Longeveron shares plunge 57% after stem-cell therapy fails in mid-stage heart trial

Longeveron announced that its investigational stem cell product, laromestrocel, did not meet its primary endpoint in a Phase 2b study of infants with hypoplastic left heart syndrome (HLHS). The trial, called ELPIS II, enrolled 40 patients and aimed to improve cardiac blood flow.

The failure caused the company's stock to tumble about 57% in pre‑market trading, leaving shares at roughly $2.86. The biotech disclosed it has just over $10 million in cash to fund operations through year‑end.

CEO Stephen Willard said the company will conduct a strategic review of all options to maximize shareholder value and will continue to explore laromestrocel in other indications, including longevity research.

HLHS is a rare congenital defect affecting roughly one in 3,846 newborns in the United States, typically requiring surgery shortly after birth. The negative readout underscores the challenges of developing cell‑based therapies for such high‑risk pediatric conditions.