Experimental Alzheimer's drug ELND005, at its mid-stage clinical trial, causes 9 deaths, forcing the pharma companies involved to drop the medicine all together. A product of Elan Corp and Transition Therapeutics Inc., the drug was soon to be launched in the markets. But doubts have been raised on this issue now.

The shares of both are being affected after this incident where Transition Therapeutics Inc. saw an all time low situation since 2002, and a fall of 2.3% was recorded by Elan shares. 

The study was being conducted on around 353 patients divided in four groups; three groups were given different dose levels of ELND005 whereas one group was given a placebo. The patients are in serious conditions and 9 deaths have also been recorded for those who were given two highest dose levels.

Jack Gorman, an analyst at Davy Stockbrokers, said that the news of the deaths in patients on high doses considerably increased the perceived risk of the medicine reaching the market.

Elan along with Johnson & Johnson is developing one more Alzheimer's drug named as Bapineuzumab; it is also in final-stage clinical trials. The company dropped the idea of higher doses as a safety measure.