Scientific Protocol

Scientific protocol for treating children with severe MPS I with a combination of Stem Cell Transplantation and Enzyme Replacement Therapy at the University of Minnesota

The University of Minnesota has been a pioneer in the treatment of children with severe MPS I, also called Hurler syndrome, and other storage disorders using stem cell transplantation (i.e., bone marrow or cord blood transplantation). To date, approximately 100 transplants have been performed at the University of Minnesota for Hurler syndrome alone. We are committed to the comprehensive and long-term care of these children, including evaluation and treatment of issues unique to these children before and after transplantation. Our team has extensive and long-standing experience in the assessment and treatment of complications of Hurler syndrome, including problems of the eyes, ears, lungs, heart, bones and joints, as well as neurological difficulties. The University of Minnesota constantly strives to improve results and outcomes following stem cell transplantation. The most recent such innovation at Minnesota (for children with Hurler syndrome) is the development of a scientific protocol for the combined use of enzyme replacement therapy and stem cell transplantation. The basis of this combination therapy is as follows:

Hurler syndrome is the most severe form of Mucopolysaccharidosis I, and is characterized by progressive mental regression, heart and airway disease as well as bony deformities; death typically results in the first 10 years of life.

Laronidase (trade name Aldurazyme) is the commercial preparation of the enzyme that is deficient in Hurler syndrome. Laronidase enzyme replacement therapy (ERT) does not directly benefit the brain in children with Hurler syndrome, and hence does not represent a satisfactory therapy in itself. However, Laronidase can provide other valuable benefits: in particular, it clears airway obstruction and improves lung function.

Stem cell transplantation is the only proven therapy that can prevent the progressive mental retardation and give hope for long-term survival. However, stem cell transplantation is not free of risks and complications. Children with Hurler syndrome are particularly prone to get lung and airway related complications during transplantation. Based on these observations, we believe that treating with (ERT) for 12 weeks before and 8 weeks after stem cell transplantation will decrease complications associated with stem cell transplantation, thereby improve outcomes and survival in children with Hurler syndrome undergoing transplantation. The University of Minnesota has developed a protocol (the first of its kind) to systematically administer this therapy in a uniform manner as well as to study the results of this combination therapy as compared to stem cell transplantation alone.

For more information on this protocol, or to talk to one of the University of Minnesota stem cell transplant physicians, please contact one of the following:

Satkiran Grewal, MD,
Chester B. Whitley, PhD, MD
800-888-8642 (Beeper 8325)
Paul Orchard, MD