MIAMI — September 16, 2026
Longeveron Inc. announced topline results from its Phase 2b ELPIS II clinical trial evaluating investigational laromestrocel as an adjunct to Stage 2 palliative surgery in infants with hypoplastic left heart syndrome (HLHS). The trial did not meet its primary endpoint of improvement in right ventricular ejection fraction (RVEF) at Month 12. In the intent-to-treat population, the least-squares mean difference between treatment groups was −0.7 percentage points with a 95% confidence interval of −7.3 to 5.9 and a p-value of 0.8336. The randomized, double-blind study enrolled 40 infants, with patients receiving either a single intramyocardial dose of laromestrocel during Stage 2 surgery or standard-of-care surgery alone. Longeveron said it is continuing to analyze the complete dataset and plans to discuss the exploratory findings with the U.S. Food and Drug Administration (FDA) to determine potential next steps for the HLHS program.
Exploratory Outcomes and Safety Support Further Analysis
Although ELPIS II did not achieve its primary efficacy endpoint, Longeveron reported several exploratory clinical outcomes that it intends to evaluate further. In the as-treated population, there were no deaths over 12 months among patients who received laromestrocel, compared with one death in the control group. During long-term follow-up of transplant-free survival of up to five years across participants, one event occurred among 17 laromestrocel-treated patients compared with two events among 21 standard-of-care patients. Hospitalization burden was similar between groups, while adjudicated Major Adverse Cardiovascular Events (MACE) were approximately 31% lower in the laromestrocel arm, although the negative binomial analysis was not statistically significant. A sponsor-defined exploratory composite endpoint combining all-cause mortality and inpatient hospitalization duration also did not reach statistical significance in the intent-to-treat population. Laromestrocel maintained a safety profile generally consistent with previous clinical experience, with no new safety signals identified and no treatment-emergent adverse events or serious adverse events assessed by investigators as related to the therapy.
FDA Discussions to Guide HLHS Development Path
Longeveron plans to engage with the FDA regarding the ELPIS II findings and the potential regulatory path for laromestrocel in HLHS. The FDA had previously advised the company that RVEF alone would not be sufficient to demonstrate efficacy for regulatory approval and had indicated a willingness to meet following completion of the study to discuss the results and potential development pathways. ELPIS II was conducted in collaboration with the National Heart, Lung, and Blood Institute (NHLBI) through NIH funding and was designed to assess whether laromestrocel administered during Stage 2 palliative surgery could improve cardiac outcomes in infants with HLHS. The condition affects approximately 1,000 infants annually in the United States and requires a complex staged surgical reconstruction process. Longeveron said the company will complete additional analyses before determining its next steps in HLHS, while the reported clinical outcomes and long-term follow-up data will form part of its discussions with regulators.
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Longeveron Evaluates Strategic Options and Aging Pipeline
The ELPIS II results are also shaping Longeveron’s broader corporate strategy, as the company evaluates cost-containment measures and explores options intended to maximize shareholder value. Longeveron said it plans to engage an investment bank as a strategic advisor while pursuing potential funding sources and revenue opportunities for laromestrocel in longevity and Aging-related Frailty. Previous Phase 2b results in Aging-related Frailty showed improvements in physical condition after nine months compared with placebo, with the findings published in Cell Stem Cell in February 2026. The company was also selected as a Milestone 2 Awardee team in the XPRIZE Healthspan competition and received a $1 million milestone award toward the future competition clinical trial. Laromestrocel development programs have received five FDA designations across HLHS and Alzheimer’s disease. As Longeveron evaluates the ELPIS II dataset and engages the FDA on potential HLHS next steps, the company is simultaneously prioritizing cost containment and exploring opportunities to advance laromestrocel in aging-related and other regenerative medicine programs.
Source:Longeveron,, press release
