Lundbeck shares have taken a bashing after the drugmaker and partner Takeda Pharmaceutical Co announced disappointing news from late-stages trials of their new antidepressant.

The Denmark-headquartered firm published headline results from the first three trials in its Phase III development programme of Lu AA21004 in major depressive disorder. Two of the studies revealed that at lower dosages, 2.5mg and 5mg, the drug did not reach significance across studies when compared with placebo.

A third trial demonstrated mixed results, Lundbeck noted, with the 2.5mg dose not having any significant effect and while the 5mg and 10mg doses showed separation from placebo, but not in all analyses.
In all of these trials, Lu AA21004 was well tolerated “and confirmed the previously observed favourable safety profile” the company added.

As a result, “the most appropriate dose of Lu AA21004 needs to be established” and Lundbeck says the findings “suggest that a higher dose may be more efficacious”. However this scenario has forced the postponement of a submission of a New Drug Application in the US by 18-24 months.

This means that Lundbeck and Takeda will not probably not file Lu AA21004, which is also in Phase III development for generalised anxiety disorder, before the end of 2011. This is a blow as the Copenhagen-based company’s biggest earner, the antidepressant Cipralex/Lexapro (escitalopram) will go off-patent in 2012 through 2014.

Despite the setback, Lundbeck is optimistic and said Lu AA21004 has the potential to show “a high efficacy profile with a strong anxiolytic component and a favourable side effect profile”, specifically having shown no/a low impact on sexual side effects. Investors seem to a bit more concerned, however, and the company’s shares ended the day down 16.5% at 100.25 kroner.