Capricor Therapeutics (CAPR) saw its shares drop 8.68% in after-hours trading on Wednesday, following a dramatic intraday surge fueled by positive Phase 3 trial results for its Duchenne muscular dystrophy (DMD) treatment, Deramiocel.

The stock had skyrocketed earlier in the day, with gains of up to 399%, after the company announced that its HOPE-3 study met both primary and secondary endpoints, demonstrating significant skeletal and cardiac benefits for patients. The results were seen as a potential breakthrough for the rare disease treatment.

The after-hours decline is likely due to profit-taking by investors who capitalized on the day's substantial gains, a common occurrence following such sharp rallies. The stock's volatility was also evident through multiple trading halts during the session.