Horizon Therapeutics Public Limited Company 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 92nd Annual Meeting of the American Thyroid Association (ATA 2023), September 27- October 1, 2023 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.

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. Horizon also announced further results from the TEPEZZA Phase 4 clinical trial in TED patients with long disease duration and low CAS.

Findings reinforced a meaningful reduction of proptosis at Week 24 for all subgroups (=2mm) with comparable improvements regardless of magnitude of baseline proptosis levels (<=25 vs >25mm). Smokers treated with TEPEZZA had a change from baseline (CFB) of -2.83 mm (vs 0.00 CFB for placebo); treated non-smokers had a -2.39 mm CFB (vs -1.00 mm for placebo). Males treated with TEPEZZA (n=10) had a CFB of -2.20 mm (vs -1.00 for placebo, n=2), and in treated females (n=29), CFB was -2.55 mm (vs -0.89 for placebo, n=18).

Additionally, research on the impact of TED on patients? QOL was presented at ATA 2023, assessing how characteristics like sex, age and severity of symptoms affect visual functioning and appearance as measured by the Graves? Ophthalmopathy Quality of Life (GO-QOL) questionnaire.

The analysis looked at baseline GO-QOL data for 171 moderate-to-severe TED patients prior to treatment in two clinical trials. Visual functioning results showed that the majority of participants reported limitations in important daily activities like reading (74%) or driving (64%), and nearly all (95%) were affected by the changes in their appearance. Certain sub-populations noted more significant impact on their daily activities, including those with severe diplopia (n=74) and patients with more proptosis (n=104).

Warnings and Precautions: Infusion Reactions: TEPEZZA may cause infusion reactions. Infusion reactions have been reported in approximately 4% of patients treated with TEPEZZA. Reported infusion reactions have usually been mild or moderate in severity.

Signs and symptoms may include transient increases in blood pressure, feeling hot, tachycardia, dyspnea, headache, and muscular pain. Infusion reactions may occur during an infusion or within 1.5 hours after an infusion. In patients who experience an infusion reaction, consideration should be given to premedicating with an antihistamine, antipyretic, or corticosteroid and/or administering all subsequent infusions at a slower infusion rate.

Preexisting Inflammatory Bowel Disease: TEPEZZA may cause an exacerbation of preexisting inflammatory bowel disease (IBD). Monitor patients with IBD for flare of disease. If IBD exacerbation is suspected, consider discontinuation of TEPEZZA.

yperglycemia: Increased blood glucose or hyperglycemia may occur in patients treated with TEPEZZA. In clinical trials, 10% of patients (two-thirds of whom had preexisting diabetes or impaired glucose tolerance) experienced hyperglycemia. Hearing Impairment Including Hearing Loss: TEPEZZA may cause severe hearing impairment including hearing loss, which in some cases may be permanent.

Assess patients? hearing before, during, and after treatment with TEPEZZA and consider the benefit-risk of treatment with patients. Adverse Reactions: The most common adverse reactions (incidence =5% and greater than placebo) are muscle spasm, nausea, alopecia, diarrhea, fatigue, hyperglycemia, hearing impairment, dysgeusia, headache, dry skin, weight decreased, nail disorders, and menstrual disorders.