than with anticoagulation.

Cardiovascular risks associated with Janus kinase inhibitors: peering outside the black box

Considerable controversy related to the cardiovascular safety of Janus kinase inhibitors (JAKinibs) has arisen following the results of the ORAL Surveillance trial. In this trial of rheumatoid arthritis (RA) ≥ 50 years with at least one prevalent cardiovascular disease (CVD) risk factor, tofacitinib was not found to be non-inferior to tumour necrosis factor-alpha inhibitors (TNFi) with regards to the risk for major adverse cardiovascular events (MACE), venous thromboembolism (VTE) or malignancy. Following the results of ORAL Surveillance, the United States Food and Drug Administration (US FDA) issued a boxed warning regarding increased risks of MACE, VTE and malignancy with tofacitinib, baricitinib or upadacitinib in inflammatory arthritis or ulcerative colitis. Analysis of data from other trials (including long-term follow-up studies) of tofacitinib in RA, psoriasis, psoriatic arthritis, spondyloarthritis and inflammatory bowel diseases suggests an overall similar risk of MACE or VTE with tofacitinib when compared with TNFi. In specific patient populations with risk factors for or prior history of MACE or VTE, the risk of subsequent MACE or VTE with tofacitinib use is considerably heightened. Post-hoc analyses from ORAL Surveillance presented at the recent EULAR meeting further help to delineate patients with RA at increased risk of MACE/VTE with tofacitinib. Based on the available literature from trials and long-term follow-up studies of baricitinib and upadacitinib, there exists insufficient evidence to extend the warning of MACE/VTE with tofacitinib to these drugs. Ongoing post-marketing surveillance studies of JAKinibs in immune-mediated inflammatory diseases should help clarify CVD risk with JAKinibs.

Comparison of Presentation and Prognosis of Takayasu Arteritis with or without Stroke or Transient Ischemic Attack-A Retrospective Cohort Study

Takayasu arteritis (TAK) could cause a stroke or transient ischemic attack (TIA) in young individuals due to inflammatory vascular occlusion or intracerebral hemorrhage. We compared the clinical presentation, angiographic features, longitudinal patterns of disease activity, medical treatments, and survival in 34 TAK patients with stroke/TIA and 157 without stroke/TIA from a single-center retrospective cohort. TAK patients with stroke/TIA were older (p = 0.044) with a greater proportion of males (p = 0.022), more frequent vision loss (odds ratio (OR) for stroke/TIA vs. without stroke TIA 5.21, 95% CI 1.42-19.14), and less frequent pulse or blood pressure inequality (OR 0.43, 95% CI 0.19-0.96) than TAK patients without stroke/TIA. Hata's angiographic type IIa was more common in TAK patients with stroke/TIA (OR 11.00, 95%CI 2.60-46.58) and type V in TAK patients without stroke/TIA (OR 0.27, 95% CI 0.12-0.58). Cyclophosphamide was used more often in TAK patients with stroke/TIA (p = 0.018). Disease activity at baseline, 6, 12, and 24 months of follow-up was mostly similar for both groups. Risk of mortality was similar in TAK patients with or without stroke/TIA (hazard ratio unadjusted 0.76, 95% CI 0.15-3.99; adjusted for gender, age of disease onset, delay to diagnosis, baseline disease activity, and the number of conventional or biologic/targeted synthetic immunosuppressants used 1.38, 95% CI 0.19-10.20) even after propensity score-matched analyses. Stroke or TIA does not appear to affect survival in TAK patients adversely.

Diagnostik und Therapie der Großgefäßvaskulitiden – Wo stehen wir aktuell?

