Sarepta Therapeutics stock jumped after the company unveiled positive top-line results for a study measuring the efficacy of Elevidys, its controversial blockbuster treatment for Duchenne muscular dystrophy. Patients in the study showed “statistically significant, clinically meaningful and durable efficacy across all key motor function measures” three years after treatment, Sarepta said. The mean North Star Ambulatory Assessment score, a 17-item scale that grades functional motor abilities in patients, remained above baseline for the treated group, while the external control group “continued to show the expected age-related decline below their baseline score,” Sarepta said.