Lomecel-B Delivered During Stage II Surgery for Hypoplastic Left Heart Syndrome (ELPIS)

This study is designed to assess the safety, tolerability, and efficacy of Lomecel-B (formerly LMSCs) as an adjunct therapy to the standard stage II (BDCPA) surgical intervention for HLHS, which is typically performed at 4 - 6 months after birth. Lomecel-B will be delivered via intramyocardial injections. A total of 30 patients will be enrolled in 2 stages with 3 Cohorts. In the first stage, 10 consecutive HLHS patients will be enrolled and treated with Lomecel-B (Cohort A). The first 3 patients will be treated no less than 5 days apart, and will be evaluated for any treatment-emergent adverse events (TE-AEs) (e.g., induced myocardial infarction or perforation). These patients will undergo full evaluation for 5 days to demonstrate safety prior to proceeding with the remainder of the cohort. After 6 months post-treatment of the last patient of Cohort A, a formal safety review will be conducted prior to proceeding to the next phase. The second stage is double-blinded, in which 20 HLHS patients will be randomized to either receive treatment with Lomecel-B (Cohort B, 10 patients), or will receive no cells and no injection (Cohort C, 10 patients).