Tocilizumab in Giant Cell Arteritis: A Real-Life Retrospective Study

Relapse Risk and Safety of Long-Term Tocilizumab Use Among Patients With Giant Cell Arteritis: A Single-Enterprise Cohort Study

OBJECTIVE

To evaluate the safety and efficacy of tocilizumab (TCZ) in giant cell arteritis (GCA) in a large North American cohort.

METHODS

Patients with GCA treated with TCZ between January 1, 2010, and May 15, 2020, were retrospectively identified. Kaplan-Meier methods were used to estimate time to TCZ discontinuation and time to first relapse after TCZ discontinuation. Poisson regression models were used to compare annualized relapse rates before, during, and after TCZ use. Age- and sex-adjusted risk factors associated with relapse on and off TCZ and development of adverse events of significant interest (AESIs) were examined using Cox models.

RESULTS

One hundred fourteen patients (60.5% female) were included with mean (SD) age 70.4 (8.2) years. Median duration from GCA diagnosis to TCZ start was 4.5 months. Median overall duration of TCZ treatment was 2.3 years. Relapse rate prior to TCZ start (0.84 relapses/person-year) was 3-fold reduced while on TCZ (0.28 relapses/person-year; P < 0.001) but increased to 0.64 relapses/person-year after TCZ discontinuation. Fifty-two patients stopped TCZ after a median of 16.8 months; 27 relapsed after discontinuation (median: 8.4 months; 58% relapsed within 12 months). Only 14.9% of patients stopped TCZ because of AESIs. Neither dose/route of TCZ, presence of large-vessel vasculitis, nor duration of TCZ therapy prior to discontinuation predicted relapse after TCZ stop.

CONCLUSION

TCZ is well tolerated in GCA, with low rates of discontinuation for AESIs. However, relapse occurred in > 50% despite median treatment > 12 months. Since the duration of TCZ prior to discontinuation did not significantly affect subsequent risk of GCA recurrence, further research is needed to determine the optimal duration of therapy.

Indirect Comparison of Glucocorticoid-Sparing Agents for Remission Maintenance in Giant Cell Arteritis: A Network Meta-analysis

OBJECTIVE

To compare and rank the effect of glucocorticoid-sparing agents in giant cell arteritis (GCA), for which several drugs have been evaluated but with a benefit-risk balance that remains uncertain.

METHODS

The MEDLINE and Clinical Trials databases were searched up to November 2021; all randomized controlled trials investigating glucocorticoids in GCA were included. The glucocorticoid regimen was dichotomized into short (≤6 months) or prolonged (>6 months) use. Risk of relapse and safety were estimated using network meta-analysis with frequentist random effects models.

RESULTS

Of the 96 records screened, 8 trials were included (572 patients). The trials compared glucocorticoids and a sparing agent: tocilizumab (2 trials), oral methotrexate (3 trials), infliximab (1 trial), etanercept (1 trial), and adalimumab (1 trial). The pooled prevalence of GCA relapse was 52.6% (95% CI, 38.1 to 66.9). The risk of relapse was significantly lower with tocilizumab compared with methotrexate (relative risk [RR], 0.41; 95% CI, 0.17 to 0.97) and prolonged (RR, 0.41; 95% CI, 0.20 to 0.83) and short (RR, 0.32; 95% CI, 0.16 to 0.66) glucocorticoid use. The risk of relapse was not significantly different with methotrexate compared with short (RR, 0.79; 95% CI, 0.48 to 1.31) and prolonged (RR, 0.95; 95% CI, 0.31 to 2.89) glucocorticoid use. The frequency of serious adverse events and serious infection was comparable between the different drugs. The certainty of the evidence was low to very low.

CONCLUSION

This meta-analysis suggests that tocilizumab may be superior to other sparing agents to prevent GCA relapse, but with a low to very low certainty of evidence, and that safety is comparable to the other drugs.

REGISTRATION

The protocol of the meta-analysis is registered in the international prospective register of systematic reviews PROSPERO (https://www.crd.york.ac.uk/prospero/; registration CRD42020112387).

