Response to tocilizumab treatment in Graves' ophthalmopathy by measuring rectus muscle thickness and chemosis using optical coherence tomography

Efficiency and Safety of Tocilizumab for the Treatment of Thyroid Eye Disease: A Systematic Review

PURPOSE

To review existing literature concerning the effectiveness and safety of tocilizumab (TCZ) for managing thyroid eye disease.

METHODS

A systematic search was conducted across the PubMed and Embase databases to identify studies on TCZ therapy, from inception to May 2023. The search included the keywords "Graves orbitopathy," "thyroid ophthalmopathy," "thyroid eye disease," "thyroid-associated orbitopathy," "thyroid-associated ophthalmopathy," "Graves ophthalmopathy," "endocrine ophthalmopathy," and "Tocilizumab." Only articles written in English, Spanish, or French were considered.

RESULTS

Among the 1,013 articles initially screened, a total of 29 fulfilled the eligibility criteria and were selected. Most studies were case reports or case series, and only one randomized clinical trial was found. TCZ has been used mainly in glucocorticoid-resistant or relapsing cases, with a dosage ranging from 4 or 8 mg/kg every 4 weeks when intravenous or a weekly subcutaneous dose of 162 mg. Treatment duration is usually adjusted to the clinical response. TCZ is mostly effective in reducing inflammatory signs during the active phase of thyroid eye disease, with an improvement of at least 3 points in clinical activity score and an overall relapsing rate of 8.2%. Numerous studies have shown marked reductions in proptosis; although the only available randomized controlled trial reported a nonstatistically significant improvement 6 months after treatment, a recent meta-analysis indicated that TCZ seems to be the most effective treatment for reducing proptosis. No severe side effects related to intravenous or subcutaneous TCZ administration were reported.

DISCUSSION

Despite these promising findings, randomized clinical trials to directly compare the efficacy and safety of TCZ and other currently available therapeutic options are needed.

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.

Steroid-Resistant Graves' Orbitopathy Treated with Tocilizumab in Real-World Clinical Practice: A 9-Year Single-Center Experience

This study aimed to assess the effectiveness and safety of tocilizumab use for the treatment of active steroid-resistant Graves’ orbitopathy (GO). A retrospective longitudinal study was conducted by reviewing the medical records at a single center between November 2009 and December 2018. A total of 114 patients with steroid-resistant Graves’ orbitopathy were examined and treated with tocilizumab, of which 54 adults met the inclusion criteria. No concomitant medication for the treatment of orbitopathy was used. The main primary outcomes included changes from baseline in the Clinical Activity Score (CAS) and thyrotropin receptor antibody (TRAb) levels throughout therapy with tocilizumab. The absolute responses to treatment were defined as the achievement of CAS ≤ 1 and TRAb ≤ 10 U/L. A composite ophthalmic score including CAS, proptosis, eyelid retraction, and diplopia was used to evaluate individual improvement in GO. Adverse drug reactions were also assessed. Analysis of the patient’s CAS and TRAb levels showed meaningful reductions during tocilizumab treatment. Differences between values at baseline and subsequent time points were statistically significant (p < 0.001 for all comparisons). The absolute CAS response (CAS = 0 or 1) was achieved in 74% (37/50) of patients after the fourth dose of tocilizumab (at week 16), with a TRAb response being achieved in 55% (23/42) of patients. The relative CAS response (reduction ≥ 2 points) was achieved in 90.9% of patients (40/44) after the first dose of tocilizumab (at week 4). Measurements of proptosis (reduction ≥ 2 mm in 78% of patients, 42/54) and eyelid retraction (reduction ≥ 2 mm in 75%, 33/44), and the prevalence of diplopia (improvement in 68%, 19/28) were significantly reduced after the last dose of tocilizumab (p < 0.001 for all comparisons). GO improved in 98% (53/54) of patients when at least two criteria of the composite evaluation were required. Four patients exhibited disease recurrence, defined as an increase in CAS of ≥2 points in the six months following the date of inactivation. Most adverse drug reactions were mild or moderate in severity. In conclusion, our data suggest that a course of at least 4 months (one monthly dose) of tocilizumab therapy provides a significant benefit to patients with active moderate-to-severe steroid-resistant GO.

Cytokines as Targets of Novel Therapies for Graves' Ophthalmopathy

Graves' disease (GD) is an organ-specific autoimmune disorder of the thyroid, which is characterized by circulating TSH-receptor (TSH-R) stimulating antibodies (TSAb), leading to hyperthyroidism. Graves' ophthalmopathy (GO) is one of GD extra-thyroidal manifestations associated with the presence of TSAb, and insulin-like growth factor-1 receptor (IGF-1R) autoantibodies, that interact with orbital fibroblasts. Cytokines are elevated in autoimmune (i.e., IL-18, IL-6) and non-autoimmune hyperthyroidism (i.e., TNF-α, IL-8, IL-6), and this could be associated with the chronic effects of thyroid hormone increase. A prevalent Th1-immune response (not related to the hyperthyroidism per se, but to the autoimmune process) is reported in the immune-pathogenesis of GD and GO; Th1-chemokines (CXCL9, CXCL10, CXCL11) and the (C-X-C)R3 receptor are crucial in this process. In patients with active GO, corticosteroids, or intravenous immunoglobulins, decrease inflammation and orbital congestion, and are considered first-line therapies. The more deepened understanding of GO pathophysiology has led to different immune-modulant treatments. Cytokines, TSH-R, and IGF-1R (on the surface of B and T lymphocytes, and fibroblasts), and chemokines implicated in the autoimmune process, are possible targets of novel therapies. Drugs that target cytokines (etanercept, tocilizumab, infliximab, adalimumab) have been tested in GO, with encouraging results. The chimeric monoclonal antibody directed against CD20, RTX, reduces B lymphocytes, cytokines and the released autoantibodies. A multicenter, randomized, placebo-controlled, double-masked trial has investigated the human monoclonal blocking antibody directed against IGF-1R, teprotumumab, reporting its effectiveness in GO. In conclusion, large, controlled and randomized studies are needed to evaluate new possible targeted therapies for GO.

