Gilead, Elan and Transition Therapeutics Halt Drug Trials

Just because a drug has managed to successfully meet earlier trial goals, it's no guarantee it will continue to do so. On Tuesday, Gilead, Elan and Transition Therapeutics halted trials of experimental drugs that had previously showed promising results.

Elan Corp. (ELN) and Transition Therapeutics Inc. (TTHI) have partially halted a mid-stage clinical trial of their experimental Alzheimer's drug, ELND005. They said that patients will be immediately withdrawn from the study in the two higher-dose groups of 1,000 milligrams and 2,000 mg twice daily, due to greater rates of serious adverse events in those groups, including nine deaths.