Expert Consensus on the Use of Teprotumumab for the Management of Thyroid Eye Disease Using a Modified-Delphi Approach

Mechanisms in Thyroid Eye Disease: The TSH Receptor Interacts Directly With the IGF-1 Receptor

The pathogenesis of thyroid eye disease (TED) has been suggested as due to signal enhancement in orbital fibroblasts as a result of autoantibody-induced, synergistic interaction between the TSH receptor (TSHR) and the IGF-1 receptor (IGF-1R). This interaction has been explained by a "receptor cross-talk," mediated via β-arrestin binding. Here we have examined if this interaction can be mediated via direct receptor contact using modeling and experimental approaches. First, we docked a model of the leucine-rich domain of the TSHR ectodomain (ECD) to an available cryo-electron microscopy-based structure of the active-state IGF-1R dimer and demonstrated the stability of the complex using molecular dynamics simulations. We then extended the complex with the full-length TSHR and the transmembrane helices of the IGF1R and a 3000 ns simulation also showed stability of this complex. We then performed coimmunoprecipitation studies with anti-TSHR and anti-IGF-1R antibodies using cells expressing the IGF-1R and the full-length TSHR and also cells that expressed the IGF-1R and only the TSHR-ECD and, therefore, unable to bind β-arrestin. These studies showed a 360 kD complex protein in the immunoprecipitation, which was present in both the full-length TSHR and the TSHR-ECD-only expressing cells, evidencing a direct interaction of receptors via their ectodomains in the absence of arrestin. Colocalized staining of TSHR and IGF-1R in the TSHR-ECD cells further supported this direct interaction. These data showed that the TSHR and IGF-1R can interact directly and in the absence of β-arrestin binding. Understanding these interactions is important in the pathogenesis of TED and its therapeutic intervention.

Otolaryngologist surgical preferences for orbital decompression in thyroid eye disease: A North American survey

Background

Orbital decompression is recommended for TED especially in the treatment of severe, refractory cases yet there are no clear guidelines regarding the optimal surgical approach. Previously conducted surveys assessed variations in the management of TED but only amongst ophthalmologists. Our study attempts to better characterize surgical and perioperative preferences amongst otolaryngologists in the management of TED.

Methods

A survey was administered to the American Rhinologic Society and Canadian Society of Otolaryngology - Head and Neck Surgery via REDCap with 52 total respondents. Respondent demographic information and pre-operative management, procedural specifics, and post-operative management preferences were collected.

Results

The majority of respondents practiced in a metropolitan (82.7%), academic setting (73.1%) and received subspecialty training in Rhinology & Skull Base Surgery (88.9%). Most elected for corticosteroids (63.5%) and medical management (69.2%) prior to orbital decompression but did not use any classification system (86.5%). Orbital decompression was most often done with ophthalmology collaboration (71.2%). Removal of two bony walls (55.8%) via medial wall (97.9%) and orbital floor (72.3%) removal was most preferred. Removal of one orbital fat aspect (60.6%) via the medial fat pad was most preferred. Combined bone and fat removal (59.6%) completed via an endoscopic approach (71.2% and 97.0%, respectively) was most common. Post-operatively, most patients were not admitted (88.4%) with saline nasal rinses (92.3%) utilized by most respondents.

Conclusions

This survey completed by otolaryngologists highlights several key distinctions in the preferred surgical approach during orbital decompression and the perioperative management of TED when compared to ophthalmologists and current recommendations.

Level of evidence

Level 4.

