What happened Shares of Avadel Pharmaceuticals (NASDAQ: AVDL) are down 14% as of 1:29 p.m. EDT today after the Food and Drug Administration said it would need more time than originally thought to review FT218 -- Avadel's candidate to treat narcolepsy. So what After accepting a company's approval filing, the FDA provides applicants with a date known as the Prescription Drug User Fee Amendments date -- or PDUFA date. It's intended to give drugmakers insight into the review timeline. Image source: Getty Images. In some instances -- like that of Avadel's FT218 -- the agency misses its target. In this case the PDUFA date was Oct. 15. Although no new date has been given, the FDA did inform the company that no action is likely to be taken in October. Investors clearly weren't expecting the delay. The stock had been up more than 50% in the past three months prior to today's announcement. Now what To date there have been no red flags. The double-blind, placebo-controlled phase 3 clinical trial for FT218 was completed in March 2020, just as the pandemic took hold in the U.S. The treatment proved effective and safe at all three doses administered. The company still hasn't been notified of any deficiencies in its application, and the FDA has said it will provide a new date as soon as possible. There may also be some pressure from patients for the agency to act quickly. According to the company, there are about 170,000 people with narcolepsy in the U.S. Avadel's once-at-bedtime treatment may actually outperform an already approved twice-nightly formulation. In addition, eligible patients have ranked the once-per-night dosing as the most important factor in choosing a treatment. That market opportunity should give shareholders some patience as they wait for the FDA's new action date. 10 stocks we like better than Avadel Pharmaceuticals plcWhen our award-winning analyst team has a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* They just revealed what they believe are the ten best stocks for investors to buy right now... and Avadel Pharmaceuticals plc wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of September 17, 2021 Jason Hawthorne has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.Source