Philadelphia, August 20, 2026
iECURE announced that updated clinical data from the ongoing OTC-HOPE trial of ECUR-506 in infants with neonatal-onset ornithine transcarbamylase (OTC) deficiency will be presented at the Annual Symposium of the Society for the Study of Inborn Errors of Metabolism (SSIEM) in Helsinki, Finland. The company said the oral presentation will include updated safety observations, genome editing data from the low-dose cohort and analyses examining metabolic control following administration of ECUR-506. Additional analyses are expected to evaluate the relationship between baseline disease severity and clinical response, providing further information on how disease characteristics may influence outcomes in the ongoing first-in-human study. The presentation, titled “Decreased rate of hyperammonemic crises in infants with neonatal-onset OTC deficiency post ECUR-506 administration,” is scheduled for August 27, 2026, during the SSIEM annual meeting. The data presentation represents an important clinical-development update for iECURE as the company continues evaluating its in vivo targeted gene insertion approach in a severe inherited neurometabolic disorder. For cGxP.wire readers, the key development is the planned disclosure of additional clinical and genome-editing observations from an ongoing trial rather than a new regulatory approval or completed efficacy study. The program remains investigational, with further follow-up required to establish the durability, safety and clinical significance of the treatment.
ECUR-506 Data to Highlight Metabolic Control
The OTC-HOPE Phase 1 clinical trial is evaluating ECUR-506 in male infants with genetically confirmed neonatal-onset OTC deficiency, a rare inherited disorder caused by mutations affecting the ornithine transcarbamylase enzyme in the liver. The upcoming SSIEM presentation is expected to provide updated information from the ongoing study, including safety findings and metabolic-control measures from the low-dose cohort. Investigators will also examine whether baseline disease severity is associated with differences in clinical response. These analyses are particularly relevant in neonatal-onset OTC deficiency because severe disease can emerge shortly after birth and may result in recurrent hyperammonemic crises, which occur when ammonia accumulates in the bloodstream to toxic levels. Such crises can cause neurological injury and can become life-threatening without effective management. Current disease management commonly involves protein restriction and ammonia-scavenging medications, which can help control ammonia levels but require ongoing treatment and do not eliminate the risk of metabolic decompensation. Against this background, the clinical development strategy for ECUR-506 is focused on addressing the underlying genetic cause rather than relying solely on chronic metabolic management. The upcoming clinical data will therefore be important for assessing whether genome editing can produce measurable biological and clinical effects in this high-risk infant population.
iECURE Advances In Vivo Gene Insertion Approach
ECUR-506 is an investigational in vivo targeted gene insertion therapy designed to restore OTC enzyme activity in liver cells. The approach uses two adeno-associated virus (AAV) vectors containing different components of the gene-editing system. One vector delivers an ARCUS nuclease designed to create an insertion site within the PCSK9 gene locus, while the second delivers a functional copy of the OTC gene intended for targeted insertion at that location. By inserting a functional OTC gene into liver cells, iECURE aims to enable production of the missing or dysfunctional enzyme and potentially provide durable gene expression. The company describes the approach as variant-agnostic, meaning the therapeutic strategy is intended to address multiple disease-causing OTC variants rather than requiring an individualized treatment for each mutation. The ARCUS nuclease used in ECUR-506 has been licensed by iECURE from Precision BioSciences. Importantly, the therapy remains under clinical investigation, and the available information does not establish long-term efficacy or safety. The ongoing OTC-HOPE study is therefore central to understanding whether the targeted gene-insertion mechanism can achieve sufficient editing, enzyme restoration and metabolic control while maintaining an acceptable safety profile. Clinical evidence from the trial will determine how effectively the platform translates its genetic mechanism into patient benefit.
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OTC-HOPE Provides Early Clinical Evidence
The OTC-HOPE study is a first-in-human clinical trial assessing the safety, tolerability and efficacy of a single intravenous dose of ECUR-506 in eligible male infants up to seven months of age with severe neonatal-onset OTC deficiency. The study includes evaluation of pharmacokinetics, disease-specific biological markers, clinical outcomes, developmental milestones and quality-of-life measures. Following the main six-month study period, participants are expected to transition into a 14.5-year long-term follow-up study, reflecting the need for extended monitoring following an investigational genome-editing therapy. The upcoming SSIEM presentation will provide another clinical snapshot as iECURE continues to collect data from the program. For the broader gene-editing and rare-disease development landscape, the program is notable because it is testing a targeted gene-insertion strategy directly in patients during infancy, when uncontrolled hyperammonemia can cause severe and irreversible complications. The company is also developing additional investigational programs for inherited neurometabolic disorders, including citrullinemia type 1 and phenylketonuria. The immediate focus, however, remains ECUR-506 and the evidence emerging from OTC-HOPE, with safety, genome-editing activity and metabolic outcomes expected to shape the next stages of development for the therapy in neonatal-onset OTC deficiency.
Source:iECURE,press relese
