Exhibit 99.1 Avadel Pharmaceuticals Provides Corporate Update and Reports First Quarter 2024 Financial Results -- Generated $27.2 million in net revenue from sales of LUMRYZ™ -- -- Through March 31, greater than 2,800 patients enrolled in Avadel’s RYZUP patient support services and more than 1,700 patients initiated therapy -- -- Pursuing expansion opportunities for LUMRYZ with sNDA in pediatric narcolepsy; on track to enroll first patient in a Phase 3 pivotal idiopathic hypersomnia trial in the second half ...