TED Relapse Patterns After Teprotumumab Differ by Disease Phase

In this study, active phase patients experienced earlier, longer and more severe relapses, while stable phase patients exhibited shorter, nonprogressive symptom return. Photo: Bobby Saenz, OD, MS. Click image to enlarge. Previous studies that have examined relapse rates in thyroid eye disease (TED) patients after treatment with teprotumumab have used different clinical metrics to define relapse. In a recent study, researchers sought to characterize and compare the clinical features, timing and duration of TED relapse after teprotumumab in patients treated during the active versus stable phases of the disease. They found that patients treated in the active phase had relapses that occurred sooner, lasted longer and ultimately resulted in disease that was worse than pre-treatment as compared with those treated in the stable phase.A retrospective case series was conducted of 26 adult patients who experienced a return of TED symptoms after completing teprotumumab therapy between July 2021 and July 2024. Patients were stratified by TED phase at treatment initiation (active vs. stable). Data included clinical history, treatment details and relapse characteristics. Relapse was defined by worsening of proptosis or extraocular motility deficits after completion of treatment. Of 26 patients, 20 were treated during the active phase and six during the stable phase. The study found that TED relapse after teprotumumab differs by disease phase at initiation. Patients treated during the active phase experienced relapse sooner after treatment (8.2 months), lasted longer (11.1 months) and behaved much like previously reported cohorts of active TED patients, including a risk of progression to compressive optic neuropathy. This suggests that teprotumumab acts as a disease modulator.Stable phase patients exhibited shorter, nonprogressive symptom return, which the researchers would term “rebound”—suggesting a distinct mechanism.“Consequently, we feel that “relapses” are funda­mentally different in the active phase and stable phase groups and that this difference should be reflected in appropriate ter­minology,” the authors wrote in their paper. “We propose the term “rebound” for recurrence of signs to baseline levels in stable phase patients, to distinguish it from true “relapse” characterized by progressive reactivation in active phase disease.” This terminology requires validation in larger prospective studies, they added.“The current study demonstrates that, when TED relapses after treatment in the active phase, symptoms will typically con­tinue to progress beyond the severity that provoked the initial treatment and that the post-treatment relapse will last on aver­age nearly one year—an interval similar to untreated TED,” the authors wrote in their paper. “These results further support the concept that, in the active phase, teprotumumab acts as a modulator of TED.”These findings underscore the need for phase-specific counseling, monitoring and further investigation into potentially disparate mechanisms of action of teprotumumab in the acute and stable phases, the authors concluded in their paper.Click here for the journal source. Shabto JM, Shteyman A, Stevens S, et al. Relapse versus rebound in thyroid eye disease after teprotumumab treatment: a retrospective case series. Ophthalmic Plast Reconstr Surg. February 2026. [Epub ahead of print]. This article was developed by the editorial staff in conjunction with experts in the field. In the process, AI may have been among the editorial tools used to meet the goals of human editors, who approved all content.