Transcept Pharmaceuticals has finally secured the backing of regulators in the USA for its insomnia drug Intermezzo.
The US Food and Drug Administration has approved Intermezzo (zolpidem) for use as needed to treat insomnia characterised by middle-of-the-night waking followed by difficulty returning to sleep. This is the first time the agency has approved a drug for this condition.
The treatment is a low dose of zolpidem, the active ingredient in Sanofi’s sleeping bill Ambien, which was first approved in 1992 in the USA. The recommended and maximum dose of Intermezzo is 3.5 mg for men and half that for women, as the latter clear zolpidem from the body at a lower rate.
The news is a major boost for Transcept seeing as how in July, the FDA issued another complete response letter, (the original rejection came in October 2009). The agency said that a study conducted to assess the effect of Intermezzo on subjects' next-day driving ability was still not sufficient to grant approval.
Approval at third time of asking
Transcept duly refiled the NDA at the end of September and reduced the recommended Intermezzo dose for women to 1.75mg. Its proposal also included instructions stating that the drug should only be taken if patients have at least five hours of bedtime remaining, and they should not drive for at least an hour after arising and until five hours after taking the sublingual tablet.
Robert Temple, deputy centre director for clinical science in the FDA’s Center for Drug Evaluation and Research, said that “with this lower dose there is less risk of a person having too much drug in the body upon waking, which can cause dangerous drowsiness and impair driving.”
Intermezzo was studied in two trials, involving more than 370 patients, which showed that those taking the drug had a shorter time to fall back asleep after waking compared to people on placebo. The most commonly reported adverse reactions were headache, nausea and fatigue.
The FDA also noted that Intermezzo is a federally controlled substance because it can be abused or lead to dependence. Also Transcept has agreed to post-marketing commitments including a study of patient compliance and paediatric use assessment. Intermezzo will be sold by partner Purdue Pharma.
The rejection in July was followed by Transcept announcing plans to reduce operating expenses by eliminating 45% of its workforce.