Horizon Pharma’s late-stage treatment for active thyroid eye disease continues to demonstrate greater efficacy. Two months after releasing positive Phase III data, the company shared additional secondary endpoint data that shows higher levels of patient benefit.
In February, Horizon Pharma announced positive late-stage results of its investigational asset, teprotumumab. In that data, Horizon said teprotumumab demonstrated a meaningful improvement in proptosis, or bulging of the eye, which is the main cause of morbidity in TED. In that trial, teprotumumab vastly outperformed placebo, with 82.9percent of teprotumumab patients achieving the primary endpoint of a 2 mm or more reduction in proptosis. That was in comparison to 9.5 percent of placebo patients. The data was stronger than Phase II results, which showed 69 percent versus 20 percent favorability. On Friday, Horizon announced the new data for the additional secondary endpoints that teprotumumab hit in that trial.
Horizon said the new data shows a dramatic reduction in proptosis and a substantial improvement in overall response rate in patients treated with teprotumumab compared with placebo. The additional data showed that during a 24-week treatment period, patients using teprotumumab had an average proptosis reduction of 2.82 mm compared to 0.54 mm for those who received placebo. Additionally, Horizon reported stronger response rates for teprotumumab. Patients treated with teprotumumab had an overall responder rate of 78 percent compared with 7.1 percent in the placebo group at week 24, the company said.
The additional data, which was presented at the 2019 American Association of Clinical Endocrinologists (AACE) Scientific and Clinical Congress in Los Angeles, demonstrated the potential for teprotumumab to become a treatment for Active TED, which currently has no U.S. Food and Drug Administration approved treatments. One analyst also believes that the strength of the data demonstrates that, if approved, teprotumumab should become the company’s key commercial asset in the 2020s.
Writing on Seeking Alpha, an analyst under the name ONeil Trader said the Horizon asset has continued to demonstrate exceptional efficacy and safety results from Phase II to Phase III in treatment of a disease that has no current approved medications. When taking the Phase III results posted in February and the additional data released Friday into account, ONeil Trader called the data “outstanding” and said it has “de-risked a major part of the company’s pipeline.” ONeil Trader went on to suggest that teprotumumab is likely to become the company’s most valuable asset in a few years. Based on pricing if the drug is approved by regulatory agencies in the U.S. and globally, ONeil Trader predicted teprotumumab could pull in billions annually.
Shao-Lee Lin, Horizon Pharma’s chief scientific officer and head of R&D, noted that the company will continue to share additional analysis of secondary endpoints from the Phase III trials at various medical conferences. All of the secondary endpoints demonstrated statistical significance, Lin said.
“As Horizon continues its evolution into a research-focused company, we strive to address some of the most challenging and overlooked rare diseases. We’ve met with and learned from the thyroid eye disease community – those living with the disease and the physicians who treat them – and these interactions have given us urgency to bring forward an effective option where none currently exist,” Lin said in a statement.
Active thyroid eye disease is a progressive and debilitating autoimmune disease with a limited window of active disease during which it may respond to medical intervention. As TED progresses, it causes serious damage – including proptosis (eye bulging), strabismus (misalignment of the eyes), and diplopia (double vision) – and in some cases can lead to blindness
Raymond Douglas, the principal investigator of teprotumumab and director of the orbital and thyroid eye disease program at Cedars-Sinai Medical Center, said people who are living with Active TED who received teprotumumab in the study achieved key outcomes that are not addressed by current therapeutic approaches.
“Currently, patients with Active TED suffer through life-altering symptoms and – once the active phase of disease ends – are often left with permanent damage. The results of this confirmatory study, together with the Phase II results, suggest that teprotumumab may help reduce proptosis and alleviate the inflammatory symptoms of Active TED, potentially avoiding the need for multiple complex surgeries,” Douglas said in a statement.