Updated from 8:54 a.m. EDT
Protein Design Labs'
shares fell sharply Monday after the biotech company reported disappointing test results for its colitis treatment.
The Fremont, Calif.-based company Sunday said it no longer plans to develop daclizumab as a treatment for ulcerative colitis after phase II clinical trials failed to achieve the desired effect.
Daclizumab is the first humanized antibody to gain U.S. regulatory approval. The FDA approved daclizumab for use in transplantation in December 1997, and is currently marketed as Zenapax by
for prevention of acute rejection in kidney transplantation.
The company said it will continue to develop daclizumab as a treatment for other problems, including chronic, persistent asthma and multiple sclerosis.
Recently, shares were down $2.14, or 9.6%, to $20.13.