Biomarker breakthrough unleashes MPS therapies

Three biotech companies, Denali, RegenxBio and Ultragenyx, announced advances this month in the development of treatments for neurodegenerative effects of mucopolysaccharidoses, a group of devastating, progressive ultrarare diseases. The burst of progress, made possible by FDA’s acceptance of a biomarker, follows years of frustration for the families of MPS patients who have seen multiple therapies abandoned or stalled because manufacturers couldn’t see a viable regulatory path to approval.

FDA’s agreement to allow the companies to use a biomarker as the basis for accelerated approval of neuronal MPS therapies marks an important inflection point, both for the treatment of MPS, and more broadly for efforts to develop medicines for patients with other rare disorders...