Teprotumumab and the Evolving Therapeutic Landscape in Thyroid Eye Disease

Teprotumumab versus intravenous methylprednisolone in thyroid eye disease: A systematic review

Thyroid eye disease (TED), also known as thyroid-associated ophthalmopathy, is an autoimmune disorder caused due to a complex interplay between autoantigens including the thyroid-stimulating hormone receptor and the insulin-like growth factor-I receptor. TED is characterized by progressive proptosis or diplopia. This systematic review aimed to compare the efficacy of the newer monoclonal antibody - teprotumumab and intravenous methylprednisolone (IVMP) in TED patients. We performed a systematic review of previously published studies from 2013 to June 2023. A total of 329 articles were screened; among them, 111 non-duplicate publications were identified. After the screening of titles and abstracts, 156 publications were excluded; then, another 47 published papers were excluded after the full-text screening. The remaining 15 eligible studies were included in this systematic review. The majority of studies used either teprotumumab alone or in combination with others. Among 15 studies, eight studies used teprotumumab in TED patients, whereas remaining 7 studies used a standard treatment regimen. This systematic review provides an overview of the existing treatment options using monoclonal antibody - teprotumumab and IVMP in TED patients. The overall assessment provides a finding that antibody - teprotumumab is is a good choice compared to conventional IVMP for providing better outcomes in patients with TED.

The effect of teprotumumab infusion on ocular alignment in patients with symptomatic thyroid eye disease

BACKGROUND

Thyroid eye disease (TED) can result in proptosis and ocular misalignment, leading to eye pain, diplopia, and vision loss. Teprotumumab, a humanized antibody against insulin-like growth factor 1 receptor, was approved in 2020 for the treatment of TED. The purpose of this study was to describe the effect of a full course of teprotumumab on ocular misalignment.

METHODS

The medical records of patients who underwent treatment with teprotumumab for active moderate-to-severe TED at a single institution from April 2020 to September 2023 were reviewed retroactively. Sensorimotor examination was performed at each visit using simultaneous prism-cover testing. Demographic information and previous history of radioactive iodine, steroids, strabismus surgery, and smoking were extracted from the record for analysis.

RESULTS

A total of 19 patients were treated during the study period, of whom 11 had strabismus and diplopia. The initial absolute horizontal misalignment in these 11 was 6.0Δ ± 1.5Δ, vertical misalignment was 7.7Δ ± 2.4Δ, and total misalignment was 11.5Δ ± 2.0Δ. On completion of treatment, these measurements decreased by 2.0Δ ± 1.5Δ, 2.2Δ ± 1.0Δ, and 3.2Δ ± 1.6Δ, respectively (P = 0.10, 0.02, and 0.04, resp.). Eight patients (73%) had a decrease in their strabismus, and 5 (46%) reported complete resolution of their diplopia at the final visit. No factors were predictive of which patients would have resolution of their misalignment. Of the remaining 3 patients who had no improvement in ocular alignment, 2 (66%) underwent strabismus surgery. Of the 8 patients with improvement of strabismus, only a single patient (13%) underwent strabismus surgery for persistent diplopia.

CONCLUSIONS

In our study cohort, a full course of teprotumumab coincided with complete resolution of diplopia in 46% of patients and a decrease in strabismus in 73% of patients.

Glycemic Trends in Patients with Thyroid Eye Disease Treated with Teprotumumab in 3 Clinical Trials

PURPOSE

Assess incidence, severity, and glucose excursion outcomes in thyroid eye disease (TED) patients receiving the insulin-like growth factor-1 receptor inhibitor teprotumumab from 3 clinical trials.

DESIGN

Analysis of pooled glycemic data over time.

PARTICIPANTS

Eighty-four teprotumumab- and 86 placebo-treated active TED patients from the phase 2 and phase 3 (OPTIC) controlled clinical trials and 51 teprotumumab-treated patients from the OPTIC extension (OPTIC-X) trial.

