Longeveron's ELPIS II trial misses primary endpoint in HLHS study

Longeveron Inc. announced on September 16, 2026 that its Phase 2b ELPIS II trial evaluating laromestrocel in infants with hypoplastic left heart syndrome (HLHS) did not meet its primary endpoint of improvement in right ventricular ejection fraction (RVEF) at month 12¹. In the intent-to-treat population, the least-squares mean difference between treatment groups was −0.7 percentage points (95% CI: −7.3 to 5.9; p=0.8336)¹.

The trial tested a single intramyocardial dose of laromestrocel administered during Stage 2 palliative surgery against standard of care alone, in 40 infants with HLHS randomized 1:1, followed for 12 months¹. Some exploratory outcomes favored the treatment arm: over a 12-month period there were no deaths in patients that received laromestrocel, compared to one patient in the control group, and adjudicated Major Adverse Cardiovascular Events were approximately 31% fewer in the laromestrocel arm¹. However, the negative binomial analysis was not statistically significant, and a sponsor-defined exploratory hierarchical composite endpoint of all-cause mortality and hospitalization duration was also not statistically significant in the ITT population¹.

On safety, laromestrocel showed a favorable safety and tolerability profile consistent with prior programs, with treatment-emergent adverse events in 94.1% and serious adverse events in 64.7% of treated participants, versus 100% and 71.4% in controls¹. The company said it plans to discuss the results with the FDA to determine potential next steps for the HLHS program¹.

Separately, Longeveron said it has initiated a process to review all options with the goal of maximizing shareholder value, intends to engage an investment bank as strategic advisor, and will implement cash conservation measures to optimize cost containment¹. The release did not mention a sale as part of this review.