Highlights

  • DAZALS Phase 2 trial did not meet its primary efficacy endpoint related to ALS functional score improvement.
  • Secondary endpoint met: 300 mg dazucorilant group showed improved survival at 24 weeks compared to placebo.
  • One-year exploratory analysis indicates continued survival benefit for patients on higher-dose dazucorilant.

Corcept Therapeutics Incorporated (NASDAQ: CORT) is a commercial-stage biopharmaceutical company headquartered in the United States. It focuses on discovering and developing therapies that modulate the effects of cortisol to treat a variety of serious disorders in endocrinology, oncology, metabolism, and neurology.

The company has reported results from its Phase 2 DAZALS clinical trial evaluating dazucorilant in patients with amyotrophic lateral sclerosis (ALS). The findings, presented at the European Network to Cure ALS (ENCALS) 2025 annual meeting, showed that while the study did not achieve its primary endpoint of improved ALS Functional Rating Scale-Revised (ALSFRS-R) scores, it did meet its secondary endpoint of improved overall survival for patients receiving the higher 300 mg dose.

The DAZALS study enrolled 249 patients who were randomized equally to receive either 150 mg or 300 mg of dazucorilant or placebo daily over a 24-week period. Patients who completed this treatment phase were offered participation in an open-label extension study with a 300 mg daily dose.

According to the company, the primary endpoint—difference in ALSFRS-R score change from baseline—was not met. However, a statistically significant difference in overall survival was observed at week 24. Among the 83 patients who received 300 mg of dazucorilant, no deaths were reported at the 24-week point, whereas five deaths occurred in the 82-patient placebo group (p = 0.02).

Further exploratory analysis at the one-year mark revealed continued survival benefit. Patients initially randomized to the 300 mg group had significantly higher survival rates than those who received only placebo, with a hazard ratio of 0.16 (p = 0.0009). Additionally, patients who were exposed to 300 mg of dazucorilant for more than 24 weeks—either during the treatment phase or in the extension—also showed survival advantages compared to those who received lower doses or only placebo (hazard ratio: 0.36; p = 0.02). These trends are based on ongoing data from the extension study.

Safety data from the trial indicated that dazucorilant was generally well tolerated. The majority (92%) of adverse events were classified as mild or moderate in severity. Rates of serious adverse events were comparable between the dazucorilant and placebo groups. The most frequently reported side effect was dose-related, transient abdominal pain. Corcept stated that it is now engaging with regulatory bodies in the United States and Europe to discuss next steps for dazucorilant's development in ALS. The company acknowledged the significance of the observed survival benefit despite the trial’s inability to meet its primary functional outcome.