CV Therapeutics said on Tuesday its angina drug Ranexa was not effective in a study of acute and long-term treatment of patients with a type of heart disease known as acute coronary syndrome.
Shares of the pharmaceutical concern lost more than a quarter of their value in after-market trading, falling to the $9 range.
There was no adverse trend in death or arrhythmias in patients taking the drug, also known by the chemical name ranolazine, the company said.
CV Therapeutics said it believes the data could support expansion of Ranexa's approved uses to include the drug as a first choice treatment for angina. It is currently approved to treat chronic angina in patients who have not achieved an adequate response with other drugs.