Anti-IL-6 Receptor Tocilizumab in Refractory Graves' Orbitopathy: National Multicenter Observational Study of 48 Patients

Graves' orbitopathy (GO) is the most common extrathyroidal manifestation of Graves' disease (GD). Our aim was to assess the efficacy and safety of Tocilizumab (TCZ) in GO refractory to conventional therapy. This was an open-label multicenter study of glucocorticoid-resistant GO treated with TCZ. The main outcomes were the best-corrected visual acuity (BVCA), Clinical Activity Score (CAS) and intraocular pressure (IOP). These outcome variables were assessed at baseline, 1st, 3rd, 6th and 12th month after TCZ therapy onset. The severity of GO was assessed according to the European Group on Graves' Orbitopathy (EUGOGO). We studied 48 (38 women and 10 men) patients (95 eyes); mean age ± standard deviation 51 ± 11.8 years. Before TCZ and besides oral glucocorticoids, they had received IV methylprednisolone (n = 43), or selenium (n = 11). GO disease was moderate (n =29) or severe (n = 19) and dysthyroid optic neuropathy (DON) (n = 7). TCZ was used in monotherapy (n = 45) or combined (n = 3) at a dose of 8 mg/kg IV every four weeks (n = 43) or 162 mg/s.c. every week (n = 5). TCZ yielded a significant improvement in all of the main outcomes at the 1st month that was maintained at one year. Comparing the baseline with data at 1 year all of the variables improved; BCVA (0.78 ± 0.25 vs. 0.9 ± 0.16; p = 0.0001), CAS (4.64 ± 1.5 vs. 1.05 ± 1.27; p = 0.0001) and intraocular pressure (IOP) (19.05 ± 4.1 vs. 16.73 ± 3.4 mmHg; p = 0.007). After a mean follow-up of 16.1 ± 2.1 months, low disease activity (CAS ≤ 3), was achieved in 88 eyes (92.6%) and TCZ was withdrawn in 29 cases due to low disease activity (n = 25) or inefficacy (n = 4). No serious adverse events were observed. In conclusion, TCZ is a useful and safe therapeutic option in refractory GO treatment.

Thyroid eye disease: current and potential medical management

INTRODUCTION

Thyroid eye disease (TED) is the most frequent extra-thyroid manifestation of Graves' disease and it is more frequent in middle age and in female gender. Nowadays, the causal mechanisms of this disease are not completely understood, but the current available studies suggest that the main causative factor is the thyroid stimulating hormone receptor.

MATERIALS AND METHODS

To collect reports on TED medical management, a thorough literature search was performed in PubMed database. An additional search was made in Google Scholar to complete the collected items.

RESULTS

Among the indentified risk factors, tobacco habit is the most relevant. The main criteria to choose a suitable treatment are the activity and severity of the disease. Support measures can be used to improve the patient's symptoms in any phase of the disease. There is a large number of drugs proposed to manage TED, although with different reported rates of success.

CONCLUSIONS

Currently, the drugs of choice are corticosteroids in moderate-to-severe and in sight-threatening forms. The main problem of corticosteroids is their spectrum of side effects. Therefore, other alternatives are being suggested for medical management of this disease. The efficacy of these alternatives remains unclear.

Correlation Between Optical Coherence Tomography and Magnetic Resonance Imaging of Rectus Muscle Thickness Measurements in Graves' Ophthalmopathy

PURPOSE

To assess the correlation between optical coherence tomography (OCT) and magnetic resonance imaging (MRI) measurements of extraocular rectus muscle thickness in patients with Graves' ophthalmopathy.

METHODS

This was a cross-sectional observational study conducted in 62 eyes of 31 patients with Graves' ophthalmopathy. The disease phase was inactive in 20 patients and active in the remaining 11. The OCT measurements obtained were: medial rectus thickness at 7.2 and 9.2 mm from the limbus and lateral rectus thickness at 8.5 mm from the limbus. MRI measurements were maximum transversal diameter (T-MRI), craniocaudal diameter (CC-MRI), and muscle area (A-MRI).

RESULTS

For the whole patient cohort, correlation emerged between the OCT-MR and T-MRI measurements (R = 0.428 to 0.576; P ≤ .002), A-MRI (R = 0.562 to 0.674; P < .001), and CC-MRI (R = 0.286 to 0.293; P ≤ .046). In patients with clinically active Graves' ophthalmopathy, correlations with T-MRI (R = 0.576 to 0.604; P ≤ .010) and A-MRI (R = 0.678 to 0.706; P < .001) were higher. No correlations were detected between OCT and MRI measurements of lateral rectus thickness (P ≥ .177), regardless of disease phase.

CONCLUSIONS

The correlations observed suggest OCT could be a complementary assessment or screening method to detect thickening of the anterior portion of the medial rectus muscle in patients with Graves' ophthalmopathy, which may be especially useful when MRI is not available. [J Pediatr Ophthalmol Strabismus. 2019;56(5):319-326.].