Die beiden Großgefäßvaskulitiden unterscheiden sich in mehrfacher Hinsicht, vor allem aber durch das Alter der betroffenen Patienten bei Erstmanifestation. Die Riesenzellarteriitis (RZA) ist eine Erkrankung des älteren Patienten wohingegen die Takayasu Arteriitis per definitionem vor dem 40 Lebensjahr auftritt. Die Diagnosen sind in den letzten Jahren durch verbesserte Bildgebung und Therapieoptionen mehr ins Bewusstsein gerückt. Neben der klassischen Steroidtherapie – welche bis heute Mittel der ersten Wahl ist – steht uns mit Tocilizumab, einem monoklonalen Antikörper gegen IL6-Rezeptor, zumindest für die RZA, eine zusätzliche hocheffektive Therapie zur Verfügung. Andere vielversprechende Substanzen befinden sich derzeit in Erprobung. Dieser Artikel soll einen Überblick zu Diagnostik und Therapie, aber auch einen Ausblick zu möglicherweise kommenden medikamentösen Optionen bieten.

Outcome Measures and Biomarkers for Disease Assessment in Takayasu Arteritis

Takayasu arteritis (TAK) is a less common large vessel vasculitis where histopathology of involved arteries is difficult to access except during open surgical procedures. Assessment of disease activity in TAK, therefore, relies on surrogate measures. Clinical disease activity measures such as the National Institutes of Health (NIH) score, the Disease Extent Index in TAK (DEI.TAK) and the Indian TAK Clinical Activity Score (ITAS2010) inconsistently associate with acute phase reactants (APRs). Computerized tomographic angiography (CTA), magnetic resonance angiography (MRA), or color Doppler Ultrasound (CDUS) enables anatomical characterization of stenosis, dilatation, and vessel wall characteristics. Vascular wall uptake of 18-fluorodeoxyglucose or other ligands using positron emission tomography computerized tomography (PET-CT) helps assess metabolic activity, which reflects disease activity well in a subset of TAK with normal APRs. Angiographic scoring systems to quantitate the extent of vascular involvement in TAK have been developed recently. Erythrocyte sedimentation rate and C-reactive protein have a moderate performance in distinguishing active TAK. Numerous novel biomarkers are under evaluation in TAK. Limited literature suggests a better assessment of active disease by combining APRs, PET-CT, and circulating biomarkers. Validated damage indices and patient-reported outcome measures specific to TAK are lacking. Few biomarkers have been evaluated to reflect vascular damage in TAK and constitute important research agenda.

Presentation and clinical course of pediatric-onset versus adult-onset Takayasu arteritis-a systematic review and meta-analysis

Takayasu arteritis (TAK) is a less common large-vessel vasculitis which can occur in either children or adults. However, differences between pediatric-onset and adult-onset TAK have not been systematically analyzed. We undertook a systematic review (pre-registered on PROSPERO, identifier CRD42022300238) to analyze differences in clinical presentation, angiographic involvement, treatments, and outcomes between pediatric-onset and adult-onset TAK. We searched PubMed (MEDLINE and PubMed Central), Scopus, major recent international rheumatology conference abstracts, Cochrane database, and clinicaltrials.gov, and identified seven studies of moderate to high quality comparing pediatric-onset and adult-onset TAK. Meta-analysis of 263 pediatric-onset and 981 adult-onset TAK suggested that constitutional features (fever, and in subgroup analyses, weight loss), hypertension, headache, and sinister features of cardiomyopathy, elevated serum creatinine, and abdominal pain were more frequent in pediatric-onset TAK, whereas pulse loss/pulse deficit and claudication (particularly upper limb claudication) were more frequent in adult-onset TAK. Hata's type IV TAK was more common in pediatric-onset TAK, and Hata's type I TAK in adult-onset TAK. Children with TAK also appeared to require more intense immunosuppression with more frequent use of cyclophosphamide, biologic DMARDs, tumor necrosis factor alpha inhibitors, and, in subgroup analyses, tocilizumab in pediatric-onset TAK than in adult-onset TAK. Surgical or endovascular procedures, remission, and risk of mortality were similar in both children and adults with TAK. No studies had compared patient-reported outcome measures between pediatric-onset and adult-onset TAK. Distinct clinical features and angiographic extent prevail between pediatric-onset and adult-onset TAK. Clinical outcomes in these subgroups require further study in multicentric cohorts.

