DTX 301 for OTC

DTX 301 is an investigational AAV gene therapy being developed for the treatment of individuals with ornithine transcarbamylase (OTC) deficiency. DTX301 is designed to deliver OTC gene expression in a durable fashion, with the goal of preventing or reducing the occurrence of complications associated with OTC deficiency.

OTC deficiency, the most common urea cycle disorder, is caused by a genetic defect in a liver enzyme responsible for detoxification of ammonia. Individuals with OTC deficiency can build up excessive levels of ammonia in their blood, potentially resulting in neurological deficits and other toxicities. It is estimated that more than 10,000 patients are affected by OTC deficiency worldwide, of which approximately 80% are classified as late-onset. The greatest percentage of patients, including males and females, experience late-onset disease, representing a clinical spectrum of disease severity. Neonatal onset disease occurs in males, presents as severe disease, and can be fatal at an early age. Approved therapies, which must be taken multiple times a day for the patient's entire life, do not eliminate the risk of future metabolic crises. Currently, the only curative approach is liver transplantation.

Clinical Trials

For more information on the ongoing Phase 1/2 study of DTX301 in patients with OTC deficiency, please visit the study page.

DTX 301 for OTC


Phase 1/2


Ornithine Transcarbamylase (OTC) Deficiency


8,000 patients worldwide        (Late-onset)

disease mechanism

Genetic defect in ammonia detoxification


Adverse cognitive & neurological effects

Treatment mechanism

Deliver ornithine transcarbamylase gene expression