Wednesday, December 06, 2006

Lexapro Beats Cymbalta

But was the full story really told? In a study released today by Forest Labs, its product Lexapro bested Lilly's Cymbalta in a head to head trial.

"Sixty-eight percent of patients who received Lexapro reached the improvement goal [50% or greater reduction in Montgomery Asberg Depression Rating Scale scores] compared to 52 percent who responded to treatment with Cymbalta. The result, which included patients who did not complete the full eight weeks of treatment, was deemed statistically significant, Kahn [study author] said.

In addition, 44 percent of the Lexapro patients experienced near total disappearance of depression symptoms compared with a 38-percent remission rate in the Cymbalta group, which was not statistically significant. Remission was defined as a score of 10 or less on the MADRS depression scale. "

That's all fine and good. I'd be interested to see if the average level of improvement was different between the two groups, since that was not discussed in the brief Reuters writeup. You can bet that when this trial gets published, Forest will purchase reprints aplenty. I can't wait to see the actual study and examine its results firsthand.

Research as indicated either a very small or no advantage for one group of antidepressants over another. Wyeth funded some trials which found, on average, a very small (likely clinically negligible) advantage for Effexor over other antidepressants, but do you think that they published all studies that failed to find results favoring their product? The reason I make this point about equal efficacy is that I am suspicious any time an antidepressant trial finds one med did much better than another, as such a result is bucking a very consistent finding. So in the current trial, I’m guessing that the dose of Cymbalta was too low, that the mean difference was not significant, or that this is was a fluke occurrence. When the study data are available (they are currently not in Forest's clinical trial database), I'll let you know what I see. I would not be surprised if the MADRS 50% criterion was the only measure showing a difference in favor of Lexapro and that Forest is thus running as far as they can with that particular finding, although other measures failed to back it. Maybe I'm wrong; we'll see.

Don't take this as my flacking for Cymbalta. I'm far from impressed with it, as you can see here. To reiterate, I just find it interesting when a trial shows a difference between compunds when a much larger body of literature has suggested that there really is no difference in efficacy between types of antidepressants (and little difference between medication and placebo). Perhaps I should not make such a big deal about this – after all, this whole issue could just be a matter of sharks eating sharks.

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