Exhibit 99.1 Supernus Announces First Quarter 2024 Financial Results • Net sales of Qelbree® increased 75% to $45.1 million compared to first quarter 2023. • Total revenues were$143.6 million. Total revenues excluding Trokendi XR® and Oxtellar XR® net product sales (non- GAAP)(1) increased 12% to $100.7 million compared to first quarter 2023. • Operating loss was$(3.2) million. Adjusted operating earnings (non-GAAP)(1) was $22.3 million. • Reiterates full year 2024 financial guidance, including total reve ...