ETA2023 45th Annual Meeting of the European Thyroid Association ETA 2023 Oral Session 4: Young Investigators / Clinical and Translational (6 abstracts)
1Byers Eye Institute, Stanford University School of Medicine, Department of Ophthalmology, Palo Alto, United States; 2Private Practice, Oculoplastics, Beverly Hills, United States; 3Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Department of Ophthalmology, Miami, United States; 4University of Minnesota, Department of Ophthalmology and Visual Neurosciences, Minneapolis, United States; 5Clayton Eye Center, Morrow, United States; 6Scheie Eye Institute, Perelman School of Medicine, Department of Ophthalmology, Philadelphia, United States; 7Division of Endocrinology, Stanford University School of Medicine, 7. Department of Medicine, Palo Alto, United States; 8Senta Clinic, San Diego, United States; 9Cedars-Sinai Medical Center, Los Angeles, United States
Objectives: The insulin-like growth factor I receptor (IGF-1R) plays a significant role in the pathology of thyroid eye disease (TED), an autoimmune disorder characterized by orbital inflammation. Teprotumumab, a human monoclonal antibody targeting IGF-1R, has demonstrated efficacy in treating moderate-to-severe TED. A significant proportion of patients experienced adverse events (AEs), with 74% and 85% reporting an AE and 12% and 5% reporting serious AEs in Phase 2 and 3 trials, respectively. However, clinical trials had limited inclusion criteria. This study assessed the real-world duration, incidence, and severity of AEs in TED patients treated with teprotumumab.
Methods: This was a multi-center retrospective observational cohort study of patients with TED of all stages and activity levels treated with at least four infusions of teprotumumab. Patients were seen at six tertiary centers in the United States. AE metrics, relation to teprotumumab infusions, and related interventions were assessed throughout patient follow-up. Smoking history, thyroid status, previous thyroid and TED treatments, medications, and medical history were collected on chart review.
Results: The study included 131 patients with a mean CAS reduction of 3.1. Proptosis improved by an average of 3.0±2.1 mm in 76% (100/131) of patients and GDS improved by at least one point for 36.3% (33/91) patients. AEs occurred in 81.7% (107/131) of patients. Patients had a median of 4 AEs. Most AEs were mild (74.0%, 97/131), 28.2% (37/131) were moderate, and 8.4% (11/131) were severe. Mean interval AE onset was 7.9 weeks after the first teprotumumab infusion. Resolved AEs had a mean duration of 18.4 weeks. Patients had a mean follow-up of 70.2±38.5 weeks after the first infusion. Forty-six percent (60/131) of patients had at least 1 persistent AE at last follow-up. The most common type of AEs were 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). The incidence of each type of teprotumumab-related AE was higher in all categories than previously reported (Table 1). Ten patients (7.6%) discontinued therapy due to AEs, including hearing loss (n=4), multiple AEs (n=3), inflammatory bowel disease flare (n=2), and hyperglycemia (n=1).
Our Data | Clinical Trial Data: Teprotumumab-Related | |||
Adverse Event | Affected Patients | Percent | Affected Patients | Percent |
Any AE | 107 | 82% | 47 | 56% |
Muscle Spasm | 76 | 58% | 16 | 19% |
Fatigue | 36 | 27% | 3 | 4% |
Diarrhea | 36 | 27% | 7 | 8% |
Alopecia | 35 | 27% | 8 | 10% |
Hearing Change | 40 | 31% | 4 | 5% |
Dysguesia | 11 | 8% | 4 | 5% |
Hyperglcemia | 14 | 11% | 7 | 8% |
Conclusions: AEs were commonly reported with teprotumumab treatment. Most were mild and reversible; however, serious AEs occurred that warranted treatment cessation. Treating physicians should inform patients about AE risk, properly screen patients prior to treatment, monitor patients closely, and have a low threshold for treating AEs should they develop.