A New Frontier in ADHD Pharmacotherapy: Centanafadine (SIMTRIYO®)

The therapeutic landscape for attention-deficit/hyperactivity disorder (ADHD) has reached an important milestone. Following the New Drug Application (NDA) submission by Otsuka Pharmaceutical in November 2025 and a Priority Review designation in January 2026, the US Food and Drug Administration (FDA) approved centanafadine (brand name SIMTRIYO®) on July 24, 2026. Indicated for the treatment of ADHD in adults and pediatric patients aged 6 years and older weighing over 20 kg, centanafadine represents the first approved molecule in a novel pharmacologic class: norepinephrine, dopamine, and serotonin reuptake inhibitors (NDSRIs).

A Landmark Milestone in ADHD Therapeutics

ADHD is a complex neurodevelopmental disorder that affects approximately 5.6% of adolescents globally and frequently persists into adulthood, impacting over 50% of diagnosed youth throughout their lives. While traditional psychostimulants and selective nonstimulants have long served as primary pharmacological options, clinical gaps persist regarding tolerability, adherence, loss of efficacy, and risk of misuse or diversion.

The approval of centanafadine is supported by a comprehensive Phase 3 clinical development program encompassing four pivotal trials in children, adolescents, and adults.

Why It Matters

Limitations of Existing ADHD Pharmacotherapies

To understand the clinical importance of centanafadine, healthcare providers must evaluate the current challenges associated with standard ADHD medications:

• Psychostimulants (Methylphenidate and Amphetamine derivatives): While highly effective for core symptoms, stimulants primarily target dopamine and norepinephrine transporters. However, their clinical utility can be constrained by appetite suppression, adverse cardiovascular events, sleep disturbances, potential for misuse or diversion, and patient-reported tolerability issues, such as adolescents feeling like they “stopped feeling like themselves”.
• Selective Nonstimulants (Atomoxetine, Guanfacine, Viloxazine XR, Clonidine): Nonstimulants lack abuse potential and provide continuous coverage. However, they act primarily through noradrenergic mechanisms alone and are generally recognized as producing lower effect sizes on core ADHD symptoms compared to stimulants.

The Science of Triple Reuptake Inhibition

Centanafadine is a novel extended-release central nervous system agent that inhibits the reuptake of norepinephrine, dopamine, and serotonin. While dopamine and norepinephrine pathways are well-established key drivers of executive function and impulse regulation, emerging neurobiological research emphasizes the interconnected role of the serotonergic system in ADHD pathophysiology:

• Serotonergic Modulation: Serotonin (5-HT) interacts directly with dopaminergic and noradrenergic networks. It regulates key neuropsychological domains relevant to ADHD, including attention, impulsivity, motor hyperactivity, emotional regulation, executive dysfunction, mood, and sleep.
• Broad Functional Benefits: By simultaneously modulating all three monoamine systems, centanafadine provides comprehensive coverage across core symptoms and associated executive dysfunctions.

Addressing Abuse Potential and Emotional Dysregulation

Two major clinical advantages set centanafadine apart:

1. Low Abuse and Dependence Potential: Despite enhancing synaptic dopamine levels, pre-clinical and clinical evaluations indicate that centanafadine possesses a low potential for dependence and abuse, distinguishing it from schedule II stimulants.
2. Efficacy on Executive Function and Emotional Dysregulation: Post hoc analyses of Phase 3 data presented at the 2026 American Society of Clinical Psychopharmacology (ASCP) Annual Meeting demonstrated that centanafadine significantly improves patient-reported executive functioning, including time management, working memory, task initiation/completion, and planning/prioritization, as well as emotional dysregulation.

Who It Affects

Target Populations and Efficacy Across the Lifespan

Centanafadine is approved for adults and pediatric patients aged 6 years and older weighing more than 20 kg. Its efficacy and safety profile were evaluated across four pivotal Phase 3 trials spanning children (ages 6–12), adolescents (ages 13–17), and adults (ages 18–55).

Deep Dive: The Adolescent Phase 3 Clinical Trial

A randomized, double-blind, placebo-controlled trial published in the Journal of the American Academy of Child & Adolescent Psychiatry (JAACAP) evaluated once-daily centanafadine in adolescents aged 13–17 with a primary diagnosis of ADHD.

Study Design and Baseline Demographics

• Participants: 459 adolescents were randomized 1:1:1 to receive centanafadine 164.4 mg (n=155), centanafadine 328.8 mg (n=155), or placebo (n=149) once daily for 6 weeks without initial dose titration.
• Dosing Logic: Doses were calculated to achieve drug exposures equivalent to the 200 mg and 400 mg total daily doses validated in adult Phase 3 trials.
• Baseline Severity: Participants exhibited moderate-to-severe symptoms at baseline, with a mean ADHD Rating Scale, version 5 (ADHD-RS-5) total raw score of 37.5 (SD 6.1) and a mean Clinical Global Impression of Severity (CGI-S-ADHD) score of 4.5 (SD 0.6).
• Completion Rate: 80.8% (371/459) of participants completed the 6-week study.

