Teprotumumab for the treatment of Thyroid eye disease.

ABSTRACT

Thyroid eye disease (TED) is the most common extra thyroidal manifestation of Graves' disease (GD). It may also present in those who are hypothyroid or euthyroid. The characteristic clinical manifestations of TED chemosis, lid swelling, proptosis and diplopia are driven by a combination of inflammation and extracellular matrix modification. It has recently emerged that one of the major drivers of this molecular signature is the over-expression of the insulin like growth factor-1 receptor (IGF-1R) on key effector cells in TED pathogenesis. The overexpression of the IGF-1R is coupled with a dysregulation of the IGF-1R axis, which links other pathways that modulate inflammation, such as fibrosis and extracellular matrix organization, in patients with TED. This overexpression is also found to persist from the acute stage into the chronic phase. Teprotumumab, a fully human immunoglobulin (Ig) G1 monoclonal antibody that inhibits the IGF-1R, recently gained approval in the US for the treatment of TED. In phase 2 and phase 3 clinical studies, teprotumumab showed efficacy in reducing inflammation, proptosis, diplopia and burden on quality of life, in patients who were treated. Post introduction studies have confirmed the results of the phase 2 and phase 3 studies. Since 2020, over 5, 800 patients have been treated with teprotumumab and it appears to be well tolerated. The American Thyroid Association and the European Thyroid Association have recommended it as first line therapy for patients with moderate to severe TED, who display features of proptosis and diplopia.