San Diego’s Vital Therapies on Sept. 12 scrapped a cell-based therapy intended to treat acute liver failure following final-stage clinical trials, sending the company’s stock plummeting.

Based on the results, the company said it does not believe its treatment will be approved in the U.S. or European Union without additional clinical trials, which would demand plenty of capital and time.

“Although we did not achieve the outcome we were hoping for, we would like to thank those who made this trial possible, including our investigators and their staffs, the patients who were enrolled and their families, and all Vital Therapies employees,” said CEO Russell J. Cox.

The study failed to meet a primary endpoint – or goal – of a significant improvement in overall survival through 91 days.

Vital’s stock on Sept. 13 closed at $0.50 a share, down 92 percent from two days prior.