Alkermes plc reported topline results from a Phase 1 proof-of-concept study of ALKS 7290, an investigational oral orexin 2 receptor agonist for adults with attention-deficit hyperactivity disorder (ADHD). The study included 88 healthy volunteers and 50 adults with ADHD and provided the first clinical evidence of an orexin receptor agonist treating ADHD symptoms. In the Phase 1b segment, adults received daily split doses of 20 mg or 50 mg of ALKS 7290, or placebo, for 14 days after a two-week washout of prior medications. At day 14, median reductions on the Adult ADHD Investigator Symptom Rating Scale were 14.0 points for the 20 mg group and 19.0 points for the 50 mg group, with improvements emerging as early as day 6 across inattentive and hyperactivity measures. Clinical Global Impression-Severity scores also improved, while EEG biomarkers and cognitive assessments showed effects in working memory, attention, processing speed and information processing. ALKS 7290 was generally well tolerated, with no serious treatment-emergent adverse events and no discontinuations among participants receiving the drug. Alkermes is enrolling approximately 312 adults in a four-week Phase 2 study, and the first participant was dosed in September 2026. Shares were up 1.27% at $43.95 at the time of publication, according to Benzinga Pro data.