William Sly Honored at WORLD Symposium

William Sly, M.D., was recognized for his contributions to the development of an enzyme replacement therapy (ERT) for mucopolysaccharidosis type VII (MPS VII) or Sly disease. Dr. Sly described the first patient with this rare genetic disorder over 40 years ago and spent much of his research career investigating the cause of the disease, a deficiency of beta-glucuronidase, and studying enzyme pathways and treatments in mouse and dog models of the disease.

In 2016, Ultragenyx, a company dedicated to discovering treatments for rare and ultrarare diseases, developed an ERT therapy for MPS VII and successfully administered the treatment to a patient. The drug, MEPSEVII, received FDA approval in November 2017.

At the recent WORLD Symposium in San Diego, CA, Christine Haller, M.D., was awarded the New Treatment Award for her part in the development and approval of MEPSEVII. She called Dr. Sly on-stage to share in the award in recognition of his important work that helped lead to this treatment.


Christine Haller, M.D., of Ultragenyx
and William Sly, M.D.

Department of Biochemistry and Molecular Biology