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).