Perspectives of JAK Inhibitors for Large Vessel Vasculitis

Vasculitis is an inflammation of the blood vessels caused by autoimmunity and/or autoinflammation, and recent advances in research have led to a better understanding of its pathogenesis. Glucocorticoids and cyclophosphamide have long been the standard of care. However, B-cell depletion therapy with rituximab has become available for treating antineutrophil cytoplasmic antibody-associated vasculitis (AAV). More recently, avacopan, an inhibitor of the complement 5a receptor, was shown to have high efficacy in remission induction against AAV. Thus, treatment options for AAV have been expanded. In contrast, in large vessel vasculitis (LVV), including giant cell arteritis and Takayasu arteritis, tocilizumab, an IL-6 receptor antagonist, was shown to be effective in suppressing relapse and has steroid-sparing effects. However, the relapse rate remains high, and other therapeutic options have long been awaited. In the last decade, Janus kinase (JAK) inhibitors have emerged as therapeutic options for rheumatoid arthritis (RA). Their efficacy has been proven in multiple studies; thus, JAK inhibitors are expected to be promising agents for treating other rheumatic diseases, including LVV. This mini-review briefly introduces the mechanism of action of JAK inhibitors and their efficacy in patients with RA. Then, the pathophysiology of LVV is updated, and a rationale for treating LVV with JAK inhibitors is provided with a brief introduction of our preliminary results using a mouse model. Finally, we discuss the newly raised safety concerns regarding JAK inhibitors and future perspectives for treating LVV.

Aging-Related Vascular Inflammation: Giant Cell Arteritis and Neurological Disorders

Aging is characterized by the functional decline of the immune system and constitutes the primary risk factor for infectious diseases, cardiovascular disorders, cancer, and neurodegenerative disorders. Blood vessels are immune-privileged sites and consist of endothelial cells, vascular smooth muscle cells, macrophages, dendritic cells, fibroblasts, and pericytes, among others. Aging also termed senescence inevitably affects blood vessels, making them vulnerable to inflammation. Atherosclerosis causes low-grade inflammation from the endothelial side; whereas giant cell arteritis (GCA) causes intense inflammation from the adventitial side. GCA is the most common autoimmune vasculitis in the elderly characterized by the formation of granulomas composed of T cells and macrophages in medium- and large-sized vessels. Recent studies explored the pathophysiology of GCA at unprecedented resolutions, and shed new light on cellular signaling pathways and metabolic fitness in wall-destructive T cells and macrophages. Moreover, recent reports have revealed that not only can cerebrovascular disorders, such as stroke and ischemic optic neuropathy, be initial or coexistent manifestations of GCA, but the same is true for dementia and neurodegenerative disorders. In this review, we first outline how aging affects vascular homeostasis. Subsequently, we review the updated pathophysiology of GCA and explain the similarities and differences between vascular aging and GCA. Then, we introduce the possible link between T cell aging, neurological aging, and GCA. Finally, we discuss therapeutic strategies targeting both senescence and vascular inflammation.

Novel Th17 Lymphocyte Populations, Th17.1 and PD1+Th17, are Increased in Takayasu Arteritis, and Both Th17 and Th17.1 Sub-Populations Associate with Active Disease

Purpose

We evaluated T helper lymphocyte profile, including novel Th17 subsets Th17.1 (secrete IFN-γ, associate with corticosteroid resistance) and PD1+Th17 (secrete TGF-β1, implicated in fibrosis), and related cytokines in peripheral blood of Takayasu arteritis (TAK).