PET-Based Imaging with 18F-FDG and 18F-NaF to Assess Inflammation and Microcalcification in Atherosclerosis and Other Vascular and Thrombotic Disorders

Positron emission tomography (PET) imaging with ¹⁸F-fluorodeoxyglucose (FDG) represents a method of detecting and characterizing arterial wall inflammation, with potential applications in the early assessment of vascular disorders such as atherosclerosis. By portraying early-stage molecular changes, FDG-PET findings have previously been shown to correlate with atherosclerosis progression. In addition, recent studies have suggested that microcalcification revealed by ¹⁸F-sodium fluoride (NaF) may be more sensitive at detecting atherogenic changes compared to FDG-PET. In this review, we summarize the roles of FDG and NaF in the assessment of atherosclerosis and discuss the role of global assessment in quantification of the vascular disease burden. Furthermore, we will review the emerging applications of FDG-PET in various vascular disorders, including pulmonary embolism, as well as inflammatory and infectious vascular diseases.

Diagnostic value of [18F]FDG-PET/CT for treatment monitoring in large vessel vasculitis: a systematic review and meta-analysis

PURPOSE

Monitoring disease activity in patients with large vessel vasculitis (LVV) can be challenging. [18F]FDG-PET/CT is increasingly used to evaluate treatment response in LVV. In this systematic review and meta-analysis, we aimed to summarize the current evidence on the value of [18F]FDG-PET/CT for treatment monitoring in LVV.

METHODS

PubMed/MEDLINE and the Cochrane library database were searched from inception through October 21, 2020. Studies containing patients with LVV (i.e. giant cell arteritis, Takayasu arteritis and isolated aortitis) that received treatment and underwent [18F]FDG-PET/CT were included. Screening, full-text review and data extraction were performed by 2 investigators. The risk of bias was examined with the QUADAS-2 tool. Meta-analysis of proportions and diagnostic test accuracy was performed by a random-effects model and bivariate model, respectively.

RESULTS

Twenty-one studies were included in the systematic review, of which 8 studies were eligible for meta-analysis. Arterial [18F]FDG uptake decreased upon clinical remission in longitudinal studies. High heterogeneity (I² statistic 94%) precluded meta-analysis of the proportion of patients in which the scan normalized during clinical remission. Meta-analysis of cross-sectional studies indicated that [18F]FDG-PET/CT may detect relapsing/refractory disease with a sensitivity of 77% (95%CI 57-90%) and specificity of 71% (95%CI 47-87%). Substantial heterogeneity was observed among the cross-sectional studies. Both variation in clinical aspects and imaging procedures contributed to the heterogeneity.

CONCLUSION

Treatment of LVV leads to reduction of arterial [18F]FDG uptake during clinical remission. [18F]FDG-PET/CT has moderate diagnostic accuracy for detecting active LVV. [18F]FDG-PET/CT may aid treatment monitoring in LVV, but its findings should be interpreted in the context of the clinical suspicion of disease activity. This study underlines the relevance of published procedural recommendations for the use of [18F]FDG-PET/CT in LVV.

Usual and Rare Abdominal Location of Giant Cell Arteritis Diagnosed and Follow-up With 18F-FDG PET/CT

ABSTRACT

Giant cell arteritis is not an uncommon disease, and its extension is furthermore finely assessed with new-generation PET/CT system. 18F-FDG PET/CT is increasingly used in case of large-vessel vasculitis for optimal diagnosis, activity monitoring (even when treated with interleukin 6 receptor inhibitor), and evaluation damage progression. We reported the case of a 61-year-old woman with common giant cell arteritis pattern on 18F-FDG PET/CT (aorta and large arteries) and uptakes in all aorta branches, mainly impressive and uncommon in the abdomen. After 2 years of therapeutic optimization including IV tocilizumab and monitoring with 18F-FDG PET/CT, a complete metabolical response was assessed.

Use of 18F-fluorodeoxyglucose positron emission tomography to monitor tocilizumab effect on vascular inflammation in giant cell arteritis

OBJECTIVES

To evaluate the time-dependent effects of tocilizumab on vascular inflammation as measured by 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) in GCA.

METHODS

Patients with GCA treated with tocilizumab were selected from a prospective, observational cohort. Patients underwent FDG-PET at the baseline visit prior to initiation of tocilizumab and at subsequent follow-up visits performed at 6-month intervals. All imaging findings were interpreted blinded to clinical data. The PET vascular activity score (PETVAS) was used to quantify arterial FDG uptake. Wilcoxon signed rank test was used to compare change in PETVAS between visits. Linear regression was used to determine change in PETVAS over multiple timepoints.

