ECUR-506 - (OTC-HOPE)

April 20, 2026: iECURE reported preliminary ASGCT data from the ongoing first-in-human OTC-HOPE trial of ECUR-506 in male infants with neonatal-onset ornithine transcarbamylase (OTC) deficiency. Across 7 participants in the low, intermediate, and first high-dose cohorts, 71% (5/7) had no post-treatment hyperammonemic crises (HACs), and the annualized HAC rate fell about 52% (from ~3.12 to ~1.49 events/year) after a single ECUR-506 dose; there was also a 60% reduction in the number of participants experiencing a HAC.

ECUR-506 was described as generally well tolerated, with no unexpected safety events, no infusion-related reactions, no thrombotic microangiopathy, and no prophylactic immunosuppression. Asymptomatic Grade 2-3 transaminitis occurred in 5/7 participants, was managed with reactive immunosuppression, and did not recur after taper. One death from hypoxemic respiratory failure was assessed as unrelated to ECUR-506 and due to underlying disease complications.

The company said the findings provide early proof of concept and support continued evaluation. iECURE plans to complete treatment of the highest-dose cohort to support dose selection for a pivotal cohort. Additional efficacy data from the completed low-dose cohort are planned for presentation at the SIMD 2026 Annual Meeting on May 17-20, 2026.