Primary Efficacy Endpoint Results

The primary efficacy endpoint was the change from baseline in the ADHD-RS-5 symptoms total raw score at week 6:

• Centanafadine 328.8 mg: Achieved a statistically significant improvement compared to placebo (-18.50 \[SE 0.93\] vs -14.15 \[SE 0.93\]; p = .0006), representing a Cohen’s d effect size of -0.40.
• Centanafadine 164.4 mg: Demonstrated numerical improvement over placebo (-15.5 vs -14.2; p = .3016), but did not reach statistical significance on the primary endpoint.
• Onset of Action: The 328.8 mg dose demonstrated statistically significant separation from placebo as early as Week 1 (p = .001), the first post-baseline assessment, with therapeutic benefits maintained throughout the 6-week trial.

Key Secondary Endpoints and Subscale Outcomes (328.8 mg Arm)

At Week 6, adolescents receiving centanafadine 328.8 mg showed significant improvements across several clinician- and parent-rated domains:

• Global Severity (CGI-S-ADHD): Significant reduction vs placebo (-1.42 vs -1.06; p = .0038).
• Conners 3-Parent Short Content Scales:
• Inattention T-score: -14.4 vs -8.1 placebo (p < .0001).
• Hyperactivity/Impulsivity T-score: -14.0 vs -8.5 placebo (p = .0002).
• Executive Functioning T-score: -13.0 vs -8.1 placebo (p = .0003).
• Defiance/Aggression T-score: -5.7 vs -4.7 placebo (p = .3932).
• Treatment Response Rates:
• ≥ 30% ADHD-RS-5 Reduction: 69.1% vs 50.3% placebo (p < .01).
• ≥ 40% ADHD-RS-5 Reduction: 57.7% vs 42.1% placebo (p < .01).
• ≥ 50% ADHD-RS-5 Reduction: 47.0% vs 31.0% placebo (p < .01).
• CGI-C Score of 1 (“Very Much Improved”) or 2 (“Much Improved”): 50.3% vs 34.5% placebo (p < .01).
• Clinically Meaningful Change (≥ 18-point raw score drop): 47.7% vs 31.7% placebo (p = .0039).

Overview of Efficacy in Children (6–12 Years) and Adults (18–55 Years)

• Children Aged 6–12 Years (N=480): Over 6 weeks, weight-based high-dose centanafadine demonstrated statistically significant improvements vs placebo on the ADHD-RS-5 symptoms total raw score (-16.3 vs -10.8; p < .001), with rapid separation at Week 1. Low-dose centanafadine did not reach statistical significance.
• Adults Aged 18–55 Years: Two 6-week Phase 3 trials evaluated centanafadine sustained-release tablets (200 mg/day and 400 mg/day). Both doses achieved statistically significant and clinically meaningful reductions in adult ADHD symptoms as measured by the Adult ADHD Investigator Symptom Rating Scale (AISRS).

What Changes

Practice Transformation, Dosing, and Safety Considerations

The arrival of centanafadine alters the prescribing landscape by offering a non-controlled, once-daily option with stimulant-like rapid onset and broad symptom efficacy.

| Clinical Paradigm Comparison | | | | | --- | --- | --- | --- | | Feature | Stimulants | Selective Nonstimulants | Centanafadine (NDSRI) | | Mechanism | DA / NE Transporters | NE Transporters | NE, DA, & 5-HT Transporters | | Controlled Status | Schedule II | Non-controlled | Non-controlled | | Onset of Action | Rapid (Days 1–7) | Delayed (2–4+ Weeks) | Rapid (Week 1) | | Executive Function | Moderate Improvement | Modest Improvement | Significant Improvement | | Abuse Potential | High Risk | None | Low Risk |

Dosing and Practical Administration

• Formulation: Centanafadine (SIMTRIYO®) is formulated as a once-daily extended-release capsule.
• Administration Flexibility: Capsules can be swallowed intact with water or opened and sprinkled onto one tablespoon of applesauce for patients with swallowing difficulties, provided the mixture is consumed immediately without chewing.
• No Mandatory Titration: In clinical trials, effective therapeutic doses (such as 328.8 mg daily in adolescents) were initiated directly without required initial dose titration.

Safety, Tolerability, and Monitoring Protocols

Across the clinical development program, centanafadine was generally safe and well-tolerated. Most treatment-emergent adverse events (TEAEs) were mild to moderate in severity.

