Avadel Pharmaceuticals plc (AVDL)

Avadel Pharmaceuticals plc is an Irish specialty pharmaceutical company that was formerly Flamel Technologies, a French drug delivery company founded in 1990 in Lyon. Flamel's American depositary shares were listed on Nasdaq in 1996. In 2016 the company redomiciled to Ireland, and in January 2017 it adopted the Avadel name. Its headquarters were in Dublin, with operations in the United States.

In its earlier years, the business depended on drug delivery technologies and on a portfolio of hospital products. Over time Avadel sold or wound down much of that portfolio to focus on one neurology program, an extended-release formulation of sodium oxybate for narcolepsy. The company's strategy changed from technology licensing to developing and commercializing its own differentiated product.

That product, Lumryz, is a once-nightly formulation of sodium oxybate for treating cataplexy or excessive daytime sleepiness in people with narcolepsy. The U.S. Food and Drug Administration approved it in 2023, and Avadel launched it commercially. Because other sodium oxybate products require two doses during the night, the once-nightly dosing was the central point of differentiation.

Avadel's path was marked by legal disputes with a competitor over patents and regulatory exclusivity relating to sodium oxybate products. The company also pursued additional indications for Lumryz, including a program in idiopathic hypersomnia. Its shares traded on the Nasdaq Global Market under the symbol AVDL.

In October 2025, Alkermes plc, another Irish pharmaceutical company, announced an agreement to acquire Avadel in a transaction aimed at building a sleep medicine franchise. Avadel later received a competing proposal from H. Lundbeck A/S, and Alkermes then increased its offer. The final terms were $21.00 in cash per share plus one non-transferable contingent value right entitling the holder to a potential additional $1.50 in cash upon a specified milestone.

The acquisition was carried out through a court-sanctioned scheme of arrangement under the Irish Companies Act 2014. The High Court of Ireland sanctioned the scheme on February 10, 2026, and it became effective on February 12, 2026. At Avadel's request, Nasdaq halted trading at 7:50 p.m. New York time on February 11, 2026, and a Form 25 was filed to delist the shares. Alkermes and Avadel then planned to file a Form 15 to deregister the shares.

The acquisition gave Alkermes an established commercial product in sleep medicine alongside its own pipeline, including its orexin-targeting research programs. The contingent value right allows former Avadel holders to receive a further payment only if the specified milestone is reached before the CVR expires, and it is not a traded security. Alkermes, which is also incorporated in Ireland, continues to trade on Nasdaq under the symbol ALKS.