Dimension doses first patient in Phase I/II trial of DTX301 for OTC deficiency


US-based biopharmaceutical firm Dimension Therapeutics has started dosing patients in a Phase I/II clinical trial of DTX301 to treat ornithine transcarbamylase (OTC) deficiency.

DTX301 is an adeno-associated virus (AAV) gene therapy being developed to deliver stable expression and activity of OTC with a single intravenous (IV) infusion to prevent or minimise the incidence of OTC deficiency-associated complications.

The company secured orphan drug designation for DTX301 in the US in January last year, as well as in Europe during March last year.

The global, multi-centre, open-label, dose-finding Phase I/II trial will evaluate safety of single ascending DTX301 doses in adults with late-onset OTC deficiency.

Patient enrolment for the trial is being carried out at 12 centres in the US, the UK, Spain and Canada.

"We believe that DTX301, based on our differentiated AAV8 platform in IMD, holds great promise for addressing the unmet need among patients, and we look forward to the continued advancement of the trial."

Dimension Therapeutics CEO Annalisa Jenkins said: “OTC deficiency is an inherited metabolic disease (IMD), for which approved therapies are unable to eliminate the risk of metabolic crises from elevated ammonia.

“We believe that DTX301, based on our differentiated AAV8 platform in IMD, holds great promise for addressing the unmet need among patients, and we look forward to the continued advancement of the trial.”

The Phase I/II trial will monitor measures for OTC deficiency disease status and hepatocyte (liver) ureagenesis capacity such as ammonia levels and 13C-acetate to determine DTX301’s therapeutic response.

As per the current trial progress, it is estimated that the initial clinical results will be available later this year.

During preclinical studies, DTX301 is reported to have demonstrated potential for favourable tolerability and efficacy profile for the treatment of OTC deficiency.