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

Effectiveness of janus kinase inhibitors in relapsing giant cell arteritis in real-world clinical practice and review of the literature

BACKGROUND

A substantial proportion of patients with giant cell arteritis (GCA) relapse despite standard therapy with glucocorticoids, methotrexate and tocilizumab. The Janus kinase/signal transducer and activator of transcription (JAK/STAT) signalling pathway is involved in the pathogenesis of GCA and JAK inhibitors (JAKi) could be a therapeutic alternative. We evaluated the effectiveness of JAKi in relapsing GCA patients in a real-world setting and reviewed available literature.

METHODS

Retrospective analysis of GCA patients treated with JAKi for relapsing disease at thirteen centers in Spain and one center in United States (01/2017-12/2022). Outcomes assessed included clinical remission, complete remission and safety. Clinical remission was defined as the absence of GCA signs and symptoms regardless of the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) values. Complete remission was defined as the absence of GCA signs and symptoms along with normal ESR and CRP values. A systematic literature search for other JAKi-treated GCA cases was conducted.

RESULTS

Thirty-five patients (86% females, mean age 72.3) with relapsing GCA received JAKi therapy (baricitinib, n = 15; tofacitinib, n = 10; upadacitinib, n = 10). Before JAKi therapy, 22 (63%) patients had received conventional synthetic immunosuppressants (e.g., methotrexate), and 30 (86%) biologics (e.g., tocilizumab). After a median (IQR) follow-up of 11 (6-15.5) months, 20 (57%) patients achieved and maintained clinical remission, 16 (46%) patients achieved and maintained complete remission, and 15 (43%) patients discontinued the initial JAKi due to relapse (n = 11 [31%]) or serious adverse events (n = 4 [11%]). A literature search identified another 36 JAKi-treated GCA cases with clinical improvement reported for the majority of them.

CONCLUSIONS

This real-world analysis and literature review suggest that JAKi could be effective in GCA, including in patients failing established glucocorticoid-sparing therapies such as tocilizumab and methotrexate. A phase III randomized controlled trial of upadacitinib is currently ongoing (ClinicalTrials.gov ID NCT03725202).

Review of phase 2/3 trials in polymyalgia rheumatica and giant cell arteritis

INTRODUCTION

GCA (giant cell arteritis) and PMR (polymyalgia rheumatica) are two overlapping inflammatory rheumatic conditions that are seen exclusively in older adults, sharing some common features. GCA is a clinical syndrome characterized by inflammation of the medium and large arteries, with both cranial and extracranial symptoms. PMR is a clinical syndrome characterized by stiffness in the neck, shoulder, and pelvic girdle muscles. Both are associated with constitutional symptoms.

AREAS COVERED

In this review, we assess the established and upcoming treatments for GCA and PMR. We review the current treatment landscape, completed trials, and upcoming trials in these conditions, to identify new and promising therapies.

EXPERT OPINION

Early use of glucocorticoids (GC) remains integral to the immediate management of PMR and GCA but being aware of patient co-morbidities that may influence treatment toxicity is paramount. As such GC sparing agents are required in the treatment of PMR. Currently there are limited treatment options available for PMR and GCA, and significant unmet needs remain. Newer mechanisms of action, and hence therapeutic options being studied include CD4 T cell co-stimulation blockade, IL-17 inhibition, IL-12/23 inhibition, GM-CSF inhibition, IL-1β inhibition, TNF-α antagonist and Jak inhibition, among others, which will be discussed in this review.

Examining the Safety Profile of Janus Kinase (JAK) Inhibitors in the Management of Immune-Mediated Diseases: A Comprehensive Review

Janus kinase (JAK) inhibitors have heralded a paradigm shift in the management of immune-mediated diseases. While their efficacy is well-established, the safety concerns associated with these agents, particularly regarding thromboembolic events (TE), remain a focus of extensive research and clinical scrutiny. This comprehensive literature review embarks on an exploration of the multifaceted landscape of JAK inhibitors, providing insights into their safety profiles across diverse immune-mediated diseases. The introduction highlights the transformative influence of JAK inhibitors in the treatment of immune-mediated diseases. Historically, the therapeutic arsenal for these conditions included corticosteroids, disease-modifying antirheumatic drugs (DMARDs), and biologics. The advent of JAK inhibitors has revolutionized this landscape, although concerns about their safety persist. This review strives to comprehensively evaluate their safety, amalgamating knowledge from multiple studies and trials. The subsequent sections delve into the safety of specific JAK inhibitors in the context of rheumatoid arthritis, inflammatory bowel diseases, and dermatologic conditions and their associations with venous thromboembolism. The evolving understanding of TE risk, particularly the intricate relationship between these agents and immune-mediated diseases, is meticulously unravelled. The concluding remarks underscore the dynamic nature of TE risk assessment with regard to immune-mediated diseases involving JAK inhibitors. It underscores that risk assessment is multifactorial, influenced not only by the choice of JAK inhibitor but also by the nuances of the underlying immune-mediated disease and the unique patient characteristics. This review offers a holistic perspective on TE risks associated with JAK inhibitors and contributes to the ongoing dialogue regarding their safety in the realm of immune-mediated diseases.