Research Highlights Efficacy of Teprotumumab for Thyroid Eye Disease

New data to be presented at the American Academy of Ophthalmology’s annual meeting, AAO 2020, highlight the efficacy of Tepezza (teprotumumab-trbw), the first and only FDA approved medicine for thyroid eye disease (TED).

TED is a rare condition where the muscles and fatty tissues behind the eye become inflamed, causing the eyes to be pushed forward and bulge outward (proptosis). The disease often occurs in individuals living with hypertension or Graves’ disease and in some cases can lead to blindness.

Teprotumumab-trbw, a biologic, was approved in January 2020 after 2 studies found the treatment resulted in a greater frequency of proptosis reduction compared with placebo in patients with TED. The treatment is a targeted inhibitor of the insulin-like growth factor-1 receptor and is administered to patients once every 3 weeks for a total of 8 infusions.

“The most common adverse reactions (incidence ≥5% and greater than placebo) are muscle spasm, nausea, alopecia, diarrhea, fatigue, hyperglycemia, hearing impairment, dysgeusia, headache and dry skin,” according to a statement.​

In one abstract,¹ researchers assessed long-term proptosis response and diplopia grade in patients who received teprotumumab. Data were gleaned from the OPTIC clinical trial.​

After the 24-week study, participants were followed for 48 weeks, with their last infusion taking place at week 21. The researchers found:

• At week 24, 34/41 patients (83%) had a ≥2 mm proptosis reduction and 19/28 (68%) had a ≥1 grade diplopia improvement (16/28 with score of 0) in the teprotumumab arm
• Of these 24-week responders, 19/34 (56%) maintained proptosis response, 11/19 (58%) maintained ≥1 grade diplopia improvement, and 8/16 (50%) maintained a diplopia score of 0 at Week 72

“The majority of teprotumumab-treated patients maintained improvements 51 weeks after the last dose,” the researchers concluded. OPTIC-X, an open-label clinical extension study, will continue to evaluate treatment response.

An additional abstract² explored teprotumumab’s effect on less severe TED (fellow eye). Researchers analyzed data from two 24-week randomized trials in patients with recent-onset (<9 months) TED, where participants received the treatment or placebo every 3 weeks. Specifically, the investigators analyzed proptosis response (≥2 mm reduction), proptosis, and clinical activity score (CAS) reductions.

Eighty-seven placebo and 84 treatment patients were included in the analysis, with mean (SD) baseline proptosis of 21.97 (3.24) and 21.61 (3.51) mm and CAS 4.7 (1.3) and 4.3 (1.7), respectively.

Analyses showed:

• At week 24, more teprotumumab versus placebo patients were fellow-eye proptosis responders (63.1% vs 8.0%; P < .001)
• Mean (SE) fellow-eye proptosis change was −2.39 (0.16) mm with teprotumumab vs +0.15 (0.16) mm with placebo (P < .001)
• Mean (SE) CAS change was −3.42 (0.17) with teprotumumab vs −2.00 (0.16) with placebo (P < .001)

Overall, “The findings support the bilateral effect of teprotumumab and its efficacy in less severe TED,” the authors wrote.

Approximately 4% of patients treated with teprotumumab have reported infusion reactions, which include symptoms like transient increases in blood pressure, feeling hot, tachycardia, dyspnea, headache and muscular pain.

References

1. Douglas RS, Holt RJ, Vescio T, Smith TA, Kahaly GJ. Long-term assessment of proptosis and diplopia from the OPTIC trial of teprotumumab in thyroid eye disease. Presented at: AAO 2020 Virtual; November 13-15, 2020. Abstract PA038.
2. Douglas RS, Wang Y, Holt RJ, Kahlay GJ. Improvement in the fellow eye of patients with TED: pooled analyses from the teprotumumab studies. Presented at AAO 2020 Virtual: November 13-15, 2020. Abstract PO305.