Dive Brief:
An experimental Duchenne muscular dystrophy gene therapy from Regenxbio has met its main objective in a pivotal trial, positioning the company to seek an accelerated regulatory clearance in the U.S.
Three months after treatment with Regenxbio’s therapy, RGX-202, 28 of the 30 study participants receiving muscle biopsies produced at least 10% of normal levels of a diminutive protein, “microdystrophin,” believed to help Duchenne patients. That result hit the trial’s main goal and passed a key threshold needed to support an approval. Nine volunteers with at least one year of follow-up also demonstrated statistically significant improvements, from the study’s start, on multiple tests of motor function.
Regenxbio did report two serious adverse events among treatment recipients — one case of heart inflammation and another of asymptomatic liver injury. Both were “easily managed and resolved within weeks” without further incident, and the average levels of liver inflammation markers in those who got RGX-202 didn’t surpass the “upper limit of normal.” Still, company shares fell by more than 35% as the safety findings “muddy the update,” wrote Leerink Partners’ analyst Mani Foroohar.
