Alkermes plc announced on September 21, 2026, that it has completed a phase 1 proof-of-concept study evaluating ALKS 7290, an investigational orexin 2 receptor agonist, for the treatment of attention-deficit hyperactivity disorder (ADHD). The study, which included 88 healthy volunteers and 50 adults with ADHD, evaluated the safety, tolerability, pharmacokinetics, and pharmacodynamics of the drug.
The primary objective of the phase 1b portion of the study was to assess safety, which was generally well tolerated at all doses tested. In the adult ADHD cohort, ALKS 7290 demonstrated dose-dependent, clinically meaningful improvements on exploratory endpoints. These included the Adult ADHD Investigator Symptom Rating Scale (AISRS) and the Clinical Global Impression-Severity Scale (CGI-S). At day 14, participants receiving the 20 mg dose showed a median reduction of 14.0 points on the AISRS, while those receiving the 50 mg dose showed a reduction of 19.0 points. Similarly, CGI-S scores improved by 1.0 point in the 20 mg group and 2.0 points in the 50 mg group.
Regarding safety, the company reported that no serious treatment-emergent adverse events occurred. The most common adverse events included insomnia, pollakiuria, dizziness, change in sustained attention, micturition urgency, and constipation. In healthy volunteers, the maximum tolerated dose was not reached during the study.
Alkermes stated that these results support the dose range selected for an ongoing phase 2 study. This phase 2 trial, currently enrolling participants (NCT07755410), is expected to enroll approximately 312 adults with ADHD. The study will evaluate the primary endpoint of change from baseline in AISRS total score at week four compared to placebo. Data from this phase 2 study is expected in 2027.
