Longeveron Inc. (NASDAQ: LGVN) announced on September 16, 2026, that its Phase 2b clinical trial, ELPIS II, failed to meet its primary efficacy endpoint. The trial evaluated laromestrocel, an investigational stem cell therapy, as an adjunct to Stage 2 palliative surgery in 40 infants with hypoplastic left heart syndrome (HLHS).
The primary endpoint was the change in right ventricular ejection fraction (RVEF) at Month 12. In the intent-to-treat population, the least-squares mean difference between the treatment and control groups was -0.7 percentage points (95% confidence interval: -7.3 to 5.9; p=0.8336).
Despite the failure of the primary endpoint, the company noted exploratory clinical outcomes that are being analyzed. In the as-treated group over a 12-month period, there were no deaths among patients receiving laromestrocel, compared to one death in the control group. Additionally, the laromestrocel arm had one event (out of 17 patients) versus two events (out of 21 patients) regarding transplant-free survival in long-term follow-up. Adjudicated Major Adverse Cardiovascular Events (MACE) were approximately 31% fewer in the laromestrocel arm (12 events vs. 19 events), though this difference was not statistically significant.
The company reported that laromestrocel maintained a safety profile consistent with prior trials, with 644 participants treated across its programs. Treatment-emergent adverse events and serious adverse events were reported in 94.1% and 64.7% of treated participants, respectively, compared to 100% and 71.4% in the control group. No new safety signals were identified.
Longeveron stated it will discuss the results with the U.S. Food and Drug Administration (FDA) to determine a potential path forward. The company also announced it has initiated a process to review all options with the goal of maximizing shareholder value, including engaging an investment bank and implementing cash conservation measures.
The company continues to pursue funding for laromestrocel in longevity and Aging-related Frailty, where it has published results in Cell Stem Cell and was selected as a Milestone 2 Awardee in the XPRIZE Healthspan competition.
