Axsome's Sunosi Shows Promise in Phase 3 ADHD Trial, Adding to Recent Successes

Axsome Therapeutics, a rapidly growing central nervous system (CNS) specialist, has reported positive results from a phase 3 trial of Sunosi (solriamfetol) in adults with attention deficit hyperactivity disorder (ADHD). This development marks another significant milestone for the New York City-based company, following recent approvals and promising clinical outcomes.

Sunosi's Success in ADHD Trial

The phase 3 trial, code-named Focus, evaluated Sunosi's efficacy in 516 adults with ADHD across three treatment arms: placebo, 150 mg dose, and 300 mg dose. The study achieved its primary and key secondary endpoints, demonstrating substantial and statistically significant improvement in ADHD symptoms compared to placebo.

Key findings from the trial include:

• Patients receiving the 150 mg dose of Sunosi experienced an average reduction of 17.7 points from baseline on the Adult ADHD Investigator Symptom Rating Scale (AISRS), compared to 14.3 points for placebo.
• Overall, Sunosi provided a 45% mean reduction from baseline in ADHD symptoms.
• 54% of patients in the 150 mg arm achieved clinical response (defined as a 30% improvement from baseline), compared to 41% of those on placebo.
• The 300 mg dose showed numerically superior results to placebo but did not reach statistical significance.

Dr. Gregory Mattingly, president of the American Professional Society for ADHD and Related Disorders, commented on the results, stating, "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."

Axsome's Strategic Acquisition and Development

Axsome acquired the rights to Sunosi from Jazz Pharmaceuticals in 2022 for $53 million upfront. Originally approved by the FDA in 2019 for narcolepsy and obstructive sleep apnea (OSA), Sunosi is a dopamine and norepinephrine reuptake inhibitor (DNRI). The acquisition was based on the belief that Axsome could better develop the drug for additional indications, including major depressive disorder (MDD), binge eating disorder (BED), and excessive sleepiness associated with shift work disorder (SWD).

Since the acquisition, Sunosi has shown improved commercial performance under Axsome's management:

• 2024 sales reached $94 million, a 26% increase from 2023.
• This growth contrasts with the drug's performance under Jazz Pharmaceuticals, which reported sales of $58 million in 2021.

Axsome's Recent Successes and Future Prospects

The positive ADHD trial results add to a series of recent achievements for Axsome:

1. FDA approval of migraine treatment Symbravo two months ago, projected as a potential blockbuster.
2. Successful commercialization of Auvelity for major depressive disorder (MDD), with 2024 sales reaching $291 million.
3. Ongoing development of Sunosi for MDD, with phase 3 Paradigm study results expected in the first quarter.
4. Progress on the regulatory path for AXS-05, an Alzheimer's disease treatment candidate.

CEO Herriot Tabuteau, M.D., announced plans to initiate a trial of Sunosi in pediatric ADHD patients this year. However, analysts suggest that separate trials for adolescents (13-17 years) and younger children may be necessary to meet FDA guidelines.

As Axsome continues to expand its CNS portfolio and demonstrate clinical success, the company's market capitalization has surged to $5.3 billion, reflecting investor confidence in its growth strategy and pipeline potential.