The ISEQ Index dropped 31.37 points yesterday to close at 3,177.53.

ELAN — which earlier this week announced tentative plans to partner with an international pharmaceutical company to boost its Alzheimer’s treatment roll-out — has won a significant US patent for one of its in-trial treatments for that condition.

SHARES in Elan — the Dublin-headquartered pharmaceutical firm — fell by nearly 5% yesterday after it announced a significant amendment to trials of its leading test treatment for Alzheimer’s disease and analysts reduced their faith in the drug making it to market.

Pharmaceutical giant Elan have announced that it has engaged Citigroup to conduct "a review of the company's strategic alternatives" in order to secure enough financial resources and commercial infrastructure to allow Elan to develop its portfolio.