Ultragenyx Reports Additional Positive Durability Data For DTX401, DTX301 Gene Therapies

(RTTNews) - Ultragenyx Pharmaceutical Inc. (RARE) reported new long-term durability data from the phase 1/2 studies of DTX401 for Glycogen Storage Disease Type Ia and DTX301 for Ornithine Transcarbamylase deficiency.

The additional longer-term phase 1/2 data with DTX401 for Glycogen Storage Disease Type Ia showed durability of response, with sustained responses lasting up to 3 years since treatment. Across all 12 patients, the mean reduction in daily cornstarch intake was 69.9% ranging from 19-100% when comparing baseline to the most recent visit. DTX401 is an investigational adeno-associated virus type 8 gene therapy.

The additional longer-term phase 1/2 data with DTX301 for Ornithine Transcarbamylase Deficiency showed durable metabolic control and sustained responses. The six patients who previously demonstrated a response remain clinically and metabolically stable, including all three treated at the highest dose. DTX301 is an investigational AAV type 8 gene therapy.