METHODS

Eight intravenous infusions were given over 21 weeks. Phase 2 serum glucose was measured at weeks 1, 4, 15, and 21, with fasting measurements at weeks 1 and 4. Serum glucose was measured at each study visit in OPTIC and OPTIC-X, with fasting measurements at weeks 1 and 4 (in patients without diabetes) or all visits (in patients with diabetes). In all studies, hemoglobin A1c (HbA1c) was measured at baseline, 12, and 24 weeks plus weeks 36 and 48 in OPTIC-X.

MAIN OUTCOME MEASURES

Serum glucose and HbA1c.

RESULTS

In the phase 2 and 3 studies, 9 hyperglycemic episodes occurred in 8 teprotumumab patients; mean HbA1c level increased 0.22% from baseline to week 24 (to 5.8%; range, 5.0%-7.9%) versus 0.04% in patients receiving the placebo (to 5.6%; range, 4.6%-8.1%). At study end, 78% (59/76) of teprotumumab patients and 87% (67/77) of patients receiving placebo had normoglycemic findings. Normoglycemia was maintained in 84% (57/68) of patients receiving teprotumumab and 93% (64/69) of patients receiving placebo. Among baseline prediabetic patients, 43% (3/7) remained prediabetic in both groups, and 29% (2/7) of teprotumumab patients and 14% (1/7) of patients receiving placebo had diabetic findings at week 24. OPTIC-X patients trended toward increased fasting glucose and HbA1c whether initially treated or retreated with teprotumumab. Fasting glucose commonly rose after 2 or 3 infusions and stabilized thereafter. Most hyperglycemic incidents occurred in patients with baseline prediabetes/diabetes but were controlled with medication. No evidence was found for progression or increased incidence of hyperglycemia with subsequent doses.

CONCLUSIONS

Serious glycemic excursions are uncommon in patients with normoglycemia before teprotumumab therapy. Patients with controlled diabetes or impaired glucose tolerance can be treated safely if baseline screening, regular monitoring of glycemic control, and timely treatment of hyperglycemia are practiced.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

A Review of Novel Medical Treatments for Thyroid Eye Disease

Thyroid eye disease (TED) is the most common extrathyroidal manifestation of Graves disease. There has been no effective medication to prevent proptosis in thyroid eye disease until 2020 when the anti-insulin-like growth factor 1 receptor (anti-IGF-1R) antibody, Teprotumumab, was approved by the US Food and Drug Administration, sparking increased interest in immune-based drug development. This study aims to review the newly developed drug therapy as well as conventional treatment for TED. Treatment of TED has traditionally been high-dose steroids and orbital radiotherapy, but recently there has been a paradigm shift in the treatment of TED in the United States with the introduction of the therapeutic agent teprotumumab, which dramatically reduces proptosis. However, concerns remain about the development of hearing impairment as a potentially fatal complication and long-term safety. Recently, several clinical trials are underway to assess the efficacy and safety of novel drugs targeting mammalian target of rapamycin complex 1, interleukin-6, fragment crystallizable receptor, and IGF-1R in treating TED. With the explosive increase in interest from academia and pharmaceutical companies in TED, there is anticipation for the development of drugs that are equivalent or superior to teprotumumab while being safer.

Successful Case of Teprotumumab Treatment in an Adolescent Patient With Thyroid Eye Disease

A 16-year-old black female presented with a 4-month history of significant proptosis and diplopia in the setting of diagnosed Graves disease. The patient underwent 8 infusions of teprotumumab. She had migraines and diplopia that were resolved with treatment. There was also a dramatic improvement in her proptosis. The authors present the first reported case of successful teprotumumab treatment in an adolescent patient, describing outcomes and proposing a mechanism for her transient side effects.

Efficacy and Safety of Teprotumumab in Patients With Thyroid Eye Disease of Long Duration and Low Disease Activity

CONTEXT

Early inflammatory thyroid eye disease (TED) can lead to symptomatic chronic disease, including disabling proptosis. Teprotumumab, an insulin-like growth factor-1 receptor (IGF-1R) inhibitor, previously demonstrated efficacy in acute, high-inflammation TED trials.

OBJECTIVE

We present data from the first placebo-controlled trial with teprotumumab in chronic/low disease activity TED.

