Precision BioSciences Announces Complete Clinical Response in First Infant Dosed by Partner iECURE in Ongoing Phase 1/2 Clinical Trial in Ornithine Transcarbamylase (OTC) Deficiency

In This Article:

- Treatment with ECUR-506 resulted in a complete clinical response from three months post exposure to the end of study (six months post exposure)

- ECUR-506 was generally well tolerated with no significant clinical safety concerns

- Insertion of a functional OTC gene through ARCUS in vivo gene editing may provide lasting clinical benefit for children with OTC deficiency who are in dire need of effective treatments

DURHAM, N.C., January 09, 2025--(BUSINESS WIRE)--Precision BioSciences, Inc. (Nasdaq: DTIL), a clinical stage gene editing company utilizing its novel proprietary ARCUS® platform to develop in vivo gene editing therapies for sophisticated gene edits, including gene insertion, excision, and elimination, today announced that its partner iECURE has reported clinical efficacy and safety data in the first patient dosed with ECUR-506 in the Phase 1/2 OTC-HOPE study. ECUR-506 is iECURE’s in vivo gene insertion program designed to treat neonatal onset Ornithine Transcarbamylase (OTC) deficiency utilizing a PCSK9-specific ARCUS nuclease, licensed from Precision, that enables insertion of a functional copy of the OTC gene.

"Congratulations to iECURE for these exciting results and initial clinical validation in the first infant dosed in their OTC-HOPE trial. These results showcase that a complete clinical response can be achieved through in vivo gene editing for children born with this devastating genetic disease," said Michael Amoroso, Chief Executive Officer of Precision BioSciences. "The data increases our confidence in the therapeutic potential of ARCUS as a novel in vivo gene editing approach for patients who have been and plan to be treated in clinical trials by Precision and partners."

Treatment with ECUR-506, which employs an ARCUS® nuclease licensed from Precision BioSciences, was generally well tolerated in this infant with no significant clinical safety concerns apart from asymptomatic transaminitis at four weeks. The asymptomatic transaminitis was managed with immunosuppressive therapy and resolved within four weeks. Twelve weeks after a single dose of ECUR-506, ammonia scavenger medication was discontinued and mean daily protein intake was increased to age-appropriate levels. Protein liberalization was well tolerated, and the subsequent mean ammonia level remained within normal limits and was reduced compared to the mean pretreatment level. The response was maintained through six months and indicates that a complete response was achieved in this patient.

The OTC-HOPE study is ongoing in the United Kingdom, the United States, Australia, and Spain, and iECURE expects to finish enrollment in 2025 and provide complete data for the program in the first half of 2026.