NEW YORK (TheStreet) -- Athersys (ATHX) - Get Report plummeted more than 55% to a one-year low of $1.09 on Monday after the biotechnology company announced that its experimental stem-cell therapy to treat the inflammatory bowel disease ulcerative colitis did not show any benefits in patients in a mid-stage trial.

Athersys' partner Pfizer (PFE) - Get Report conducted the trial, in which the therapy did not show a statistically significant decrease in the severity of ulcerative colitis in patients with moderate to severe cases of the disease when compared to a placebo. The therapy also did not significantly reduce rectal bleeding when compared to a placebo.

Must Read:Warren Buffett's 10 Favorite Growth Stocks

STOCKS TO BUY: TheStreet Quant Ratings has identified a handful of stocks that can potentially TRIPLE in the next 12 months. Learn more.

Image placeholder title

ATHX data by YCharts

STOCKS TO BUY: TheStreet's Stocks Under $10 has identified a handful of stocks that can potentially TRIPLE in the next 12-months. Learn more.

Editor's Note: Any reference to TheStreet Ratings and its underlying recommendation does not reflect the opinion of TheStreet, Inc. or any of its contributors including Jim Cramer or Stephanie Link.