New Analysis Highlights Importance of Adhering to Uninterrupted Full Course of Treatment with TEPEZZA (teprotumumab-trbw) to Support Thyroid Eye Disease (TED) Patient Outcomes

Horizon Therapeutics plc (Nasdaq: HZNP) today announced new data showing that disrupting the recommended TEPEZZA treatment regimen by lengthening the amount of time between infusions can increase the need for a second course of treatment. These findings, along with new subgroup data from the TEPEZZA Phase 4 clinical trial in patients with long disease duration and low Clinical Activity Score (CAS) and an analysis of the impact of TED on QOL, were shared at the 92^nd Annual Meeting of the American Thyroid Association (ATA 2023), Sept. 27-Oct. 1 in Washington, D.C. TEPEZZA is the first and only medicine approved by the U.S. Food and Drug Administration (FDA) for the treatment of TED regardless of disease activity or duration. TED is a serious, progressive, debilitating and potentially vision-threatening rare autoimmune disease.¹

The FDA-approved dosing schedule for TEPEZZA is one infusion every three weeks for a total of eight IV infusions. An analysis examined whether patients who experience a treatment disruption, defined as a >60-day gap between consecutive infusions, are more likely to need a second course of treatment. Deidentified data of patients prescribed a second course of TEPEZZA after receiving an initial full course were examined for TED-related claims, enrollment for a second course, number of infusions and time between courses. Undisrupted patients (n=4,230) and disrupted patients (n=1,155) were observed for one year after the initial full course of treatment. The majority of treatment disruptions (96%) were related to the short-term TEPEZZA supply disruption that occurred in late 2020 as a result of government-mandated COVID-19 vaccine production orders. Chi-square tests were performed for significance.

The findings revealed that a higher portion of patients who experienced a disruption in their first course of TEPEZZA were prescribed an additional course of treatment compared with those who completed an undisrupted initial course of TEPEZZA (10.5% vs 6.5%; p<0.0001). There was also a difference in claims of proptosis between the groups, with a 5% increase of proptosis among disrupted patients vs a 19% reduction in the undisrupted group pre- to post- treatment with TEPEZZA.²

“This analysis reinforces the importance of adhering to the FDA-approved dosing schedule for TEPEZZA and not lengthening the time between consecutive infusions unless there is a safety concern,” said Shoaib Ugradar, MD, private practice, Beverly Hills, CA. “Although treatment delays may result from factors that a prescriber may not directly control, such as changes in insurance coverage or scheduling difficulties, and additional research on this is needed, physicians play an important role in making patients aware that delaying infusions could impact results.”