Phase 3 Trial Success: Solriamfetol for the Treatment of Adults With ADHD

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Axsome Therapeutics today announced that the FOCUS phase 3 trial of solriamfetol for the treatment of attention-deficit/hyperactivity disorder (ADHD) achieved its primary and key secondary endpoints, demonstrating statistically significant improvements in ADHD symptoms and disease severity compared with placebo.

The FOCUS study was a randomized, double-blind, placebo-controlled, multicenter, US trial, in which 516 adult participants with ADHD were randomized to receive solriamfetol 150 mg, solriamfetol 300 mg, or placebo once daily for 6 weeks. The study achieved its primary endpoint: a statistically significant reduction in the Adult ADHD Investigator Symptom Rating Scale (AISRS) total score compared with placebo at week 6, with mean reductions from baseline of 17.7 points for solriamfetol 150 mg and 14.3 points for placebo (P=0.039). The overall improvement with solriamfetol at week 6 represents a 45% mean reduction from baseline in ADHD symptoms. Improvements in the AISRS total score were greater with solriamfetol compared with placebo starting as early as week 1 (P=0.036). Clinical response, defined as greater than or equal to 30% improvement from baseline in the AISRS total score, was achieved by a statistically significantly greater percentage of patients treated with solriamfetol 150 mg (53.5%) compared with those receiving placebo (41.3%) at week 6 (P =0.024).

“ADHD substantially impairs social, academic, and occupational functioning, while negatively impacting patient quality of life and increasing the risk of morbidity and mortality. The results of the FOCUS trial demonstrate that solriamfetol was able to reduce mean ADHD symptom burden by nearly 50%, which contributed to significant reductions in disease severity,” said Gregory Mattingly, MD, associate clinical professor of psychiatry at the Washington University School of Medicine and president of the American Professional Society for ADHD and Related Disorders. “These results are especially promising as part of a comprehensive wellness plan for individuals with ADHD. The symptom improvements observed with solriamfetol were accompanied by a favorable safety and tolerability profile. Based on these compelling data, solriamfetol has the potential to be an important new treatment option for adult patients living with ADHD.”

The study also achieved the key secondary endpoint by statistically significantly reducing overall ADHD disease severity compared with placebo, as assessed by the Clinical Global Impression of Severity (CGI-S) for ADHD, at week 6 (P=0.017). Results on the primary and key secondary endpoints for the exploratory 300 mg solriamfetol dose were numerically superior compared with placebo but were not statistically significant.

As to safety profile, solriamfetol was safe and well tolerated in the trial, with an adverse effect profile that was consistent with previous research. Rates of adverse events were dose dependent. There were no serious adverse events reported in the trial.

“We are pleased with the positive results of the FOCUS trial which provide the first evidence from a multicenter controlled trial of the efficacy of solriamfetol in the treatment of ADHD. ADHD is a serious, heterogenous, and prevalent condition. We look forward to advancing the development of solriamfetol as a new, differentiated potential treatment for the millions of patients living ADHD. With these results in the adult population in hand, we plan to initiate a trial in pediatric patients this year,” said Herriot Tabuteau, MD, chief executive officer of Axsome.

This news highlights an important diagnostic issue: adult ADHD. As recent CDC data show, over 50% of adults with ADHD were diagnosed in adulthood, with a higher prevalence in women compared with men.^2.3 This treatment could provide another treatment option to adults struggling with management of their ADHD symptoms.

References

1. Axsome Therapeutics announces focus phase 3 trial of solriamfetol in adults with attention deficit hyperactivity disorder (ADHD) achieves primary endpoint. News release. March 25, 2025. https://axsometherapeuticsinc.gcs-web.com/news-releases/news-release-details/axsome-therapeutics-announces-focus-phase-3-trial-solriamfetol

2. Mattingly G, Childress A. Clinical implications of attention-deficit/hyperactivity disorder in adults: what new data on diagnostic trends, treatment barriers, and telehealth utilization tell us. J Clin Psychiatry. 2024;85:4.

3. Mattingly G. Insights into the new CDC data on adult ADHD. Psychiatric Times. October 10, 2024. https://www.psychiatrictimes.com/view/insights-into-the-new-cdc-data-on-adult-adhd