NDA Review for FT218 in Narcolepsy Still Ongoing, FDA Announces

The new drug application (NDA) for Avadel Pharmaceutical’s investigational agent FT218, a once-nightly sodium oxybate formulation for treatment of excessive daytime sleepiness and cataplexy in adults with narcolepsy, is still under review, the FDA announced today.

The NDA was originally accepted by the FDA in February 2021, setting a Prescription Drug Use Fee Act action date of October 15, 2021. Application was based on positive data from the phase 3 REST-ON study (NCT02720744), which was held under a special protocol assessment agreement with the FDA.

“We have addressed all questions received to date and remain confident that the package we have submitted satisfies all of the FDA’s requests. We have not been informed of any deficiencies in our application and remain fully committed to work closely with the FDA for the duration of its review of our NDA for FT218,” Greg Divis, CEO, Avadel, said in a statement.¹ “Once-at-bedtime FT218 has the potential to truly impact the way people with narcolepsy are able to live their lives and we are dedicated to making this important therapy available to patients as quickly as possible.”

The REST-ON study included a total of 222 patients with narcolepsy, all of whom were 16 years or older. Patients were randomized 1:1 to receive uptitration doses of 4.5 g, 6 g, 7.5 g, and 9 g of FT218 or placebo over the course of a 3-week screening period, a 13-week treatment period, and a 1-week follow-up period.²

The study met all 3 of its primary end points, which were change from baseline in mean sleep latency on the Maintenance of Wakefulness test, Clinical Global Impression Improvement, and weekly cataplexy attacked within the 6-, 7.5-, and 9-g groups. Investigators, led by Clete A. Kushida, MD, PhD, director, Stanford Center for Human Sleep Research, noted that randomization was stratified by narcolepsy type 1 or type 2.

Compared to placebo, treatment with FT218 resulted in a significantly greater increase in sleep latency at week 3 for the 6-g dose group (8.1 vs 3.1 min, respectively; least squares mean change from baseline [LSMD], 4.98 [95% CI, 2.90-7.05]; P <.001); at week 8 for the 7.5-g dose group (9.6 vs 3.3 min, respectively; LSMD, 6.21 [95% CI, 3.84-8.58]; P <.001); and at week 13 for the 9-g dose group compared with placebo (10.8 vs 4.7 min, respectively; LSMD, 6.13 [95% CI, 3.52-8.75]; P <.001).²

REFERENCE

1. Avadel Pharmaceuticals announces ongoing FDA review of NDA for FT218 for patients with narcolepsy. News release. Avadel Pharmaceuticals. October 15, 2021. Accessed October 15, 2021. https://www.globenewswire.com/news-release/2021/10/15/2315210/0/en/Avadel-Pharmaceuticals-Announces-Ongoing-FDA-Review-of-NDA-for-FT218-for-Patients-with-Narcolepsy.html
2. 1. Kushida CA, Shapiro CM, Roth T, et al. Once-nightly sodium oxybate (FT218) demonstrated improvements of symptoms in a phase 3 randomized clinical trial in patients with narcolepsy. SLEEP. Published online August 6, 2021. doi: 10.1093/sleep/zsab200.