Clinical data released yesterday showed that Elan's Antegren drug proved superior to a placebo in maintenance trials for the treatment of Crohn's disease.
The data, released ahead of a conference on digestive diseases in the US next week, showed that, at six months, 61 per cent of patients on Antegren maintained a clinical response compared to 29 per cent for the placebo group.
The 339-person study also found that 44 per cent of the Antegren group maintained clinical remission compared with 26 per cent of the placebo group.
Analysts said the data supported the use of Antegren for maintenance use in the treatment of Crohn's but was not compelling enough to support a filing with the US Food and Drug Administration (FDA).
Instead, the company was likely to have to proceed with plans to undertake a revised induction trial before it sought approval for use of the drug to treat Crohn's.
"While the data would suggest that Antegren will play a part in the treatment of Crohn's, particularly in maintenance, we believe that it will be regulated to being a second-line treatment for the condition," says Mr Peter Frawley, analyst at Merrion Stockbrokers.
"That said, Antegren's good safety profile should ensure that it will play a part in the treatment of the disease."
Elan, which is developing the drug along with Biogen Idec, is primarily focusing on Antegren as a treatment for multiple sclerosis. Its use in the treatment of Crohn's is seen as a bonus.
Elan shares fell 6.38 per cent to $19.66 in New York yesterday in a generally weaker market. In Dublin, they closed 10 per cent lower at €16.39.
