Ultragenyx Discontinues Development of UX007 for Patients with Glut1 DS

Rare Daily Staff

Ultragenyx Pharmaceutical announced its phase 3 study of UX007 in patients with glucose transporter type-1 deficiency syndrome (Glut1 DS) experiencing disabling paroxysmal movement disorders did not achieve its primary endpoint of demonstrating a statistically significant reduction in the frequency of paroxysmal movement events with UX007 treatment compared to placebo, and did not demonstrate a meaningful difference between treatment groups. The study also did not meet its key secondary endpoints. The safety profile observed in this study was consistent with what has been previously reported with UX007.

Based on these results, Ultragenyx plans to discontinue the Glut1 DS development program, and will work with investigators and patients on a reasonable transition plan for patients with Glut1 DS who are still on UX007. The study had enrolled 44 children and adults experiencing disabling paroxysmal movement disorders associated with Glut1 DS.

“We had previously observed significant improvements in individual cases of Glut1 DS with UX007 and so we are particularly disappointed by the results of the Glut1 DS study in a larger group of patients that did not demonstrate this same effect,” said Emil Kakkis, CEO and president of Ultragenyx.

A separate program evaluating UX007 in long-chain fatty oxidation disorders (LC-FAOD) continues on track. The U.S. Food and Drug Administration has accepted the company’s proposal to submit a New Drug Application for UX007 for the treatment of LC-FAOD based on existing data, and a pre-NDA meeting with the FDA will take place before the end of 2018. In the European Union, Ultragenyx will discuss these data with the European Medicines Agency and expects to have an update this year.

October 26, 2018

Photo: Emil Kakkis, CEO and president of Ultragenyx