As this story was being published, Vanda announced a follow-on stock offering of 4 million shares.
WASHINGTON, DC (
) -- In June, I uncovered a long list of
deficiencies and shortcuts
(VNDA - Get Report)
in the development of tasimelteon, a melatonin receptor agonist, for the treatment of a rare sleep-pattern disorder that affects blind people.
My conclusion: The odds of FDA approving Vanda's tasimelteon for non-24 sleep-wake disorder were exceedingly small.
I based my last analysis primarily on the larger of two phase III studies Vanda conducted on tasimelteon -- the so-called "SET" study. Vanda's second phase III study -- known as "RESET -- is equally troublesome.
Let's take a closer look.
RESET was a randomized withdrawal study, meaning all patients diagnosed with non-24 entered first into a run-in stage in which they were treated with daily tasimelteon for three months. After three months of receiving tasimelteon, patients were randomized to one of two groups: 1) continued tasimelteon treatment for two months; or 2) a switch to placebo for two months.
At the end of the two-month withdrawal phase, patients were measured for response, defined as maintenance of entrainment, or adherence, to a normal 24-hour circadian rhythm.
Vanda declared victory in the RESET study, claiming 90 percent of tasimelteon-treated patients maintained entrainment of their circadian rhythm after two months compared to 20 percent of placebo-treated patients. The difference in entrainment maintenance was statistically significant.
Here's a chart describing the RESET primary endpoint, taken from a poster presented at the Endocrine Society (ENDO) meeting in June.
Was the tasimelteon benefit clinically meaningful or relevant at all for getting the drug approved? I don't believe so.
Vanda chose to measure maintenance of entrainment at a fixed and arbitrary point in time, defined in RESET as two months. A non-24 patient was deemed a responder in RESET if he/she maintained entrainment at two months.
Of the 10 patients treated with tasimelteon, 9 maintained entrainment after two months. Ten patients were treated with placebo but only two maintained entrainment for two months. [I'll address the issue of only having 20 patients to analyze in what is supposed to a pivotal, phase III study later.]
Why is this claimed success irrelevant? Because it doesn't matter if non-24 patients maintain entrainment for two months if they continue to suffer from sleep problems.