A Comprehensive Review of Thyroid Eye Disease Pathogenesis: From Immune Dysregulations to Novel Diagnostic and Therapeutic Approaches

Thyroid eye disease is a complex inflammatory disorder of the orbit that has gained tremendous interest over the past years, and numerous scientific efforts have been deployed to elucidate its pathophysiology for novel drug development. Our manuscript will delve into the molecular dysregulations involved in the pathogenesis of thyroid eye disease that led to its clinical manifestations. Abnormalities within the apoptotic pathway, inflammatory cascade, and autoimmune regulatory systems will be covered. We will further discuss the challenges involved in its diagnosis and management and provide a summary of the current diagnostic tools (i.e., molecular biomarkers, diagnostic scores) from the perspective of clinicians. Finally, our comprehensive literature review will provide a thorough summary of most recent preclinical and clinical studies around the topic of thyroid eye disease, with an emphasis on the manuscripts published within the last five years. We believe our manuscript will bring novelty within the field by bridging the fundamental sciences with the clinical aspect of this disease. This review will be a great tool for clinicians in better understanding the pathogenesis of thyroid eye disease while providing an outlook on future perspectives (i.e., liquid biopsies, artificial intelligence).

Teprotumumab for the Treatment of Thyroid Eye Disease: Why Should We Keep Our Eyes "Wide Open"?-A Clinical and Pharmacovigilance Point of View

Objectives: Thyroid eye disease (TED) treatment has been recently revolutionized with the approval of teprotumumab, a targeted insulin growth factor 1 receptor (IGF1R) inhibitor. To date, teprotumumab is the only FDA-approved drug for treating TED. In this article, we would like to temper the current enthusiasm around IGF1R inhibitors. Methods: critical review of the literature by independent academic practitioners. Results: several questions should be raised. First, "how an orphan drug has become a blockbuster with annual sales exceeding $1 billion?" Teprotumumab infusions are expensive, costing about USD 45,000 for one infusion and USD 360,000 for eight infusions in a 75 kg patient. Teprotumumab approval was based on two randomized clinical trials investigating active (clinical activity score ≥ 4) TED patients. Despite this, teprotumumab was approved by the FDA for "the treatment of TED" without distinguishing between active and inactive forms. The second question is as follows: "how can a new drug, compared only to a placebo, become the new standard without being compared to historically established gold standard medical or surgical treatments?" Teprotumumab has never been compared to other medical treatments in active TED nor to surgery in chronic TED. Up to 75% of patients may experience proptosis regression after treatment discontinuation. Finally, ototoxicity has emerged as a potentially devastating side effect requiring frequent monitoring. Investigation into the long-term side effects, especially in women of childbearing age, is also warranted. Conclusions: Teprotumumab is undoubtedly a major treatment option in TED. However, before prescribing a drug, practitioners should assess its benefit/risk ratio based on the following: (i) evidence-based medicine; (ii) their empirical experience; (iii) the cost/benefit analysis; (iv) the long-term outcomes and safety profile.

Fibrocyte Participation in Thyroid-Associated Ophthalmopathy Suggests New Approaches to Therapy

PURPOSE

Review the historical context of research and changing therapeutic landscape of thyroid-associated ophthalmopathy (TAO) by focusing on the relationship between TAO, CD34+ fibrocytes, thyrotropin receptor (TSHR), and insulin-like growth factor-I receptor (IGF-IR).

METHODS

A literature review using search terms, including fibrocytes, IGF-IR, TSHR, TAO, and thyroid eye disease.

RESULTS

The mechanisms involved in TAO have been partially identified. Substantial progress has been made over several decades, including 1) recognizing the interplay between the professional immune system and orbital tissues; 2) TSHR and IGF-IR act interdependently in mediating the pathogenesis of TAO; 3) Multiple cytokines and specific immune cells are involved in activating and remodeling orbital tissue; 4) Recognition of these mechanisms is allowing the development of target therapies such as teprotumumab, a monoclonal antibody IGF-IR inhibitor approved by the US Food and drug administration for treatment of TAO; and 5) It appears that teprotumumab acts on the systemic immune system peripheral to the orbit.

CONCLUSION

Additional molecules targeting IGF-IR and other plausible disease mechanisms are currently under development. This activity in the TAO therapeutic space portends even greater improvements in patient care.

