Transcept Gets CRL From FDA For Resubmitted NDA For Insomnia Drug Intermezzo

Transcept Pharmaceuticals, Inc. (TSPT) late Thursday said it has received a Complete Response Letter from the U.S. Food and Drug Administration for the resubmitted New Drug Application for Intermezzo, a new drug to help insomnia sufferers return to sleep when they wake up in the middle of the night.

Intermezzo, or zolpidem tartrate sublingual tablet, is a sublingual low dose formulation of zolpidem, the same as that found in well known prescription medication Ambien and its generic version. The Richmond, California-based company resubmitted its Intermezzo NDA, addressing the FDA concerns, in January 2011.

In the Complete Response Letter, the FDA confirmed that Intermezzo is efficacious for use as needed in the treatment of insomnia when a middle-of-the-night awakening is followed by difficulty returning to sleep. However, the regulatory agency raised concerns about how safely Intermezzo can be used based on the information in the New Drug Application.

Further, the FDA said it is concerned that those patients with higher zolpidem blood levels from Intermezzo could be at risk of unacceptable next-day impairment. In addition, the FDA hypothesized that such patients may belong to distinct and identifiable demographic groups.

If approved, Intermezzo would have been the first sleep aid for use in the middle of the night at the time of awakening. The currently approved sleep aids like Ambien, Ambien CR, Lunesta, Restoril, Rozerem, Sonata, Desyrel and Silenor, are indicated for bedtime use only. The potential market of sleep aids to treat middle of the night awakenings is estimated to be worth $1.9 billion to $3.4 billion.

Transcept initially filed its New Drug Application with the FDA seeking approval for Intermezzo in September 2008. The drug failed to clear the regulatory muster then as the FDA, which reviewed the Intermezzo NDA, issued a complete response letter in October 2009. The FDA sought additional data with particular reference to Intermezzo's impact on next day driving ability.

Following Intermezzo's rejection again, Transcept said it plans to meet with the FDA to discuss the potential paths forward.

TSPT shares closed Thursday's regular trading at $4.73 on the Nasdaq.

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