Materials and Methods

We evaluated circulating Th1, Th2, Th17, Th17.1, PD1+CD4+ T lymphocytes, PD1+Th17, and Treg lymphocytes, inflammatory (IFN-γ, IL-4, IL-6, IL-17A, IL-23, IL-1β, TNF-α) and regulatory (IL-10, TGF-β1) cytokines in peripheral blood of TAK (n = 57; median age 35 (interquartile range 26–45) years; 40 females) in a cross-sectional design. We studied inflammatory and regulatory cytokines in culture supernatant of peripheral blood mononuclear cells (PBMCs) from TAK following stimulation with anti-CD3/anti-CD28 and their modulation by tacrolimus (immunosuppressive) with/without tadalafil (anti-fibrotic). Furthermore, we followed up immunosuppressive-naïve active TAK (n = 16) and compared T helper lymphocyte populations and cytokines before and after immunosuppressive therapy. Healthy controls (HC, n = 21) and sarcoidosis (disease control, n = 11) were compared against TAK.

Results

TAK had higher Th17, Th17.1 and PD1+Th17 lymphocytes than HC (p < 0.001), and higher PD1+CD4+ T lymphocytes than sarcoidosis (p < 0.001). Th17 lymphocytes associated with active TAK after multivariable-adjusted logistic regression (p = 0.008). TAK had greater cytokine secretion from PBMCs (IFN-γ, IL-17A, IL-10 versus HC; IL-6, TNF-α, IL-1β versus HC or sarcoidosis) (p < 0.05). In-vitro, PBMCs from TAK showed reduced secretion of all inflammatory cytokines with tacrolimus, with synergistic reduction in IL-17A, IL-6, IL-1β and IL-10 following addition of tadalafil to tacrolimus. Serial follow-up of immunosuppressive-naïve TAK (n = 16) showed reduction in serum IL-6 and TGF-β1 (p < 0.05) and IL-6 in culture supernatant (p < 0.05) following immunosuppressive therapy.

Conclusion

Novel Th17 sub-populations (Th17.1 and PD1+Th17) are elevated in TAK. Th17 lymphocytes associate with active TAK. In-vitro experiments on cultured PBMCs suggest promise for further evaluation of a combination of immunosuppressive tacrolimus with anti-fibrotic tadalafil (or other anti-fibrotic therapies) in clinical trials of TAK.

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Baricitinib for relapsing giant cell arteritis: a prospective open-label 52-week pilot study

BACKGROUND/PURPOSE

Preclinical vascular inflammation models have demonstrated effective suppression of arterial wall lesional T cells through inhibition of Janus kinase 3 and JAK1. However, JAK inhibition in patients with giant cell arteritis (GCA) has not been prospectively investigated.

METHODS

We performed a prospective, open-label, pilot study of baricitinib (4 mg/day) with a tiered glucocorticoid (GC) entry and accelerated taper in patients with relapsing GCA.

RESULTS

15 patients were enrolled (11, 73% female) with a mean age at entry of 72.4 (SD 7.2) years, median duration of GCA of 9 (IQR 7-21) months and median of 1 (1-2) prior relapse. Four (27%) patients entered the study on prednisone 30 mg/day, 6 (40%) at 20 mg/day and 5 (33%) at 10 mg/day. Fourteen patients completed 52 weeks of baricitinib. At week 52, 14/15 (93%) patients had ≥1 adverse event (AE) with the most frequent events, including infection not requiring antibiotics (n=8), infection requiring antibiotics (n=5), nausea (n=6), leg swelling (n=2), fatigue (n=2) and diarrhoea (n=1). One subject required baricitinib discontinuation due to AE. One serious adverse event was recorded. Only 1 of 14 (7%) patients relapsed during the study. The remaining 13 patients achieved steroid discontinuation and remained in disease remission during the 52-week study duration.

CONCLUSION

In this proof-of-concept study, baricitinib at 4 mg/day was well tolerated and discontinuation of GC was allowed in most patients with relapsing GCA. Larger randomised clinical trials are needed to determine the utility of JAK inhibition in GCA.

TRIAL REGISTRATION NUMBER

NCT03026504.