RESULTS

Twenty-five patients with GCA were included. All patients had physician-determined active vasculitis at the baseline visit by clinical assessment and FDG-PET interpretation. PETVAS was significantly reduced in association with tocilizumab treatment from the baseline to the most recent follow-up visit [24.0 (IQR 22.3-27.0) vs 18.5 (IQR 15.3-23.8); P <0.01]. A significant reduction in PETVAS was observed over a two-year treatment period (P <0.01 for linear trend), with a similar degree of improvement in both the first and second years of treatment. Repeat FDG-PET scans after tocilizumab discontinuation showed worsening PET activity in five out of six patients, with two patients subsequently experiencing clinical relapse.

CONCLUSION

Treatment of patients with GCA with tocilizumab was associated with both clinical improvement and reduction of vascular inflammation as measured by serial FDG-PET. Future clinical trials in GCA should study direct treatment effect on vascular inflammation as an outcome measure.

Large vessel vasculitis: imaging standards of 18F-FDG PET/CT

Improvements in positron emission tomography (PET) technology have contributed to increased diagnostic accuracy in patients with large-vessel vasculitis (LVV) over the last decades. Many systematic reviews and meta-analyses were conducted, and earlier diagnosis by ¹⁸F-FDG PET can be made in patients suspected of having LVV. Two subtypes, Takayasu arteritis and giant cell arteritis, will progress when poorly responding to corticosteroids and augmented immunosuppression. In most patients, disease activity cannot be monitored by laboratory tests alone; therefore, glucose metabolism may be a source for possible biomarkers. In this review, we present current concepts regarding ¹⁸F-FDG PET/CT imaging standards.

Real-world evidence in rheumatic diseases: relevance and lessons learnt

An emerging trend in the medical literature, including the Rheumatology literature, is that of accumulating large, multicentric, multi-national data based on registries of patients seen in real life situations. Such real-world evidence (RWE) may help provide valuable insights into the long-term outcomes of disease in unselected patients seen in daily practice, including patients belonging to vulnerable populations such as extremes of age, during pregnancy and lactation. Evidences gathered from real life practice settings can help understand drug prescription patterns, including adherence to treatment guidelines, cost-effectiveness of therapy, and real-life long-term outcomes, and adverse effects of treatment with particular medications. Registry-based data also helps analyze comorbidities in patients with rheumatic diseases, and their impact on quality of life, morbidity and mortality. Traditionally, a randomized controlled trial (RCT), or systematic reviews of multiple, homogenous RCTs, have been considered the cornerstone of evidence-based medicine, and RWE does, at times, provide differing viewpoints from the results of particular drugs in clinical trial settings. Therefore, in the present day, it is prudent to consider the complementary nature of information derived from RWE to that obtained from rigorous, clinical trial settings. Future guidelines for disease management may consider it relevant to include information from RWE in addition to that available from clinical trials, to help devise management guidelines that are harmonious with routine practice settings.

The Treatment of Giant Cell Arteritis in Different Clinical Settings

This paper aims to raise awareness of the different disease courses, comorbidities, and therapy situations in patients with giant cell arteritis (GCA), which require a differentiated approach and often a deviation from current treatment guidelines. With the approval of tocilizumab (TOC), which specifically binds to both soluble and membrane-bound IL-6 receptor and inhibits IL-6 receptor-mediated signaling, the spectrum of available effective treatment options has been significantly broadened. TOC yields an extensive range of possible applications that go beyond a glucocorticoid-saving effect. In this context, the treatment of GCA is dependent on the disease course as well as the associated comorbidities. The different stages of GCA in association to co-morbidities require a detailed treatment strategy.

Giant cell arteritis: early diagnosis is key

Giant cell arteritis (GCA) is an inflammatory vasculitis typically affecting elderly that can potentially cause vision loss. Studies have demonstrated that early recognition and initiation of treatment can improve visual prognosis in patients with GCA. This review addresses the benefits of early diagnosis and treatment, and discusses the available treatment options to manage the disease.