While teprotumumab has efficacy in treating thyroid eye disease (TED), particularly moderate-to-severe disease, adverse events (AEs) related to treatment are common.
Study Design
This was a multicenter retrospective cohort study of 131 consecutive patients with TED treated with teprotumumab between February 2020 and October 2022. Patients were given an initial intravenous infusion of 10 mg/kg and then infusions of 20 mg/kg every 3 weeks (8 infusions in total), and were queried and evaluated for treatment-related AEs during and after treatment.
Outcomes
Eighty-two percent of patients experienced at least 1 AE during the study period, with all patients experiencing a mean of 4 AEs. The onset of AEs was a mean of 7.9 weeks after the first infusion. Most AEs were mild, with 8.4% of patients experiencing a serious event; however, 12% of patients discontinued treatment due to AEs. The most common AEs were headache, fatigue, diarrhea, and alopecia.
Limitations
Because this was a multicenter study, AEs were not detected using a specific protocol, but rather at the discretion of the treating provider, and each center varied in its approach to collecting AE information. This may have led to an underreporting or overreporting of side effects.
Clinical Significance
Currently, teprotumumab is the only approved treatment for TED and is effective for moderate-to-severe disease. Teprotumumab targets insulin-like growth factor, which is involved in multiple physiologic processes, possibly leading to the development of adverse effects. As is true with any new medication, as physicians gain more experience in the use of teprotumumab, its side-effect profile is becoming better defined. Increased surveillance should be performed in patients with a history of hearing loss, diabetes, or inflammatory bowel disease, which can all worsen significantly with treatment with teprotumumab and were the main AEs that caused patients to discontinue treatment in this study. The authors recommend that patients undergo various tests before prescribing teprotumumab, including thyroid function and baseline and repeat hemoglobin A1C and audiometry. If significant AEs occur, providers should consider pausing teprotumumab, and severe side effects may warrant discontinuation of therapy.
Financial Disclosures: Dr. Richard Allen discloses no financial relationships.