- Thursday was Rare Disease Day in the U.S., which made all the more timely the announcement that a Horizon Pharma drug met the primary endpoint of a Phase 3 trial testing it in an uncommon condition known as active thyroid eye disease (TED). The positive results pushed up the Irish company's share price more than 30%.
- Over 80% of the patients who took teprotumumab had an reduction in bulging of the eye of 2 millimeters or more, compared with just 10% of patients treated with placebo. All secondary endpoints were met and Horizon said the safety profile was consistent with other studies.
- Teprotumumab has Breakthrough Therapy, Orphan Drug and Fast Track designations in the U.S. Horizon plans to submit a Biologics License Application to the Food and Drug Administration in mid-2019. The company's share price hit a 52-week high of $29.44 on Thursday, before giving back about 3% Friday.
In thyroid eye disease, inflammation in the tissue behind the eyes causes symptoms like bulging eyes (proptosis), double vision and, in rare cases, blindness. The disease affects between 15,000 and 20,000 people a year in the U.S. and is currently treated by surgery as there is no FDA-approved therapeutic.
"Teprotumumab had a dramatic impact on proptosis, and has potential to be a disease-modifying therapy," Shao-Lee Lin, Horizon's chief scientific officer, said on a Feb. 28 call.
Horizon's new clinical victory also carries weight given its relatively thin late-stage pipeline. Teprotumumab, which Horizon picked up when it acquired River Vision Development in May 2017, has gone through Phase 3 testing, but three other projects — all in gout — are in preclinical development.
During an earnings call in early 2017, Horizon said it would continue to consider bolt-on acquisitions and licensing deals. However, the only deal since that time has been a collaboration with HemoShear Therapeutics.
A successful launch for teprotumumab would provide the company with fresh revenue. Horizon recorded $958.7 million in cash and cash equivalents as of Dec. 31, 2018.