METHODS

This randomized double-masked, placebo-controlled trial, conducted at 11 US centers, enrolled adult participants with TED duration of 2 to 10 years, Clinical Activity Score (CAS) ≤ 1 or no additional inflammation or progression in proptosis/diplopia for ≥1 year, proptosis ≥3 mm from before TED and/or from normal, euthyroid/mildly hypo/hyperthyroid, no prior teprotumumab, and no steroids within 3 weeks of baseline. Patients received (2:1) intravenous teprotumumab or placebo once every 3 weeks (total 8 infusions). The primary endpoint was proptosis (mm) improvement at Week 24. Adverse events (AEs) were assessed.

RESULTS

A total of 62 (42 teprotumumab and 20 placebo) patients were randomized. At Week 24, least squares mean (SE) proptosis improvement was greater with teprotumumab (-2.41 [0.228]) than with placebo (-0.92 [0.323]), difference -1.48 (95% CI -2.28, -0.69; P = .0004). Proportions of patients with AEs were similar between groups. Hyperglycemia was reported in 6 (15%) vs 2 (10%) and hearing impairment in 9 (22%) vs 2 (10%) with teprotumumab and placebo, respectively. AEs led to discontinuation in 1 teprotumumab (left ear conductive hearing loss with congenital anomaly) and 1 placebo patient (infusion-related). There were no deaths.

CONCLUSION

Teprotumumab significantly improved proptosis vs placebo in longstanding/low inflammation TED, demonstrating efficacy regardless of disease duration/activity. The safety profile was comparable to that previously reported.

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.

Refractory Thyroid Eye Disease Unresponsive to Teprotumumab: A Case Report

Thyroid eye disease (TED) is a complex autoimmune condition that can cause proptosis, ophthalmoplegia, diplopia, optic nerve compression, and vision loss. These clinical findings are caused by a complex pathological mechanism characterized by thyroid-stimulating hormone receptor autoantibodies activating thyroid-stimulating hormone receptors (TSH-Rs). Overexpressed insulin-like growth factor 1 (IGF-1) receptors found in orbital fibroblasts form complexes with these TSH-Rs, leading to the inflammation and expansion of these tissues. Teprotumumab, a human monoclonal antibody sold under the brand name Tepezza, is currently the only FDA-approved immunotherapy for the treatment of TED. Given as an intravenous infusion every three weeks, teprotumumab works by suppressing IGF-1 receptors, thereby interfering with TSH-R and IGF-1 complex-mediated actions in these fibroblasts. The efficacy of teprotumumab was established in randomized, placebo-controlled clinical trials, which demonstrated clinically meaningful improvements in proptosis, inflammation, and diplopia. While teprotumumab has been shown to be efficacious, our patient with TSHRAb-positive euthyroid thyroid-associated ophthalmopathy who presented with diplopia did not have any significant improvement following the standard treatment dose of eight infusions over a 24-week period. This case underscores not only barriers to treatment, such as the high cost of teprotumumab but also highlights the importance of identifying risks for nonresponse.

Teprotumumab-trbw as a Novel Monoclonal Antibody for Thyroid Eye Disease: A Literature Review

Thyroid eye disease (TED) can cause disfigurement and vision loss, most commonly in patients with Graves' disease. These symptoms are related to orbital inflammation subsequently cause proptosis and limited eye movement. Traditionally, TED is treated with corticosteroids to decrease inflammation and surgery once the disease stabilizes. However, multiple medications that play a role in immune modulation have been tested and found to be beneficial in treating TED, either as an adjuvant to steroids or in severe disease resistant to steroids. Teprotumumab-trbw, a novel monoclonal antibody sold under the trade name Tepezza®, is the first immune modulator to be approved by the Unites States Food and Drug Administration (FDA) for TED. Teprotumumab-trbw targets the insulin-like growth factor-1 receptor, which is upregulated on orbital fibroblasts and decreases activation in patients with TED. The FDA approved this drug for patients with less than nine months of disease duration and high levels of disease activity. Multiple studies have shown significant positive results in disease modulation, as well as limited side effects.