Richard Pascoe, chief executive of Somaxon Pharmaceuticals (SOMX-$1.10), expressed confidence that the resubmitted New Drug Application of Silenor (doxepin) for insomnia in adults will address the FDA’s concerns about the drug's sleep maintenance efficacy and cardiac safety profile (risk of ventricular arrhythmias). Irrespective of a favorable approval, the commercial success of Silenor is far from a certainty.
It will take at least six-months for the FDA to complete its review—and the marketing window for Silenor is closing quickly, with the in-licensed patent for the treatment of chronic insomnia (when the inability to fall asleep last for more than three weeks) scheduled to expire in March 2013. In addition, although the company claims that Silenor’s selective histamine H-1 blockade – and lack of specificity for re-uptake at other central nervous system target sites – makes the drug a good candidate for insomnia, it is unlikely that mechanism of action alone will be enough to convince physicians to switch from better established sleep hypnotics, which include Lunesta (eszopiclone), Ambien CR (and its generic zolpidem), and Restoril (and its generic temazepam).
Somaxon is running out of cash, and is expected to announce a highly dilutive capital offering by the end of July (likely stock-warrant units). Management has yet to formalize a strategic partnership with a pharmaceutical company that already has established access to the highest prescribing physicians of insomnia treatments, too. The longer it takes the company to announce a strategic deal, the less income it is likely to keep in a royalty-sharing arrangement.
It’s a common myth that your sleep quality decreases as you age. Existing Somaxon shareholders, however, have plenty of worries to keep them up at night.
Editor David J Phillips does not hold a financial interest in any stocks mentioned in this article. The 10Q Detective has a Full Disclosure Policy.