Dysthyroid Optic Neuropathy

PURPOSE

Dysthyroid optic neuropathy (DON) is a sight-threatening complication of thyroid eye disease (TED). This review provides an overview of the epidemiology, pathogenesis, diagnosis, and current therapeutic options for DON.

METHODS

A literature review.

RESULTS

DON occurs in about 5% to 8% of TED patients. Compression of the optic nerve at the apex is the most widely accepted pathogenic mechanism. Excessive stretching of the nerve might play a role in a minority of cases. Increasing age, male gender, smoking, and diabetes mellitus have been identified as risk factors. Diagnosis of DON is based on a combination of ≥2 clinical findings, including decreased visual acuity, decreased color vision, relative afferent pupillary defect, visual field defects, or optic disc edema. Orbital imaging supports the diagnosis by confirming apical crowding or optic nerve stretching. DON should be promptly treated with high-dose intravenous glucocorticoids. Decompression surgery should be performed, but the response is incomplete. Radiotherapy might play a role in the prevention of DON development and may delay or avoid the need for surgery. The advent of new biologic-targeted agents provides an exciting new array of therapeutic options, though more research is needed to clarify the role of these medications in the management of DON.

CONCLUSIONS

Even with appropriate management, DON can result in irreversible loss of visual function. Prompt diagnosis and management are pivotal and require a multidisciplinary approach. Methylprednisolone infusions still represent first-line therapy, and surgical decompression is performed in cases of treatment failure. Biologics may play a role in the future.

Efficacy of teprotumumab therapy in patients with long-duration thyroid eye disease

PURPOSE OF REVIEW

Teprotumumab, an inhibitor of the insulin-like growth factor 1 receptor (IGF-1R), was approved by the US Food and Drug Administration in January 2020 for the treatment of thyroid eye disease (TED). The clinical trials leading to its approval enrolled patients with recent disease onset and significant inflammatory symptoms and signs. Subsequent real-world teprotumumab use in patients with longer duration of disease also may be effective, and there have been several publications reporting on experience in these patient groups.

RECENT FINDINGS

TED results in disfiguring changes such as ocular proptosis and affects visual function by altering extraocular muscle function, leading to diplopia. Compressive optic neuropathy also may occur, and disease manifestations may persist for years. Teprotumumab treatment in cases of TED in which prior interventions (medical or surgical) had failed, or in treatment-naïve patients whose disease had been stable for years, has been reported to improve both clinical signs and symptoms (proptosis, diplopia) and to reduce the pathologic orbital changes as assessed by orbital imaging.

SUMMARY

Teprotumumab may be an appropriate treatment for TED regardless of disease duration and irrespective of the presence or absence of markers of active inflammation within the orbit.

The Efficacy and Safety of Teprotumumab in Thyroid Eye Disease: Evidence from Randomized Controlled Trials

In this study, we conducted a meta-analysis to assess the efficacy and safety of teprotumumab in treating thyroid eye disease. We searched the Cochrane Library, PubMed, and Embase databases from inception to May 25, 2022, and included all randomized controlled trials. Odds ratios (ORs) were calculated using fixed- or random-effect models. A total of three studies involving 341 patients were identified. Overall, the analysis revealed that teprotumumab demonstrated superior integrated proptosis response compared to placebo in both the intention-to-treat (ITT) population (OR = 17.81, 95% CI = [10.32, 30.76], I2 = 50%) and per-protocol population (OR = 24.53, 95% CI = [12.96, 46.45], I2 = 14%). Furthermore, patients receiving teprotumumab showed significant improvement in overall response (OR = 8.35, 95% CI = [4.74, 14.71], I2 = 79%), diplopia response (OR = 5.53, 95% CI = [3.24, 9.44], I2 = 0%), and achieving a clinical activity score (CAS) of 0 or 1 (OR = 6.26, 95% CI = [3.87, 10.12], I2 = 0%). Moreover, patients treated with teprotumumab experienced greater improvements in proptosis (MD = -2.49, 95% CI = [-2.54, -2.45], I2 = 98%) and Graves' ophthalmopathy-specific quality of life (GO-QOL, MD = 11.48, 95% CI = [11.03, 11.93], I2 = 95%). However, it is important to note that patients receiving teprotumumab had a higher risk of adverse events, including serious adverse events, gastrointestinal adverse reactions, and muscle spasms. In summary, teprotumumab demonstrated greater improvement in proptosis response, proptosis, diplopia response, overall response, GO-QOL, and CAS. Nonetheless, it should be considered that its use is associated with a higher risk of adverse events.

