Shares of Vanda Pharmaceuticals
How could that be? Investors only care about how much of the drug Vanda can sell, and study results that may be good enough for continued clinical testing and possible marketing approval don't guarantee a commercially successful drug.
What has discouraged investors is that while Vanda's potential insomnia treatment, tasimelteon, met its primary goal of improving patients' ability to fall asleep (called sleep onset), it produced mixed results at best for some of its secondary goals that had to do with whether the drug improved patients' ability to stay asleep (called sleep maintenance).
Tasimelteon still could reach the market even if Vanda only makes sleep-onset claims on the drug's label, but improving insomniacs' sleep maintenance is where the money is, and what has made compounds like Sanofi-Aventis'
Vanda has other development problems not specific to tasimelteon, but which could affect all insomnia drugs in development going forward. Last year, the Food and Drug Administration handed a harsh rebuke to Neurocrine Biosciences