FDA Approves Otsuka's SIMTRIYO: First New ADHD Mechanism in Years

The FDA approved Otsuka’s SIMTRIYO (centanafadine) today, July 24, 2026, making it the first norepinephrine-dopamine-serotonin reuptake inhibitor (NDSRI) cleared for ADHD. The drug is approved for adults and pediatric patients aged 6 and older weighing at least 20 kg. It will reach pharmacies later this year after the DEA completes scheduling.

What was approved

SIMTRIYO is a once-daily extended-release capsule that blocks reuptake of all three monoamine neurotransmitters tied to attention and impulse control. Existing non-stimulants hit narrower targets. Strattera (atomoxetine) works on norepinephrine alone. Qelbree (viloxazine) is a selective norepinephrine reuptake inhibitor. Intuniv (guanfacine) targets alpha-2 adrenergic receptors. Centanafadine’s broader mechanism gives prescribers a new tool for patients who do not respond well to single-neurotransmitter drugs.

The approval covers children, adolescents, and adults. The FDA accepted the NDA for priority review in January 2026, compressing the standard 10-month review to six months.

The trial data behind it

Four registrational Phase 3 trials support the approval. In two adult studies (NCT03605680 and NCT03605836), both centanafadine dose groups showed statistically significant improvement on the Adult ADHD Investigator Symptom Rating Scale (AISRS) versus placebo, with effects visible by Week 1. In the pediatric and adolescent studies (NCT05428033 and NCT05257265), high-dose centanafadine hit statistical significance on the ADHD Rating Scale-5 (ADHD-RS-5) versus placebo, again with Week 1 onset.

Common side effects in children 6 to 12: rash and decreased appetite. In adolescents 13 to 17: decreased appetite, nausea, rash, headache, abdominal pain. In adults: headache, decreased appetite, insomnia, nausea, dry mouth, diarrhea.

The label carries two boxed warnings. The first flags higher rates of suicidal ideation and behaviors in centanafadine-treated patients aged 6 to 12 compared to placebo, requiring close monitoring of pediatric patients. The second warns of abuse, misuse, and addiction potential common to CNS stimulants.

The numbers

• Brand name: SIMTRIYO
• Generic: centanafadine
• Ticker: OTSKY (Otsuka Holdings ADR, trades OTC)
• Stock price: $34.02 (OTSKY ADR close July 23, 2026, per Polygon)
• Indication: ADHD in adults and pediatric patients 6+ weighing at least 20 kg
• Approval date: July 24, 2026
• US ADHD population: approximately 22.5 million (7 million children, 15.5 million adults, per CDC)

Otsuka Holdings is a Japanese pharmaceutical company. The ADR trades over-the-counter in the US, so volume is thin and the price reaction to FDA news may be muted compared to a Nasdaq-listed biotech. The stock closed at $34.02 on July 23, up from $33.05 the prior day.

Why this matters

ADHD is one of the largest CNS markets, with roughly 22.5 million patients in the US alone. Stimulants (Adderall, Ritalin) dominate but carry Schedule II restrictions, abuse potential, and side effects like appetite suppression and insomnia. Non-stimulants offer an alternative but have historically lower response rates. A drug that hits three neurotransmitter systems could capture patients who fall between the cracks of existing options.

Otsuka is not a major player in US CNS, so commercial execution will determine whether SIMTRIYO becomes a meaningful product or stays niche. The drug enters a crowded market dominated by generic stimulants and faces competition from Qelbree, the newest non-stimulant entrant. The boxed warning on suicidal ideation in children 6 to 12 may also constrain prescribing in that age group.

What to watch next

The DEA scheduling decision will determine when SIMTRIYO actually launches. Otsuka said availability is expected later this year. Watch for the full prescribing information and any label restrictions that could affect uptake. Otsuka also recently completed a Phase 3b study in adults with ADHD and comorbid anxiety showing statistically significant improvements, which could support a future label expansion.

Sources: Otsuka FDA approval announcement, FDA Novel Drug Approvals 2026, Otsuka Phase 3 post-hoc analyses. See our guide on how to read a clinical trial press release.