Literature Commentary

In this issue of JNO, Drs. Mark L. Moster, Marc J. Dinkin, and Deborah I. Friedman discuss the following 6 articles:Piehl F, Eriksson-Dufva A, Budzianowska A, Feresiadou A, Hansson W, Hietala MA, Håkansson I, Johansson R, Jons D, Kmezic I, Lindberg C, Lindh J, Lundin F, Nygren I, Punga AR, Press R, Samuelsson K, Sundström P, Wickberg O, Brauner S, Frisell T. Efficacy and safety of rituximab for new-onset generalized myasthenia gravis: the RINOMAX randomized clinical trial. JAMA Neurol. 2022;79:1105-1112.Cortese R, Carrasco FP, Tur C, Bianchi A, Brownlee W, De Angelis F, De La Paz I, Grussu F, Haider L, Jacob A, Kanber B, Magnollay L, Nicholas RS, Trip A, Yiannakas M, Toosy AT, Hacohen Y, Barkhof F, Ciccarelli O. Differentiating multiple sclerosis from AQP4-neuromyelitis optica spectrum disorder and MOG-antibody disease with imaging. Neurology. 2022. doi: 10.1212/WNL.0000000000201465.Carelli V, Newman NJ, Yu-Wai-Man P, Biousse V, Moster ML, Subramanian PS, Vignal-Clermont C, Wang AG, Donahue SP, Leroy BP, Sergott RC, Klopstock T, Sadun AA, Rebolleda Fernández G, Chwalisz BK, Banik R, Girmens JF, La Morgia C, DeBusk AA, Jurkute N, Priglinger C, Karanjia R, Josse C, Salzmann J, Montestruc F, Roux M, Taiel M, Sahel JA; the LHON Study Group. Indirect comparison of Lenadogene Nolparvovec gene therapy versus natural history in patients with leber hereditary optic neuropathy carrying the m.11778G>A MT-ND4 mutation. Ophthalmol Ther. 2022. doi: 10.1007/s40123-022-00611-x.Noll C, Hiltensperger M, Aly L, Wicklein R, Afzali AM, Mardin C, Gasperi C, Berthele A, Hemmer B, Korn T, Knier B. Association of the retinal vasculature, intrathecal immunity, and disability in multiple sclerosis. Front Immunol. 2022;13:997043.Mitchell JL, Buckham R, Lyons H, Walker JK, Yiangou A, Sassani M, Thaller M, Grech O, Alimajstorovic Z, Julher M, Tsermoulas G, Brock K, Mollan SP, Sinclair AJ. Evaluation of diurnal and postural intracranial pressure employing telemetric monitoring in idiopathic intracranial hypertension. Fluids Barriers CNS. 2022;19:85.Pan Y, Chen YX, Zhang J, Lin ML, Liu GM, Xu XL, Fan XQ, Zhong Y, Li Q, Ai SM, Xu W, Tan J, Zhou HF, Xu DD, Zhang HY, Xu B, Wang S, Ma JJ, Zhang S, Gan LY, Cui JT, Li L, Xie YY, Guo X, Pan-Doh N, Zhu ZT, Lu Y, Shi YX, Xia YW, Li ZY, Liang D. Doxycycline vs placebo at 12 weeks in patients with mild thyroid-associated ophthalmopathy: a randomized clinical trial. JAMA Ophthalmol. 2022;140:1076-1083.