Horizon secures FDA priority review for teprotumumab for treatment of active thyroid eye disease

Horizon Therapeutics plc announced that the U.S. Food and Drug Administration (FDA) has accepted the Biologics License Application (BLA) for teprotumumab, an investigational medicine for the treatment of active thyroid eye disease (TED), and granted it Priority Review designation. The FDA grants Priority Review designation to applications for medicines that have the potential to provide significant improvements in the treatment of serious conditions. Priority Review is associated with an accelerated six-month review period compared to the standard ten-month review period. If approved, teprotumumab would be the first FDA-approved medicine for the treatment of active TED.

“Priority Review for the teprotumumab BLA is another positive step toward our goal to make a difference in the lives of people who are living with active TED – a painful, debilitating and vision-threatening rare disease,” said Timothy Walbert, chairman, president and chief executive officer, Horizon. “The accelerated review timeline is particularly important given that there is no FDA-approved medical treatment for TED and the window of time for treatment is limited before patients experience potentially long-term, permanent damage to their eyes.”

The FDA has completed its filing review and determined that the application is sufficiently complete to permit a substantive review. Therefore, a priority review classification was established and the Prescription Drug User Fee Act (PDUFA) goal date is March 8, 2020. In its letter, the FDA noted that it has established internal review timelines for FDA internal milestone meetings (e.g., filing, planning, mid-cycle, team and wrap-up meetings) and that these timelines described in current FDA guidelines are flexible and subject to change based on workload and other potential review issues (e.g., submission of amendments). The letter further notes that the FDA will inform Horizon of any necessary information requests or status updates following the milestone meetings or at other times, as needed, during the process. If major deficiencies are not identified during the review, the FDA plans to communicate proposed labeling and, if necessary, any post marketing requirement/commitment requests by late December 2019.

The FDA also indicated that it is currently planning to hold an advisory committee meeting to discuss the application per guidelines for new molecular entities. Additionally, the FDA notified Horizon that, at this time, it has not identified any potential review issues, although its current filing review is only a preliminary evaluation of the application and is not indicative of deficiencies that may be identified during the review.

The accepted BLA for teprotumumab includes results from the Phase 3 confirmatory clinical trial, called OPTIC (Treatment of Graves’ Orbitopathy (Thyroid Eye Disease) to Reduce Proptosis with Teprotumumab Infusions in a Randomized, Placebo-Controlled, Clinical Study), as well as positive Phase 2 results. The OPTIC study found that significantly more patients treated with teprotumumab had a meaningful improvement in proptosis, or bulging of the eye, as compared with placebo (82.9% of teprotumumab patients compared to 9.5% of placebo patients). All secondary endpoints were also met, including reduced diplopia (double vision), improved quality of life (QoL) and reductions in Clinical Activity Score (CAS). Teprotumumab was generally well tolerated; the majority of adverse events were mild or moderate, manageable and resolved during or after treatment. Results of the OPTIC study were presented during the 2019 American Association of Clinical Endocrinologists (AACE) Annual Scientific & Clinical Congress. The OPTIC study was initiated after the Phase 2 study demonstrated clinically meaningful and highly statistically significant results in reducing proptosis and in the symptoms of active TED (pain, swelling, redness and inflammation) as measured by Overall Treatment Response (combined CAS and proptosis improvement). The Phase 2 study was published in The New England Journal of Medicine in May 2017.