Teprotumumab-Related Adverse Events in Thyroid Eye Disease: A Multicenter Study

Abstract

PurposeTo assess the duration, incidence, reversibility, and severity of adverse events (AEs) in patients with thyroid eye disease (TED) treated with teprotumumab. DesignMulti-center retrospective observational cohort study. ParticipantsPatients with TED of all stages and activity levels treated with at least 4 infusions of teprotumumab. MethodsPatients were treated with teprotumumab between February 2020 and October 2022 at 6 tertiary centers. AE metrics were solicited and recorded at each visit. AEs were grouped according to the United States FDA Adverse Event Reporting System. Main Outcome MeasuresPrimary outcomes measure: AE incidence and onset. Secondary outcome measures: AE severity, reversibility, duration, proptosis response, clinical activity score (CAS) reduction, and Gorman diplopia score (GDS) improvement. ResultsThe study evaluated 131 patients. Proptosis improved by 2mm or more in 77% (101/131) of patients with 3.0±2.1mm average proptosis improvement and 3.2 points average CAS reduction. GDS improved by at least one point for 50% (36/72) of patients with baseline diplopia. AEs occurred in 81.7% (107/131) of patients. Patients had a median of 4 AEs. Most patients’ AEs were mild (74.0%, 97/131), 28.2% (37/131) moderate, and 8.4% (11/131) severe. Mean interval AE onset was 7.9 weeks after the first infusion. Resolved AEs had a mean duration of 17.6 weeks. Forty-six percent (60/131) of patients had at least 1 persistent AE at last follow-up. Patients had a mean follow-up of 70.2±38.5 weeks after the first infusion. The most common type of AEs was musculoskeletal (58.0%, 76/131), followed by gastrointestinal (38.2%, 50/131), skin (38.2%, 50/131), ear and labyrinth (30.5%, 40/131), nervous system (20.6%, 27/131), metabolic (15.3%, 20/131), and reproductive system (12.2%, 16/131). Sixteen patients (12.2%) discontinued therapy due to AEs, including hearing loss (n=4), inflammatory bowel disease flare (n=2), hyperglycemia (n=1), muscle spasms (n=1), and multiple AEs (n=8). ConclusionsAEs are commonly reported while receiving teprotumumab treatment. Most are mild and reversible; however, serious AEs can occur and may warrant treatment cessation. Treating physicians should inform patients about the AE risk, properly screen patients prior to treatment, monitor patients closely throughout therapy, and understand how to manage AEs should they develop.