Reactivation after teprotumumab treatment for active thyroid eye disease

PURPOSE:To determine the recurrence and reactivation rates after teprotumumab therapy for active thyroid eye disease. DESIGN:Retrospective consecutive case series. METHODS:Setting: Institutional, Study Population: All patients followed for active thyroid eye disease at the Cole Eye Institute treated with teprotumumab between May 2020 and May 2021. Patients with under 6-months follow-up after completion of infusions were excluded., Outcome Measures: Primary outcome measure was reactivation, defined as a regression in proptosis (increase of ≥2mm in either eye and to within ≤ 2mm of pre-treatment level) and CAS (worsening of 2 points or greater). Secondary outcome was diplopia response. RESULTS:Twenty-one patients were included in the study. The average long-term improvement in proptosis in the eye with more proptosis after teprotumumab was 1.57mm (range, -3-4 mm). Of the 17/21 of initial responders, there were 8 reactivations (47%) and 2 isolated proptosis regressions (12%); Overall, 7/21 patients (33%) responded throughout the study period. Average time to regression was 12.25 months (range, 2-22.5 months). There was no statistically significant change in diplopia at final visit in any subgroup (p=0.68->0.99). CONCLUSIONS:At most, 33% of patients demonstrate continued response two years after teprotumumab treatment. The proptosis and CAS regression occurs in the setting of disease reactivation in 80% of regressions. Teprotumumab treatment appears to offer minimal long term improvement in diplopia.