Adolescent Adverse Event Summary

• Overall TEAE Incidence: 50.3% (328.8 mg), 31.4% (164.4 mg), and 23.8% (placebo).
• Discontinuation Rates Due to Adverse Events: Low across treatment arms—7.9% in the 328.8 mg group, 3.3% in the 164.4 mg group, and 0% in placebo.
• Most Common TEAEs ($\\ge 5\\%$ in any group and higher than placebo):
• Decreased Appetite: 15.2% (328.8 mg), 5.9% (164.4 mg), 2.0% (placebo).
• Nausea: 9.9% (328.8 mg), 5.2% (164.4 mg), 2.7% (placebo).
• Headache: 6.0% (328.8 mg), 7.8% (164.4 mg), 5.4% (placebo).
• Rash: 6.0% (328.8 mg), 2.0% (164.4 mg), 0.7% (placebo).
• Adult TEAE Profile: The most common adverse events reported in adult trials were decreased appetite and headache.

Common TEAE Profile in Adolescents (328.8 mg vs Placebo)

• Decreased Appetite: 15.2% (vs. 2.0% Placebo)
• Nausea: 9.9% (vs 2.7% Placebo)
• Headache: 6.0% (vs 5.4% Placebo)
• Rash: 6.0% (vs 0.7% Placebo)
• Somnolence: 4.0% (vs 2.7% Placebo)

Physical Development, Cardiovascular, and Safety Parameters

• Weight and Growth: In the 6-week adolescent trial, weight loss \>7 % occurred in 4.9% of participants in the 328.8 mg group compared to 0.8% in placebo. Clinically meaningful shifts in age- and sex-adjusted BMI Z-scores (\>0.5 or <-0.5) occurred in <5 % of patients. Clinicians should monitor pediatric growth and weight during treatment, as with other ADHD therapies.
• Cardiovascular & Vital Signs: No meaningful trends or clinically significant mean differences were observed between centanafadine and placebo for blood pressure, heart rate, or electrocardiogram (ECG) parameters.
• Absence of Withdrawal Effects: Evaluation using the Study Medication Withdrawal Questionnaire-Pediatric (SMWQ-P) following abrupt trial discontinuation demonstrated low scores comparable to placebo, confirming an absence of physical withdrawal symptoms.

Practical Clinical Guidance for Prescribers

When evaluating candidates for centanafadine (SIMTRIYO®), healthcare providers should consider the following practice integration principles:

1. Target Candidate Selection: - Patients experiencing inadequate efficacy or tolerability issues (e.g., severe insomnia, emotional blunting) with stimulants. - Adolescents and young adults with prominent executive dysfunction or emotional dysregulation. - Individuals with comorbid substance use disorders, family history of addiction, or heightened risk of medication diversion. - Patients who prefer non-controlled medication regimens. 2. Dosing Strategy: - Ensure prescribed doses match age and weight parameters supported by clinical trial data (e.g., high-dose targets such as 328.8 mg daily in adolescents). - Lower doses (e.g., 164.4 mg in adolescents) were subtherapeutic for primary ADHD core symptom endpoints. 3. Patient Counseling & Monitoring: - Set Onset Expectations: Educate patients that symptom relief may begin as early as Week 1. - Proactive GI & Appetite Management: Inform families that transient decreased appetite or nausea may occur early in treatment. Administering the medication with food can help mitigate gastrointestinal side effects. - Dermatologic Awareness: Advise patients to report mild rashes, which were observed in ~6% of high-dose adolescent patients and generally resolved without severe sequelae.

Conclusion

The FDA approval of centanafadine (SIMTRIYO®) introduces an important new pharmacologic class to the ADHD treatment landscape. By combining the rapid onset of efficacy traditionally associated with stimulants with a low abuse potential and broad efficacy across core symptoms, executive function, and emotional dysregulation, centanafadine offers healthcare providers a valuable addition to individualized ADHD care.

References

1. Ward CL, Childress AC, Jin N, Turkoglu O, Skubiak T, Wilens TE. Centanafadine for attention-deficit/hyperactivity disorder in adolescents: a randomized clinical trial. J Am Acad Child Adolesc Psychiatry. 2026;65(6):805-817. doi:10.1016/j.jaac.2025.06.023
2. Otsuka Pharmaceutical Co., Ltd. Otsuka Pharmaceutical submits New Drug Application to US FDA for centanafadine for the treatment of ADHD in children, adolescents, and adults. Press release. November 24, 2025. Accessed July 27, 2026. https://www.otsuka-us.com/news/otsuka-pharmaceutical-submits-new-drug-application-us-fda-centanafadine-treatment-adhd
3. Otsuka Pharmaceutical Co., Ltd. Otsuka shares FDA review update for centanafadine. Press release. January 27, 2026 / July 24, 2026. Accessed July 27, 2026. https://www.otsuka-us.com/otsuka-shares-fda-review-update-for-centanafadine
4. Kuntz L, Psychiatric Times Editorial Staff. FDA approves centanafadine for ADHD in children, adolescents, and adults. Psychiatric Times. July 25, 2026. Accessed July 27, 2026. https://www.psychiatrictimes.com/view/fda-approves-centanafadine-for-adhd-in-children-adolescents-and-adults