Transcept receives CRL from FDA for low-dose zolpidem tartrate formulation

FDA has issued a Complete Response Letter (CRL) for Intermezzo (zolpidem tartrate sublingual tablet, Transcept Pharmaceuticals).

Zolpidem tartrate is a sublingual low-dose formulation whose active agent is most commonly prescribed in the United States for the treatment of insomnia, the manufacturer said. This formulation uses approximately one-quarter to one-third of the dose of active drug contained in currently marketed zolpidem-based sleep aids, and it is designed to promote rapid sublingual absorption. The drug had the potential to be the first prescription sleep aid specifically approved for use in the middle of the night at the time a patient wakes and has difficulty returning to sleep.

The company originally submitted its new drug application (NDA) for Intermezzo in September 2008 subsequently receiving a CRL in October 2009 in which FDA cited concerns about dosing errors with less than 4 hours of bedtime remaining and inadvertent re-dosing in a single night. Transcept addressed those concerns, resubmitting its NDA in January 2011.

In the CRL received this month by Transcept, FDA noted that Transcept adequately demonstrated Intermezzo’s effectiveness for use as needed in the treatment of insomnia when a middle-of-the-night awakening is followed by difficulty returning to sleep; however, FDA was not satisfied with the safety data in the Intermezzo NDA. In addition, the cited concerns that patients with higher zolpidem blood levels from Intermezzo could be at risk of unacceptable next-day impairment, and hypothesized that these patients may belong to distinct and identifiable demographic groups.

As a possible path forward, FDA suggested that Transcept further investigate whether body weight and demographic factors contribute to a difference in elevated blood levels the morning after taking Intermezzo, develop strategies to decrease next-morning zolpidem levels, and then demonstrate that next-morning blood levels do not present an unacceptable risk of next-day impairment, which may include the need for an additional driving study, the company reported.

Transcept plans to discuss with FDA the potential paths forward. Meanwhile, following FDA notification, the company announced that it plans to eliminate approximately 45% of its workforce to reduce operating expenses.

"Our staffing needs have changed after the recent news from FDA on the regulatory status of Intermezzo,” said Glenn A. Oclassen, president and CEO commented in a follow-up company statement. “We are therefore phasing out certain positions that are non-essential to our plan to pursue potential paths forward with the FDA on the Intermezzo NDA, and to continue development of our TO-2061 program. This cost containment step is consistent with our long-standing principle of conservative cash management."