The Rate of Re-treatment in Patients Treated with Teprotumumab: A Multicenter Study of 119 Patients with 1 Year of Follow-up

Abstract

Objective or PurposeTo determine the rate of retreatment in patients who receive a full course of teprotumumab therapy for Thyroid Eye Disease (TED) and drivers of retreatment. DesignMulti center, retrospective study SubjectsAll patients who received a full course of treatment and had available data at 1 year post initial treatment were included. MethodsCharts were reviewed for the following information: age, gender, months since diagnosis of TED, smoking status, prior treatments. Further, the clinical activity score (CAS), proptosis and the Gorman diplopia score were reviewed at baseline, at the end of the first course and at baseline for the second course in those who received it. A logistic regression model was created to review the drivers of retreatment. Main Outcome MeasuresRate of retreatment and the drivers of retreatment. Results119 patients were included from 3 centers across the US. The overall retreatment rate was 24% (29/119). There was no difference between the 3 sites (p = 0.6). In univariate analyses, at baseline, there was no difference in proptosis (p = 0.07), diplopia score (p = 0.4) or duration of TED (p = 0.4), between retreated and non-retreated patients. From the retreated group, 82% had a significant proptosis response (≥ 2 mms reduction from baseline) following their initial course, while 68% of patients had a clinically significant proptosis response in the non-retreated group (p = 0.16). The use of other treatments prior to the first infusion of teprotumumab and baseline thyroid dysfunction, were not significantly different between the retreated and non-retreated groups (p = 0.06 and 0.09, respectively). The mean (SD) difference between the end of first treatment and at baseline prior to second treatment (in those who received it) was 2 (2) for CAS, 2 mms (4) for proptosis and 1 (1) for diplopia. Age as the only significant driver of retreatment (p < 0.05). Retreated patients were 7 years older than their non retreated counterparts (age 60 vs 53 (p < 0.05). ConclusionsIn patients receiving a full course of teprotumumab therapy, the rate of retreatment is 24%. Age is the only driver of retreatment.