PHILADELPHIA, PA — iECURE, Inc. reported preliminary clinical data showing its experimental gene-editing therapy reduced life-threatening metabolic crises in infants with severe ornithine transcarbamylase deficiency, offering early evidence of efficacy in a rare pediatric disorder with limited treatment options.
Data presented at the American Society of Gene & Cell Therapy annual meeting showed that 71% of treated participants experienced no hyperammonemic crises following administration of ECUR-506, while the annualized rate of those crises fell by about 52% across the first three dosing cohorts in the ongoing OTC-HOPE trial.
The findings are based on seven participants as of an April 20, 2026 cutoff date.
Ornithine transcarbamylase deficiency is a rare inherited disorder that prevents the body from properly removing ammonia from the bloodstream. The resulting hyperammonemic crises, defined in the trial as ammonia levels above 100 µmol/L accompanied by neurologic changes, can lead to hospitalization, brain injury, or death.
The study included three participants in the low-dose cohort, three in the intermediate-dose cohort, and one participant in the high-dose group.
According to the company, five of seven participants experienced no hyperammonemic crises after treatment. Researchers also observed a decline in the annualized crisis rate from about 3.12 events per year before treatment to roughly 1.49 afterward.
The company indicated post-treatment outcomes reflected a combination of ECUR-506 therapy and continued standard-of-care management, including ammonia-scavenging drugs and strict dietary controls.
The therapy was generally well tolerated across all dose groups, with no unexpected safety events reported.
No infusion-related reactions or thrombotic microangiopathy cases were observed, and patients did not receive preventative immunosuppression before treatment.
Five of seven participants experienced asymptomatic liver enzyme elevations, classified as Grade 2 or 3 transaminitis, which investigators managed with reactive immunosuppression.
One participant died from hypoxemic respiratory failure that investigators determined was unrelated to ECUR-506 and attributable to complications from the underlying disease.
“HACs, particularly those associated with neurologic symptoms, are the primary driver of morbidity and mortality in infants with neonatal-onset OTC deficiency,” Margo Sheck Breilyn, an assistant professor at the Icahn School of Medicine at Mount Sinai, noted in the release. She added that reducing those events “can have a meaningful impact on clinical outcomes and long-term neurodevelopment.”
Chief Executive Joseph Truitt described the findings as early evidence of clinical activity in a high-risk patient population and stated the company is working with regulators as it advances dose selection for a pivotal cohort.
The data remain preliminary, and the trial continues with additional follow-up intended to assess durability and longer-term outcomes.
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