Treatment of thyroid-associated orbitopathy with rituximab--a novel therapy for an old disease: case report and literature review

Monoclonal Antibodies for the Treatment of Graves Orbitopathy: Precision Medicine?

PURPOSE

To summarize the development, nomenclature, and rationale of the reported use of monoclonal antibodies (Mabs) in Graves Orbitopathy (GO) and to undertake a systematic review of the management of GO with Mabs.

METHODS

The Pubmed and Embase databases and the Federal Brazilian searching site (Periódicos-CAPES) were screened. The authors searched all the keywords "monoclonal antibodies," "adalimumab," "belimumab," "infliximab," "rituximab," "teprotumumab," and "tocilizumab" combined with the terms "Graves Orbitopathy," "Graves eye disease" and "thyroid eye disease." All the articles published in English, French, and Spanish from 2000 to May 2022 were screened. Only publications with quantitative data on the activity of orbitopathy, proptosis, or both were included.

RESULTS

Seventy-six articles of the 954 screened records met the inclusion criteria. Seven Mabs were described for treating GO. The three most reported Mabs were Rituximab, Tocilizumab, and Teprotumumab. Only eight randomized clinical trials compared the effect of these three Mabs and Belimumab with the effect of steroids or placebos. Adalimumab, Infliximab, and K1-70 only appeared in a few case series and case reports. Frequent mild-to-moderate and few major side effects occurred with the three most used Mabs. Relapse rates ranged from 7.4% for Tocilizumab to at least 29.4% for Teprotumumab. No randomized clinical trials compared Mabs head-to-head.

CONCLUSION

Considering the lack of head-to-head comparisons between Mabs, the relapse rate, the possibility of severe collateral effects, and the cost of Mabs, it is not clear which Mab is the safest and most useful to treat GO.

The Role of Interleukin-17A and NLRP3 Inflammasome in the Pathogenesis of Graves' Ophthalmopathy

The development of Graves' ophthalmopathy (GO) is associated with autoimmune dysfunction. Recent studies have indicated that IL-17A, inflammasomes, and related cytokines may be involved in the etiology of GO. We sought to investigate the pathogenic role of IL-17A and NLRP3 inflammasomes in GO. Orbital fat specimens were collected from 30 patients with GO and 30 non-GO controls. Immunohistochemical staining and orbital fibroblast cultures were conducted for both groups. IL-17A was added to the cell cultures, and cytokine expression, signaling pathways, and inflammasome mechanisms were investigated using reverse transcription polymerase chain reaction, enzyme-linked immunosorbent assay, Western blotting, and small interfering RNA (siRNA) methods. Immunohistochemical staining showed higher NLRP3 expression in GO orbital tissue than in non-GO controls. IL-17A upregulated pro-IL-1β mRNA levels and IL-1β protein levels in the GO group. Furthermore, IL-17A was confirmed to enhance caspase-1 and NLRP3 protein expression in orbital fibroblasts, suggesting NLRP3 inflammasome activation. Inhibiting caspase-1 activity could also decrease IL-1β secretion. In siRNA-transfected orbital fibroblasts, significantly decreased NLRP3 expression was observed, and IL-17A-mediated pro-IL-1β mRNA release was also downregulated. Our observations illustrate that IL-17A promotes IL-1β production from orbital fibroblasts via the NLRP3 inflammasome in GO, and cytokines subsequently released may induce more inflammation and autoimmunity.

Thyroid eye disease: Redefining its management-A review

Thyroid eye disease (TED) is a debilitating, vision threatening disease that dramatically alters patients' quality of life. Until recently, the management of TED is a long arduous course with supportive therapy, followed by an extensive surgical treatment plan to reverse the disease endpoints. Teprotumumab offers an early, safe therapeutic intervention to help reverse disease end points such as diplopia and proptosis and improve quality of life.

Efficacy of rituximab in patients with Graves' orbitopathy: a retrospective multicenter nationwide study

PURPOSE

The clinical utility of rituximab (RTX) in Graves' orbitopathy (GO) treatment remains controversial since the discrepant results from 2 prospective randomized studies (Stan M et al. J Clin Endocrinol Metab 2015; Salvi M et al. J Clin Endocrinol Metab 2015). The aim of this study was to assess in real life the characteristics and the clinical outcomes of patients with GO treated with RTX in cases of corticosteroid resistance or corticosteroid dependence.

