Exhibit 99.1 HARMONY BIOSCIENCES REPORTS STRONG FIRST QUARTER FINANCIAL RESULTS AND ACCELERATION OF ITS GROWTH STRATEGY; ADVANCES PITOLISANT FRANCHISE TO EXTEND REVENUE POTENTIAL BEYOND 2040; STRENGHTENS SLEEP/WAKE LEADERSHIP AND DIVERSIFIES INTO RARE EPILEPSY WAKIX® (pitolisant) Net Revenue of $154.6 Million for First Quarter 2024; ~30% Growth Year-over-Year Supplemental New Drug Application for Pitolisant in Idiopathic Hypersomnia Planned for Second Half 2024 On Track Toward Pediatric Exclusivity to Exten ...