The US Food and Drug Administration (FDA) declined approval of Cephalon’s new drug application for NUVIGIL for the treatment of excessive sleepiness associated with jet lag disorder, calling into question data the company submitted when seeking approval.

“Although we reached statistical significance on both primary endpoints, the Complete Response letter raised questions regarding the robustness of the PGI-S data,” said Dr Lesley Russell, Cephalon’s chief medical officer. “We have already reviewed this issue with the FDA and will be scheduling a meeting with the Agency in the near future to discuss it further.”

In studying a treatment option to improve wakefulness associated with jet lag disorder, Cephalon worked closely with the FDA to design a special protocol assessment (SPA) that would evaluate the experience of a typical eastbound airline traveler.

In the evaluation, clinical efficacy was examined using two primary endpoints: an objective assessment—the Multiple Sleep Latency Test (MSLT); and a subjective assessment—the Patient Global Impression of Severity (PGI-S). Patients taking NUVIGIL (150 mg/day) showed a statistically significant improvement over placebo as measured by the MSLT (P <0.0001) and the PGI-S (P = 0.044), a statement from the company said. The most common adverse events associated with NUVIGIL treatment (5% or greater) were headache, nausea, insomnia, diarrhea and palpitations. There were no reports of serious rash observed in the trial participants, and no new safety signals were observed in the clinical trial.

Cephalon’s shares fell as a result of the FDA’s response.