Wednesday, September 8, 2010

FDA Follows EMEA: Clearing New Indication For Asenapine

Overnight, the United States FDA approved Asenapine for two new indications. Asenapine is Merck's atypical antipsychotic (inherited from legacy Schering-Plough), and branded as Saphris® here, and as Sycrest® in the EU. This action follows a similar expanded indication approval last week, in Europe:

. . . .The drug was first approved in August 2009 for treating acute schizophrenia in adults and acute mania or manic-depressive behavior in adults with bipolar disorder. Merck says the FDA now has approved Saphris for continuing treatment of schizophrenia and for treating acute mania or manic-depressive behavior in adult bipolar patients along with lithium, a mood-stabilizing drug often used to treat mania, or the anti-seizure drug valproate. Saphris carries the FDA's strongest caution, a black box warning, that it nearly doubles risk of death in elderly patients with dementia.

Rival drugs include Johnson & Johnson's Risperdal®, Eli Lilly & Co.'s Zyprexa®, AstraZeneca PLC's Seroquel®, Pfizer Inc.'s Geodon® and Bristol-Myers Squibb Co.'s Abilify®. . . .

As Salmon has cogently pointed out -- it will likely rremain an anemic seller -- for a host of reasons, including side-effects.


Anonymous said...

Now isn't that convenient. Approval for long term treatment at the same time as approval in the EU.

I'm getting a sense of Deja Vu. Didn't we have reporting of long term trials (Dec 2008) on the cusp of the approvable letter from the FDA. As I recall those long term efficacy studies were inherently biased as they selected out patients known to respond as well as had such a long run in that anyone who actually went on Saphris had a very low chance of relapsing as they were likely exceptionally sensitive to treatment.

As for BP when you look at the labeling for other antipsychotics on long term efficacy you see only a few days longer efficacy for patients on drug as compared to placebo so the efficacy is really being driven by only 1 or 2 patients. But as we know if you have large enough numbers you can make anything statistically significant.

Since studies are typically designed similar to ones used to approve other drugs under similar conditions I doubt that the study would have been designed in such a way to show that combination with a specific agent is actually meaningfully better than that agent alone and that each agent contributes to efficacy when used in combination. (Which is the legal standard).

Another caveat is that these studies are typically not very useful for evaluating long term toxicity. (Too small, too short, not looked for.) Yet they can provide a false sense of security.


Anonymous said...

Interesting comment from American Human Research Protection. Merck has a cutoff of $50 million per quarter or $200 million per year for reporting individual sales. Consequently since no individual sales have been reported for Saphris in the first 3 quarters of sales then the figures are likely below this.