Precision BioSciences, Inc. announced that its partner iECURE has received approval from the U.K. Medicines & Healthcare products Regulatory Agency (MHRA) for the company?s Clinical Trial Authorization (CTA) application to expand the Phase 1/2 OTC-HOPE study evaluating ECUR-506 into the U.K. The OTC-HOPE study is investigating ECUR-506, incorporating an ARCUS nuclease, for the treatment of Ornithine Transcarbamylase (OTC) deficiency in infants. The CTA approval by the MHRA follows the previous approval to begin the OTC-HOPE study by the Australian Therapeutic Goods Administration (TGA). In 2021, Precision licensed to iECURE an ARCUS nuclease that inserts a functional copy of the OTC gene for treatment of OTC deficiency.

OTC deficiency, the most common urea cycle disorder, is an inherited metabolic disorder caused by a genetic defect in a liver enzyme responsible for the detoxification of ammonia. Individuals with OTC deficiency can build up excessive levels of ammonia in their blood potentially resulting in devastating consequences, including irreversible neurological damage, coma, and death. The severe form of the condition emerges shortly after birth and is more common in boys than girls.

The only corrective treatment for early onset severe OTC deficiency is a liver transplant. Currently available medical therapies do not correct the disease and do not eliminate the risk of life-threatening symptoms or crises.