BioMarin Pharmaceutical Inc and Genzyme General announced that the U.S. Food and Drug Administration (FDA) has granted marketing approval for Aldurazyme (laronidase), the first specific treatment approved for people with mucopolysaccharidosis I (MPS I).

Aldurazyme is indicated for patients with the Hurler and Hurler-Scheie forms of MPS I, and for Scheie patients with moderate to severe symptoms. The risks and benefits of treating mildly affected patients with the Scheie form have not been established. Aldurazyme has not been evaluated for effects on the central nervous system manifestations of the disorder.

Clinical trials have demonstrated that Aldurazyme can provide clinically important benefits for patients, including improved pulmonary function and walking ability. Aldurazyme has also been shown to be effective at reducing the excess carbohydrates that are stored in the organs of patients with MPS I, providing evidence that the enzyme is effective at a biochemical level.

As the first drug ever approved for MPS I, Aldurazyme has been granted orphan drug status in the United States, which confers seven years of market exclusivity.

"We have observed remarkable improvements in the lives of patients after treatment with Aldurazyme," said Joseph Muenzer, Associate Professor of Pediatrics, University of North Carolina, and a principal investigator for the Aldurazyme clinical trials. "Prior to development of this enzyme replacement therapy, physicians were limited primarily to managing the wide array of symptoms in MPS I patients. Now, by addressing the underlying pathophysiology, we have the opportunity to change the course of this disease for the better."

MPS I is a rare, progressive, debilitating disease caused by a deficiency of the enzyme alpha L-iduronidase that affects an estimated 3,000 to 4,000 people worldwide, including approximately 1,000 in the United States. Patients who lack this enzyme accumulate a carbohydrate called glycosaminoglycan (GAG) in tissues and organ systems. A majority of patients die before adulthood due to a wide range of problems related to the disease, including progressive damage to the heart, lungs, liver, and kidneys.

BioMarin and Genzyme have agreed with the FDA on a number of post-marketing commitments. The companies will complete their previously announced study that was initiated in December of 2002 to evaluate the safety and pharmacokinetics of Aldurazyme in patients less than 5 years of age. In addition, they will conduct an open-label dose optimization study in approximately 32 patients, and continue the Phase 3 extension study for a total of 4 years from study initiation. In a registry setting, the companies will also obtain long-term information related to the natural history of MPS I and the safety and efficacy of Aldurazyme.