FDA, Ultragenyx Settle OTC Phase 3 Study Design
At an FDA/Untragenyx end-of-Phase-2 meeting for the DTX301 ornithine transcarbamylase (OTC) deficiency gene therapy program, the parties reached an agreement on the design and endpoints for a Phase 3 study. The company says the study will include a 64-week primary efficacy analysis period and enroll about 50 patients 12 years of age and older. The co-primary endpoints are a change in 24-hour plasma ammonia levels and the percent of patients who achieve a response as measured by discontinuation or reduction in baseline disease management.
The Phase 3 study is expected to begin dosing in the second half of 2021, Ultragenyx says.