METHODS

Multicenter French retrospective study including patients with moderate-to-severe GO requiring second-line treatment with RTX. Patients were classified according to three main baseline characteristics: clinical inflammation (CAS ≥ 3), oculomotor limitation, and visual dysfunction. Patients were considered as responders if, at 24 weeks (week 24), at least 1 of these 3 parameters improved with no worsening elsewhere.

RESULTS

Forty patients were included (65% smokers, 38% dysthyroidism). Thirty-two patients were treated with RTX alone (one patient excluded owing to side effects): 64.5% had favorable responses at week 24 and significant reduction in baseline CAS (3.29 ± 1.6) at 12 weeks (1.93 ± 1.1; P < 0.001) and at week 24 (1.59 ± 1.1; P < 0.001); reduction in anti-TSH receptor antibodies at week 24 (P < 0.01); and significant improvement of visual acuity (P = 0.04) and ocular hypertonia (P = 0.04) at week 12, but no improvement in oculomotor dysfunction. Eight patients needed emergency treatment with concomitant RTX and orbital decompression, with favorable outcome for 5 patients. Predictive factors for a poor response to RTX were low baseline CAS, smoker, and baseline ocular hypertonia. All patients reported good tolerance except one serious side effect (a cytokine release syndrome).

CONCLUSIONS

The efficiency results of RTX in reducing CAS in this cohort are just between those of Stan and Salvi. This could be explained by our delay before treatment initiation, quicker than Stan but longer than Salvi. RTX appears to be effective as a second-line treatment for the inflammatory component of GO, especially if the disease is highly active and recent.

Preliminary study of abnormalities in saccade dynamics in patients with hyperthyroidism with no pre-existing eye damage

The present study investigated the relationship between hyperthyroidism and thyroid-associated ophthalmopathy by examining saccade dynamics to identify defects in eye tracking in patients with hyperthyroidism with no pre-existing eye damage and sensitive indicators that discriminated eye tracking ability in hyperthyroidism. A total of 33 outpatients with hyperthyroidism and 26 healthy controls participated in visually guided saccade (VGS) analysis. Patients with hyperthyroidism were divided into groups based on their medication status (medicated vs. unmedicated). Main sequence analysis was performed to identify differences in peak velocity and duration, and a general linear model (GLM) was used to identify differences in latency, peak acceleration and peak deceleration among the groups. The present study compared differences in the Spearman's correlation coefficient of the duration of saccades and the acceleration asymmetric index (R_AD) among the groups. V_max values (V_max was the asymptotic value of the PV of saccades of large amplitude) were significantly different between the healthy control and unmedicated-hyperthyroidism groups. The results of the GLM-based analysis indicated no significant differences in saccade latency among the three groups. Peak acceleration was significantly different between the healthy control and unmedicated-hyperthyroidism groups (P<0.01). Peak deceleration was significantly different between the healthy control, unmedicated- and medicated-hyperthyroidism groups (P<0.01). R_AD was significantly different between the healthy control and medicated-hyperthyroidism groups (P=0.004). The results of the present study suggested that patients with hyperthyroidism with no pre-existing eye damage exhibited significantly altered saccade dynamics during VGS. Therefore, R_AD may be used as an indicator to monitor the level of eye movement coordination.

Islet Autoantibodies

Islet autoantibodies are the main markers of pancreatic autoimmunity in type 1 diabetes (T1D). Islet autoantibodies recognize insulin (IAA), glutamic acid decarboxylase (GADA), protein phosphatase-like IA-2 (IA-2A), and ZnT8 (ZnT8A), all antigens that are found on secretory granules within pancreatic beta cells. Islet antibodies, measured by sensitive and specific liquid phase assays, are the key parameters of the autoimmune response monitored for diagnostics or prognostics in patients with T1D or for disease prediction in at-risk individuals before T1D onset. Islet autoantibodies have been the main tool used to explore the natural history of T1D; this review summarizes the current knowledge about the autoantigens and the phenotype of islets autoantibodies acquired in large prospective studies from birth in children at risk of developing T1D.

Advances in the pharmacological treatment of Graves' orbitopathy

Graves' orbitopathy has a deteriorating effect on patients' appearance and vision, thus significantly decreases their quality of life. A multidisciplinary team of endocrinologists, ophthalmologists, head and neck surgeons, nuclear medicine physicians, radiologists, and psychologists should constitute a standard health care team for those patients. It is vital that the therapy is based on an individual approach, with patients being well informed and involved in the decision-making process. Generally, traditional therapies include immunosuppression with steroids, orbital irradiation and surgical decompression. Novel treatment modalities include: biological agents, somatostatin analogs, antioxidants, methotrexate. Better insight into pathogenesis of Graves' orbitopathy is the only chance for targeted therapy development.

