Corcept's Mixed Results in ALS and Ovarian Cancer Trials Highlight Potential and Challenges

Corcept Therapeutics, a biopharmaceutical company focusing on cortisol modulation, has released results from two significant clinical trials, showcasing both promise and setbacks in their drug development pipeline. The company's efforts in amyotrophic lateral sclerosis (ALS) and platinum-resistant ovarian cancer have yielded complex outcomes, sparking discussions about the future of these treatments.

Dazucorilant in ALS: Survival Benefit Despite Missed Primary Endpoint

Corcept's investigational cortisol modulator, dazucorilant, failed to meet its primary endpoint in a Phase II trial for ALS patients. The study, which evaluated 249 patients across North America and Europe, did not show a statistically significant improvement in the ALS Functional Rating Scale-Revised (ALSFRS-R) scores, a measure of disability and respiratory function.

However, an exploratory analysis revealed a potentially significant benefit in overall survival. At the 24-week mark, none of the 83 patients receiving the 300 mg dose of dazucorilant had died, compared to five deaths in the 82-patient placebo group. Extended analysis at one year showed that dazucorilant treatment reduced the risk of death by 84% versus placebo.

Despite these promising survival data, the drug's safety profile raised concerns. Patients receiving dazucorilant experienced increased gastrointestinal adverse events, with 19% of the 300 mg group reporting at least one severe treatment-emergent adverse event (TEAE), compared to 13% in the placebo group.

Bill Guyer, Corcept's Chief Development Officer, emphasized the urgent need for life-extending ALS treatments and stated that the company is "working with regulatory authorities to determine the optimal path for advancing dazucorilant."

Relacorilant Shows Promise in Ovarian Cancer Trial

In a separate development, Corcept presented Phase III data for relacorilant, a selective glucocorticoid receptor antagonist, in combination with nab-paclitaxel for the treatment of platinum-resistant ovarian cancer. The results, unveiled at the 2025 American Society of Clinical Oncology conference, demonstrated that the relacorilant regimen reduced the risk of disease progression by 30% compared to nab-paclitaxel alone.

The study met its primary endpoint, with a 29% improvement in progression-free survival for patients treated with the relacorilant combination. However, analysts at Truist Securities noted potential safety concerns, particularly regarding the tolerability profile of relacorilant.

Corcept plans to submit a regulatory application for relacorilant in the third quarter of this year, buoyed by what Truist analysts described as a "favorable" overall profile that they "expect approval with commercial traction."

Market Impact and Future Outlook

The mixed results from these trials have had a nuanced impact on Corcept's market position. Following the announcement of the ALS trial results, Corcept's stock saw a modest increase of more than 1.4% in premarket trading, with the company valued at a $7.4 billion market cap.

Analysts at Truist Securities characterized the ALS data as a "mixed bag" but noted that the readout is unlikely to be "incremental" to Corcept's overall stock narrative. The firm does not include dazucorilant in its valuation for the biotech, suggesting that the market's response may be more heavily influenced by developments in Corcept's other pipeline products, such as relacorilant.

As Corcept navigates the complex landscape of drug development, the company's ability to leverage these mixed results into successful regulatory approvals and commercial products will be closely watched by investors and the broader pharmaceutical industry.