Overview

Safety and Dose-Finding Study of DTX301 (scAAV8OTC) in Adults With Late-Onset OTC Deficiency

Status:
Active, not recruiting
Trial end date:
2021-12-01
Target enrollment:
0
Participant gender:
All
Summary
A Phase 1/2, open-label dose-finding safety study of single ascending doses of DTX301 in adults with late-onset OTC Deficiency
Phase:
Phase 1/Phase 2
Accepts Healthy Volunteers?
No
Details
Lead Sponsor:
Ultragenyx Pharmaceutical Inc
Treatments:
Prednisolone
Prednisone
Criteria
Key Inclusion Criteria:

1. Males and females ≥18 years of age with documented diagnosis of late onset (defined as
first manifestation of signs and symptoms at ≥1 month of age) OTC deficiency,
confirmed via enzymatic, biochemical, or molecular testing

2. Documented history of ≥1 symptomatic hyperammonemia event with ammonia ≥100 µmol/L.

3. Subject's OTC deficiency is stable as evidenced by either a) no clinical symptoms of
hyperammonemia OR b) an ammonia level <100 µmol/L within the 4 week period preceding
the Screening visit.

4. On ongoing daily stable dose of ammonia scavenger therapy for ≥4 weeks.

5. Males and all females of childbearing potential must be willing to use effective
contraception at the time of administration of gene transfer and for the 52 weeks
following administration of DTX301

Key Exclusion Criteria:

1. At Screening or Baseline (Day 0), plasma ammonia level ≥ 100 μmol/L for patients who
historically maintain normal ammonia levels; OR plasma ammonia level ≥ 200 μmol/L for
patients who historically are not able to fully control ammonia levels with baseline
management; OR signs and symptoms of hyperammonemia.

2. Liver transplant, including hepatocyte cell therapy/transplant.

3. History of liver disease

4. Significant hepatic inflammation or cirrhosis

5. Serum creatinine >2.0 mg/dL.

6. Participation in another investigational medicine study (including another gene
transfer trial) within 3 months of Screening

7. Pregnant or nursing

Note additional inclusion/exclusion criteria may apply, per protocol.