Corcept's ALS Drug Shows Promise in Survival Data Despite Phase 2 Failure

Corcept Therapeutics has unveiled promising survival data from its previously failed phase 2 trial for amyotrophic lateral sclerosis (ALS), potentially breathing new life into the development of dazucorilant. The company presented these findings at the European Network to Cure ALS 2025 annual meeting, shedding light on the drug's potential benefits despite its initial setback.

Survival Benefit Emerges as Silver Lining

While the primary endpoint of reducing decline in motor skills and other functional criteria was not met, Corcept highlighted a significant improvement in patient survival among those receiving the higher 300 mg dose of dazucorilant. At the 24-week mark, none of the 83 patients in this cohort had died, compared to two deaths in the 150 mg arm and five in the placebo group.

The survival benefit appeared to persist in a subsequent 12-month analysis. Corcept reported 14 deaths in the 300 mg group, compared to 23 in the 150 mg group and 21 in the placebo arm. This data suggests a potential long-term survival advantage for patients receiving the higher dose of dazucorilant.

Safety Profile and Adverse Events

Despite the initial report of "substantially more gastrointestinal upset" associated with dazucorilant, Corcept now characterizes the drug's safety profile as "acceptable." The company noted that 92% of adverse events were mild to moderate in severity. However, the incidence of severe treatment-emergent adverse events (TEAEs) was slightly higher in the treatment groups, with 19% of patients in the 300 mg group experiencing at least one severe TEAE, compared to 17% in the 150 mg group and 13% in the placebo cohort.

Importantly, no patients in the 300 mg group died as a result of a TEAE, while two patients in the 150 mg group and four in the placebo group did experience fatal TEAEs.

Future Prospects and Regulatory Path

Bill Guyer, Corcept's Chief Development Officer, emphasized the urgent need for life-extending medications in ALS treatment. The company is now engaging with regulatory authorities to determine the best path forward for dazucorilant's development.

This potential turnaround for dazucorilant comes as Corcept awaits an FDA approval decision for relacorilant, another drug in its pipeline that showed success in a phase 3 trial for Cushing's syndrome last year. The decision is expected by the end of the year.

As news of the survival data broke, Corcept's stock saw a modest increase of more than 1.4% in premarket trading, with the company's market capitalization standing at $7.4 billion.