Horizon Therapeutics plc released new findings from its phase 4 clinical trial assessing Tepezza (teprotumumab-trbw) for the treatment of patients with chronic/low clinical activity score (CAS) thyroid eye disease (TED).
Give me a quick refresher on Tepezza.
FDA-approved in 2020 as the first and only treatment indicated for TED, Tepezza is administered via an intravenous injection of 10 mg/kg into the arm followed by 20 mg/kg injection every 3 weeks for 7 additional infusions.
What else?
The FDA approved an update to Tepezza’s indication in April 2023 that specified its use for the treatment of all TED patients, regardless of the disease activity or duration.
And this phase 4 trial?
The randomized, double-masked, placebo-controlled, parallel-group, multicenter trial (NCT04583735) enrolled 62 patients with chronic (inactive) TED and low CAS.
Patients were administered eight infusions of either Tepezza (n = 42) or a placebo (n = 20) for 24 weeks.
Investigators sought to measure the effectiveness of Tepezza versus a placebo in the change of proptosis measurements in the study eye from baseline to Week 24.
What were the original findings?
Released in April 2023, the study’s 24-week topline data met all endpoints and supported previous clinical findings that Tepezza significantly reduced proptosis in TED patients—regardless of disease activity or duration.
See here for the complete findings.
Now talk about this new data.
The latest results found that Tepezza improved visual functioning (measured via Graves’ Ophthalmology Quality of Life Questionnaire [GO-QOL]).
Give me some numbers.
At Week 24 in the pre-specified analysis within the study’s intent-to-treat population, 62% of Tepezza-treated patients achieved a significantly greater average improvement from baseline for visual functioning (8.73) vs 25% of placebo (2.41) (p = 0.03).
Additionally, 63% of patients treated with Tepezza had a meaningful improvement in proptosis (≥2 mm) compared with placebo (7%) (p=0.0008) at Week 24.
Anything that wasn’t statistically significant?
Yup; the appearance subscale endpoint, actually.
At Week 24, Tepezza-treated patients exhibited a 10.03 mm improvement in appearance vs 7.19 mm for placebo (p = 0.65).
How about adverse effects?
According to the company, the number of patients with adverse events was comparable between the two groups, with no safety signals noted.
Expert input.
According to Beth Scott, OD, MS, Horizon vice president, medical affairs: ““These trial data support the potential role of TEPEZZA across a broad range of Thyroid Eye Disease patients, no matter how long they have been living with the disease or how much disease activity they have.”