Horizon shares data on eye disease drug as FDA decision nears

Horizon Pharma has presented additional phase 3 data on teprotumumab in patients with active thyroid eye disease (TED).

TED is an autoimmune disease that typically only remains active for three years, but it can leave sufferers with permanent damage, including impaired vision.

In February, Horizon revealed that a confirmatory phase 3 trial of teprotumumab in TED had met its primary and secondary endpoints. The data enabled Horizon to file for FDA approval of the inhibitor of insulin-like growth factor type 1 receptor.

Now Horizon has shared new data that covers three secondary endpoints in the hopes of persuading the FDA to approve teprotumumab.

After 24 weeks, 68% of patients experienced improvements in their double vision, compared to 29% in the placebo group. The result was statistically significant and, according to the lead investigator, important for patients.

“People suffering from double vision often lose the ability to perform daily tasks, like reading and driving, impacting their ability to work and causing depression,” Raymond Douglas, of Cedars Sinai Medical Center, said in a statement. “The results of this study are very encouraging.”

Horizon also tracked a statistically significant improvement on a quality of life scale. The average change in the teprotumumab arm was 13.79 points, compared to 4.43 points in the control cohort. Earlier external research found patients consider improvements of six to ten points to be important.

The third and final new endpoint discussed by Horizon tracked performance on a seven-point scale of TED disease activity. In the teprotumumab arm, 59% of patients were at one of the two lowest points on the disease activity scale at week 24, compared to 21% in the control group.

Publication of the results comes eight months after Horizon revealed 82.9% of patients who received teprotumumab experienced a 2mm or more reduction of proptosis, compared to 9.5% in the control group. That was the primary endpoint of the study.

Horizon included the data in a filing for approval it sent to the FDA earlier this year. The FDA put the filing on its fast track, setting Horizon up to learn whether it has won approval by March.

Securing approval would give Horizon the chance to recoup its investment in teprotumumab. Horizon picked up the drug in 2017 when it acquired River Vision for $145m (£114m) upfront. At that time, Horizon predicted teprotumumab could generate peak US sales in excess of $250m.