Rituximab in the Treatment of Thyroid Eye Disease: A Review

Graves disease is an autoimmune thyroid disease classically characterised by a clinical triad consisting of hyperthyroidism, diffuse goitre, and thyroid eye disease. Thyroid eye disease is an immunologically mediated condition in which humoral immunity is thought to play a central role. Thyroid eye disease is traditionally treated with high-dose glucocorticosteroids and surgical orbital decompression. However, responses are inadequate and alternative treatment options are needed. Rituximab, an anti-CD20 monoclonal antibody, shows promise as a novel therapeutic option for thyroid eye disease. There are 43 cases of thyroid eye disease treated with rituximab in the medical literature, and larger studies are warranted to determine the long-term effectiveness of rituximab. Rituximab may represent an attractive new treatment option for thyroid eye disease, especially in the case of disease that is refractory to current treatment strategies.

Randomized controlled trial of rituximab in patients with Graves' orbitopathy

CONTEXT

Graves' orbitopathy (GO) is a potentially sight-threatening disease for which available medical therapy is not uniformly successful. Multiple case series suggest that rituximab (RTX) may be effective therapy for GO patients.

OBJECTIVE

To determine the efficacy of RTX in GO.

DESIGN

It is a prospective, randomized, double-masked, placebo-controlled trial.

SETTING

The study was conducted at a large academic private practice.

PATIENTS

Twenty five patients with active moderate to severe GO were enrolled, and 21 completed the study to the primary endpoint.

INTERVENTIONS

Two RTX infusions (1000 mg each) or two saline infusions were given 2 weeks apart.

MAIN OUTCOME MEASURES

The primary endpoint was a reduction in clinical activity score (CAS) assessed as a continuum and separately as improvement by ≥ 2 points at 24 weeks. Secondary endpoints included success and failure rates, proportions showing clinically significant improvement in proptosis, lid fissure width, diplopia score, lagophthalmos and disease severity, and changes in those parameters, orbital fat/ muscle volume and quality-of-life.

RESULTS

The treatment groups were similar in all parameters at baseline. The last observation was carried forward if the patient discontinued prematurely. No differences were found in the proportions of patients showing CAS improvement at 24 weeks (25% placebo; 31% RTX, P = .75) or in CAS decrease from baseline to 24 or 52 weeks [mean 1.5 points (1.8 SD) placebo; 1.2 (2 SD) RTX at 24 weeks, P = .73]. Similarly, there were no differences between groups in any of the secondary endpoints at either 24 or 52 weeks. There were four adverse events (AE) in 3/12 placebo patients and 11 AE in 8/13 RTX-treated patients; 5/6 moderate or severe AE occurred in the RTX group.

CONCLUSION

RTX offered no additional benefit over placebo to our patients with active and moderate to severe GO and carried with it non-negligible adverse effects.

Intraorbital injection of rituximab versus high dose of systemic glucocorticoids in the treatment of thyroid-associated orbitopathy

The aim of the study was to compare, in a randomized prospective study, the efficacy and safety of intraorbital administration of low doses of RTX versus intravenous glucocorticoids (GCs) to treat patients affected by moderately severe thyroid-associated active orbitopathy. Twenty patients with active, moderately severe TAO, whose mean age was 56.7 years±10.2 SD participated in the study. Patients were randomly selected and treated with intraorbital injections of RTX or with i.v. GCs. Disease activity and severity were assessed by the Clinical Activity Score (CAS) and the NOSPECS. Computed tomography or magnetic resonance scans were performed in all patients. In the RTX group, full blood cell count and flow cytometric analysis on peripheral blood lymphocytes were done. The patients were followed for 20 months. In both groups, CAS and NOSPECS indexes were significantly reduced (p<0.005). In particular, CAS reduction was evident since the first follow-up with both treatments. Proptosis decreased significantly only in group B and diplopia showed no significant changes during follow-up times in both groups. Neither of the treatments affected the peripheral TRab. In group A, 5 weeks after the first injection, the CD20+ peripheral lymphocytes value was nearly zero. One patient treated with rituximab progressed to severe TAO (optic neuropathy) following the second injection so the treatment was discontinued. The data confirm the therapeutic efficacy of RTX in active TAO, even in low doses and locally administered. The efficacy on the inflammatory component of the disease is comparable to that of steroids and seems to be related with the reduction of peripheral CD20+ lymphocytes. Caution should be given to an accurate patient selection.