Ultragenyx reports interim Phase I/II data for DTX301 in OTC deficiency

Ultragenyx Pharmaceutical Inc. (NASDAQ:RARE) reported interim data from three evaluable patients in the first cohort of a Phase I/II trial evaluating a single peripheral IV infusion of 2x10¹² GC/kg DTX301 to treat ornithine transcarbamylase (OTC) deficiency. In the first patient, DTX301 increased the rate of ureagenesis -- the pathway for the metabolism of ammonia -- by 30% from baseline to week 12. The second patient did not show a clinically meaningful change in the rate of ureagenesis over the 12-week period, while the third patient showed a "modest" increase on the endpoint from baseline to week six. No infusion-related or serious adverse events were reported.

Ultragenyx said the dose evaluated in the first dose cohort is at the low end of the expected therapeutic range. Data are expected next half from the second dose cohort evaluating a single peripheral IV infusion of 6x10¹² GC/kg DTX301...