Elan climbs to 6-year high on study results

Elan shares soared $2.89, or 10.7 percent, to close at $30. Earlier in the session, shares traded as high as $30.03, their highest since 2002.

Data released Tuesday showed a study of bapineuzumab, an Alzheimer's drug being developed by Elan and U.S. drug maker Wyeth, did not meet its main goal, but patients lacking a certain gene benefited from the drug compared with a placebo.

About 40 percent to 70 percent of Alzheimer's patients are missing the gene.

In a note to investors, Friedman, Billings, Ramsey analyst David Amsellem said the results study left him unconvinced of the drug's efficacy. He said the only way to validate whether bapineuzumab was effective was to await the results of the study's next stage.

"We believe that the results are at best inconclusive, and the post hoc analysis leaves many unanswered questions ... We believe the only real validation of bapineuzumab can take place with positive Phase III results, which we will not see until mid 2010 at the earliest," he wrote.

Amsellem reiterated his "Underperform" and $13 price target on the stock.

Shares of Wyeth gained $2.08, or 4.8 percent, to close at $45.16.