Ultragenyx's Neurogenetic Disorder Candidate Shows Favorable Tolerability, Clinical Activity

Ultragenyx Pharmaceutical Inc RARE and GeneTx Biotherapeutics LLC announced interim data from the Phase 1/2 study in pediatric patients with a genetically confirmed diagnosis of full maternal UBE3A gene deletion.
Interim results demonstrate a meaningful improvement in clinical disease and an acceptable safety profile.
7/9 patients showed improvement on the disease scale from Baseline in at least 3 of 5 domains and the overall score.
Six patients exhibited a decrease in severity in at least 2 of 5 domains and the overall score.
Also See: Ultragenyx Sells One-Third Of Future North American Crysvita Royalties For $500M.
There have been no treatment-related serious adverse events of any type nor adverse events related to lower extremity weakness observed in these patients.
Cerebrospinal fluid (CSF) protein levels have remained stable.
These interim data support a protocol amendment to the Phase 1/2 study approved in the U.K. and Canada to initiate additional new cohorts of patients at higher monthly loading doses.
The study has begun enrollment and has dosed the first patient in these new cohorts.
Ultragenyx also announced it has exercised its option to acquire GeneTx and has closed on the acquisition for an upfront payment of $75.0 million plus future milestone and royalty payments.
Price Action: RARE shares closed 5.76% lower at $61.02 on Monday.