Salmon has provided (in comments, below) an excellent new piece of the asenapine (now branded as Saphris®, by legacy Schering-Plough/New Merck) puzzle. On March 1, 2010, in Munich, Germany, researchers hired by Merck presented some new study results, from an asenapine study designed to measure efficacy at a therapy duration of 12 weeks.
Oddly, the study's PI (or "principal investigator") reported out the data from week 3 (even though the study actually ran for 52 weeks), apparently. Do go read it all (at the link), but here is an interesting snippet:
. . . .Joseph Calabrese, MD, PhD, Mood Disorders Program, Case Western University School of Medicine, Cleveland, Ohio, and colleagues determined the efficacy of asenapine co-treatment with lithium or valproate in a 12-week primary study and a blinded extension study that followed for 40 weeks.
The primary-study endpoint was to evaluate the efficacy, safety, and tolerability of adjunctive asenapine for acute manic or mixed episodes in patients with bipolar disorder who incompletely responded to lithium or valproate monotherapy. The extension study had the same endpoints in addition to determining the maintenance of efficacy of adjunctive asenapine treatment.
The primary study was a randomised, double-blind, placebo-controlled trial wherein patients who had incompletely responded to treatment with a mood stabiliser received sublingual flexible-dose adjunctive asenapine 5 or 10 mg BID (n = 155) or placebo (n = 163). The 40-week blinded extension included 38 patients from the asenapine group and 33 from the placebo group. . . .
The incidence of treatment-emergent adverse events with asenapine and placebo was 73% and 69% in the core study and 78% and 69% in the extension. . . .
Is Salmon right, here (as he so often is) -- is this the use of the classic early effect magnification version of "cherry-picking" a study's results?
. . . .Plus, at 52 weeks PLACEBO BEAT ASENAPINE.
Now of course the author could have it wrong. Initial 3 week evaluations are more common with acute mania with extensions to 12 and 52 weeks. But if the message is supposed to be that asenapine is useful for extension beyond three weeks then I don't see it. Besides I've discussed other reports of extension studies here before and they also had major problems.
All in all so far everything I've seen so far does argues against any extended use beyond three weeks. . . .
I'll do some more digging -- but I doubt the study is registered at ClinicalTrials.gov. We'll see. Great find, Salmon!