Is there potential for the approval of monoclonal antibodies to treat thyroid-associated ophthalmopathy?

Cytokines in Thyroid-Associated Ophthalmopathy

Thyroid-associated ophthalmopathy (TAO), also known as thyroid eye disease (TED) or Graves' orbitopathy (GO), is a complex autoimmune condition causing visual impairment, disfigurement, and harm to patients' physical and mental health. The pathogenesis of TAO has not been fully elucidated, and the mainstream view is that coantigens shared by the thyroid and orbit trigger remodeling of extraocular muscles and orbital connective tissues through an inflammatory response. In recent years, cytokines and the immune responses they mediate have been crucial in disease progression, and currently, common evidence has shown that drugs targeting cytokines, such as tocilizumab, infliximab, and adalimumab, may be novel targets for therapy. In this review, we summarize the research development of different cytokines in TAO pathogenesis in the hope of discovering new therapeutic targets.

Autoantibodies - enemies, and/or potential allies?

Autoantibodies are well known as potentially highly harmful antibodies which attack the host via binding to self-antigens, thus causing severe associated diseases and symptoms (e.g. autoimmune diseases). However, detection of autoantibodies to a range of disease-associated antigens has enabled their successful usage as important tools in disease diagnosis, prognosis and treatment. There are several advantages of using such autoantibodies. These include the capacity to measure their presence very early in disease development, their stability, which is often much better than their related antigen, and the capacity to use an array of such autoantibodies for enhanced diagnostics and to better predict prognosis. They may also possess capacity for utilization in therapy, in vivo. In this review both the positive and negative aspects of autoantibodies are critically assessed, including their role in autoimmune diseases, cancers and the global pandemic caused by COVID-19. Important issues related to their detection are also highlighted.

Thyroid Eye Disease: Navigating the New Treatment Landscape

Thyroid eye disease (TED) is a complex inflammatory disease that can have a long clinical course with sight-threatening and debilitating ocular sequelae. Until recently, there were limited therapeutic options available. In the last decade we have gained a deeper understanding of the underlying pathophysiology, which has led to the development of novel effective targeted therapies. This article discusses the challenges encountered in the clinical evaluation and treatment of TED patients, with the goal to empower endocrinologists and ophthalmologists to work together to provide effective multidisciplinary care. We will review recommendations of past clinical guidelines around evaluation and management of TED patients, discuss the randomized controlled trials of new biologic therapies, and explore how to navigate the emerging therapeutic landscape.

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.

A New Era in the Treatment of Thyroid Eye Disease

PURPOSE

Improved understanding of thyroid eye disease (TED) pathogenesis has facilitated identification of a targeted molecular approach for TED treatment offering the potential to halt or slow disease progression in a nonsurgical manner. Herein, we provide a summary of the current knowledge of TED management, followed by discussion of a novel insulin-like growth factor-1 receptor (IGF-1R) antagonist antibody and its potential to change the course of the disease.

DESIGN

Perspective.

METHODS

Review of the literature and authors' experience.

RESULTS

Many publications demonstrate IGF-1R overexpression in TED, and its activation as an autoantigen as a critical factor in TED pathogenesis. Several in vitro studies demonstrate that IGF-1R inhibition attenuates downstream molecular events including cytokine and hyaluronan production, and cellular differentiation. These observations led to the hypothesis that blocking IGF-1R may abrogate the clinical progression of TED. The recent completion of phase 2 and 3 randomized, placebo-controlled trials demonstrate the efficacy and safety of teprotumumab, a fully human monoclonal IGF-1R antagonist antibody, in patients with moderate-to-severe, active TED. Both the phase 2 and the recent phase 3 study results demonstrate that more patients with active TED receiving teprotumumab experienced a meaningful improvement in proptosis.

CONCLUSIONS

Current TED treatment strategies target inflammation and symptoms, but do not modify the disease course. Therefore, proptosis as well as strabismus and its resulting diplopia often remain, impacting patient well-being and quality of life over the long term. Targeted molecular therapy using teprotumumab demonstrates disease-modifying benefits with the potential to shift the paradigm for TED treatment.

Below the Surface: IGF-1R Therapeutic Targeting and Its Endocytic Journey

Ligand-activated plasma membrane receptors follow pathways of endocytosis through the endosomal sorting apparatus. Receptors cluster in clathrin-coated pits that bud inwards and enter the cell as clathrin-coated vesicles. These vesicles travel through the acidic endosome whereby receptors and ligands are sorted to be either recycled or degraded. The traditional paradigm postulated that the endocytosis role lay in signal termination through the removal of the receptor from the cell surface. It is now becoming clear that the internalization process governs more than receptor signal cessation and instead reigns over the entire spatial and temporal wiring of receptor signaling. Governing the localization, the post-translational modifications, and the scaffolding of receptors and downstream signal components established the endosomal platform as the master regulator of receptor function. Confinement of components within or between distinct organelles means that the endosome instructs the cell on how to interpret and translate the signal emanating from any given receptor complex into biological effects. This review explores this emerging paradigm with respect to the cancer-relevant insulin-like growth factor type 1 receptor (IGF-1R) and discusses how this perspective could inform future targeting strategies.