OR27-04 The Effect of Teprotumumab on Thyroid and Ophthalmic Function in Patients with Acute and Chronic Thyroid Eye Disease

Abstract T.D. Hoang: None. S.C. De La Torre: None. R.J. Flor: None. M.K. Shakir: None. F.O. Tuamokumo: None. E. Chou: None. Teprotumumab, an IGF-1R inhibitor, is the first FDA-approved drug to treat thyroid eye disease (TED). We conducted a retrospective study on the effect of teprotumumab on patients with acute and chronic TED. Participants were 18-76 years old at time of treatment. Inclusion factors were a diagnosis of autoimmune thyroid disease with active thyroid eye disease (>1 of: lid retraction, soft tissue involvement, ≥3mm proptosis above normal for race/sex, and diplopia). All were treated with at least one dose of teprotumumab. Twenty-six patients were included in the final analysis. The average age was 47.6 years old [17-76 years]. The mean BMI was 29.5 kg/m2 [20.8-44.5]. The duration of TED ranged from 3-480 months [average 52.8 months], with 85% (n=22) having TED >1 year. This cohort was 73% female and 27% male. Ethnic breakdown was 54% black, 27% white, 15% Asian, and 4% Hispanic. Systemic labs were studied before and after teprotumumab treatment. The mean TSH decreased from 3.16 mIU/L to 1.60 mIU/L with teprotumumab treatment (p=0.055). The mean T4 increased from 1.46 ng/dL before to 1.53 ng/dL after therapy (p=0.03). Total T3 levels increased from 102.3 ng/DL to 108.1 ng/dL (p=0.504). Serum levels of thyrotropin stimulating immunoglobin (TSI) decreased from 10.8 IU/L to 2.5 IU/L (p=0.049) and thyrotropin receptor antibody (TRAb) from 13.8 IU/L to 7.2 IU/L (p=0.089) following treatment. As expected, significant increases in HbA1c from 5.7 to 6.2% (p=0.013) and fasting glucose from 95 mg/dL to 111 mg/dL (p=0.007). Ophthalmologic testing also showed significant changes following teprotumumab infusions. There was a statistically significant reduction in proptosis (p<0.005), Clinical Activity Scale (p<0.005), and retinal nerve fiber layer (RNFL) thickness (p<0.005 right eyes (OD), p=0.048 left eyes (OS)). Statistically significant reduction was noted in the intraocular pressure (IOP) OS (p=0.022) with trending decrease OD (p=0.071). No significant changes were seen in lid retraction (p=0.139 OD and p=0.502 OS), visual field mean deviation (p=0.426 OD, p=0.359 OS), or pattern standard deviation (p=0.881 OD, p=0.643 OS). Most patients tolerated the medication well. The most common side effects were muscle cramps (42%), hyperglycemia (19%), muffled hearing (11.5%), tinnitus (11.5%), and non-bloody diarrhea (11.5%). Fatigue, paresthesia, headache, nausea, hair loss, and dizziness were also reported. This study shows that teprotumumab treatment significantly reduced TSI, proptosis, CAS, RNFL thickness, and IOP in patients with both acute and chronic disease. This shows that the effect of teprotumumab on commonly measured parameters extends past the acute phase of TED and autoimmune thyroid disease. Sunday, June 2, 2024