Horizon Therapeutics plc announced results of a new analysis examining rates of hyperglycemia among patients treated with TEPEZZA for TED compared to placebo in the Phase 2 and OPTIC Phase 3 clinical trials. These results were presented as part of the annual conference of the Endocrine Society, ENDO 2022, June 11-14 in Atlanta, Georgia. Data will also be published in a supplemental issue of the Journal of the Endocrine Society.

TEPEZZA is the first and only medicine approved by the U.S. Food and Drug Administration (FDA) specifically for the treatment of TED – a serious, progressive and potentially vision-threatening rare autoimmune disease. Results of the clinical development program demonstrated TEPEZZA markedly improves symptoms of TED, including proptosis and diplopia. Since FDA approval in 2020, Horizon has continued to analyze available data concerning TEPEZZA use in the clinic to understand the overall safety profile, including rates of high blood sugar, or hyperglycemia, while on therapy.

For this analysis, data were pooled from clinical trials to review blood glucose and hemoglobin A1C (HbA1c) measurements in participants, including both those previously diagnosed with carbohydrate intolerance/diabetes mellitus as well as those without histories of either. Patients in clinical trials had blood glucose and HbA1c checked before study entry and were monitored throughout the trial. Patients with diabetes were required to have well-controlled stable disease to enter the study.

The analysis found a total of nine adverse event (AE) reports of hyperglycemia in eight patients (8/84, 10%) who received TEPEZZA, and one patient (1/86; 1.2%) who received placebo. The majority (5/8, 63%) of patients who experienced hyperglycemia while taking TEPEZZA had pre-existing diabetes. Of the hyperglycemic AEs reported in the TEPEZZA-treated patients, all were controlled with medicine.

All reported AEs were grade 1 (>ULN-160mg/dl) or grade 2 (161 – 250mg/dl), and none led to study discontinuation. HbA1c levels increased by 0.22% in those treated with TEPEZZA compared to 0.04% among placebo patients. A separate post-hoc analysis of pooled clinical trial data assessed the efficacy of TEPEZZA in mildly hypothyroid patients, defined as those with low baseline FT4 levels (n=9).

Responses in patients who were mildly hypothyroid were consistent with those in the overall pooled population, including mean proptosis reduction (2.9 mm and 3.14 mm, respectively); diplopia response (86% and 70%, respectively); and clinical activity score (CAS) response (67% and 62%, respectively).