Axsome’s Sunosi Trial Yields Mixed Results, Showing Promise for MDD with Daytime Sleepiness

In a recent announcement, Axsome Therapeutics revealed that its investigational drug, Sunosi (solriamfetol), has demonstrated mixed results in a phase 3 trial aimed at treating patients with major depressive disorder (MDD), particularly those experiencing excessive daytime sleepiness (EDS). A week after celebrating a successful phase 3 trial for the same compound in attention-deficit/hyperactivity disorder (ADHD), the company is now shifting focus as it evaluates its prospects in the realm of depression.

Trial Overview and Results

The phase 3, proof-of-concept study sought to investigate the efficacy of Sunosi in patients diagnosed with MDD, examining the outcomes for those both with and without EDS. Although the trial did not meet its primary endpoint across the entire patient population, Axsome pointed to promising improvements specifically among the subset of patients suffering from EDS.

According to Axsome’s CEO and founder, Herriot Tabuteau, M.D., “The promising results with solriamfetol in MDD patients with severe EDS align with its known pharmacology and support its further evaluation in this potentially new indication.” This sentiment underscores the hope that the drug may address a significant gap in treatment options for MDD patients plagued by daytime drowsiness.

Key Findings

The six-week proof-of-concept study enrolled 51 participants suffering from severe EDS and recorded daily treatment with a 300-mg dose of Sunosi. The results indicated “clinically meaningful and numerically greater improvements compared to placebo” across multiple efficacy measures, including the Montgomery-Åsberg Depression Rating Scale. However, in a larger cohort of 291 patients without severe EDS, no significant difference was observed compared to the placebo group.

This stark contrast highlights the prevalence of EDS in MDD, affecting approximately half of those diagnosed with the disorder, according to Axsome’s findings. Additionally, the company emphasized a notable gap in treatment alternatives, as there are currently no FDA-approved medications specifically targeting MDD with EDS.

Future Directions for Axsome

Looking ahead, Axsome plans to initiate a phase 3 trial targeting MDD patients with EDS later this year. This strategic decision aligns with the encouraging data garnered from the recent trial and reflects the company’s commitment to expanding the therapeutic applications of Sunosi.

Background on Sunosi

Axsome acquired Sunosi from Jazz Pharmaceuticals in 2020 for an upfront payment of $53 million. The drug originally received FDA approval in 2019 as a treatment for EDS associated with narcolepsy or obstructive sleep apnea, functioning as a dopamine and norepinephrine reuptake inhibitor. In addition to its recent endeavors in ADHD and MDD, Axsome is exploring the drug’s potential applications in treating binge eating disorder and excessive sleepiness caused by shift work disorder.

Market Potential and Sales Performance

Despite its challenges, Sunosi’s potential within the market remains significant. Analysts from Leerink have projected peak sales of approximately $500 million upon its full approval and market integration. Although the drug’s sales under Jazz peaked at $58 million in 2021, its trajectory improved under Axsome, with reported sales reaching $94 million last year.

The recent trial misstep represents a rare setback for Axsome, a company that has been on a winning streak. It recently received FDA approval for its migraine treatment Symbravo, which may position itself as a blockbuster. Axsome’s earlier approval for its MDD treatment Auvelity generated impressive sales of $291 million last year, further solidifying the company’s status as a key player in the pharmaceutical industry.

Conclusion

While Axsome Therapeutics faced challenges in the recent Sunosi trial for MDD, the promising results observed in patients with EDS could pave the way for future developments. The company’s commitment to further research in this new indication indicates a potential shift in treatment paradigms for MDD patients suffering from daytime sleepiness. As the landscape of psychiatric treatment continues to evolve, Axsome stands at the forefront, exploring the multifaceted applications of its innovative therapies.