PRINCETON, N.J. and TOKYO, Japan — September 18, 2026

Otsuka Pharmaceutical presented new Phase 3b results for SIMTRIYO® (centanafadine) in adults with attention-deficit/hyperactivity disorder (ADHD) and comorbid anxiety disorders at Psych Congress 2026. The randomized, double-blind study evaluated 315 adults with ADHD and generalized anxiety disorder and/or social anxiety disorder. At Week 8, centanafadine produced statistically significant improvements versus placebo in both ADHD symptoms measured by AISRS and anxiety symptoms measured by HAM-A, while additional analyses showed improvements in executive function, emotional dysregulation and clinician- and patient-rated global assessments.

Centanafadine Improves ADHD and Anxiety Measures

Centanafadine demonstrated a least-squares mean AISRS change from baseline of -18.48 compared with -12.62 for placebo at Week 8, representing a treatment difference of -5.87 points (p<0.0001). Separation from placebo was observed as early as Week 1. On the HAM-A, centanafadine produced a least-squares mean change of -12.55 compared with -10.63 for placebo, with a treatment difference of -1.92 points (p=0.0244). Additional ASRS-31 analyses showed significant improvements in total ADHD symptoms as well as inattentive, hyperactivity/impulsivity, executive function and emotional dyscontrol measures.

Phase 3b Data Show Improvements in Executive Function

The expanded dataset also demonstrated improvements in executive functioning and global disease assessments, broadening the clinical profile observed with centanafadine in this population. On the BRIEF-A Global Executive Composite, the least-squares mean change at Week 8 was -17.73 with centanafadine versus -13.46 with placebo (treatment difference -4.3; p=0.0126), with significant improvement observed as early as Week 1. Clinician- and patient-rated global assessments also favored centanafadine across ADHD and anxiety severity measures. The safety profile was generally consistent with the known profile of centanafadine, with nausea, decreased appetite and diarrhea among the most common treatment-emergent adverse events.

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Otsuka Expands SIMTRIYO Clinical Development in CNS Disorders

The Phase 3b findings expand the clinical evidence for SIMTRIYO, which is approved by the FDA for ADHD in adults and pediatric patients aged 6 years and older weighing at least 20 kg. Otsuka said the new data add evidence on the potential effects of centanafadine in adults with ADHD and comorbid anxiety disorders, a population with overlapping symptom and functional challenges. SIMTRIYO is a norepinephrine, dopamine and serotonin reuptake inhibitor (NDSRI) and CNS stimulant, and its U.S. regulatory status also includes ongoing DEA scheduling review. The Psych Congress presentation was part of 26 Otsuka-sponsored abstracts, covering centanafadine, aripiprazole and the investigational TAAR1/5-HT1A agonist ulotaront as part of the company’s broader psychiatric neuroscience research program.

Source :Otsuka press release