BioMarin Pharmaceutical Inc. and Genzyme Corporation have announced a restructuring of their joint venture regarding Aldurazyme (laronidase), though under the revised structure, the operational responsibilities for BioMarin and Genzyme will not significantly change.

Genzyme will continue to market and sell Aldurazyme for mucopolysaccharidosis I (MPS I) globally, which BioMarin will continue to manufacture.

As of 1 January 2008, instead of sharing all costs and profits equally through their 50 : 50 joint venture, Genzyme will record sales of Aldurazyme and will pay BioMarin a tiered payment ranging from approximately 39.5 to 50 per cent of worldwide net product sales, which will also be recorded by BioMarin as product revenue.

Under the revised structure, payments are projected to result in both BioMarin and Genzyme receiving approximately the same profit as under the original joint venture structure. BioMarin will receive all the benefits from increased manufacturing efficiencies and Genzyme will receive all of the benefits from increased commercialisation efficiencies.

Certain research and development activities related to Aldurazyme and intellectual property will continue to be managed in the joint venture on a 50 : 50 basis.

"This new structure provides both companies a better alignment of financial incentives with operational decisions and represents a more appropriate structure for two companies manufacturing and commercializing multiple products," said Jean-Jacques Bienaim, chief executive officer of BioMarin. "This structure will also reduce management time and provide stronger incentives for each company to maximize the efficiency of its own operations related to Aldurazyme. Lastly, this new structure allows the companies to collaborate and equally share costs on research projects which could lead to important advances for MPS I patients."

About MPS I
MPS I is a rare, progressive, heterogeneous, 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. Aldurazyme addresses the underlying cause of MPS I by replacing the missing enzyme through a weekly infusion. More information about MPS I can be found at www.mps1disease.com.

About Aldurazyme
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. More information on Aldurazyme can be found at www.aldurazyme.com.

The most common side effects associated with treatment with Aldurazyme were upper respiratory tract infection, rash, and injection site reaction. The most common adverse reactions requiring treatment were infusion-related hypersensitivity reactions including flushing, fever, headache, and rash.

The most serious adverse reaction reported with Aldurazyme was an anaphylactic reaction consisting of hives and blockage of the breathing tubes, which occurred in one person. Emergency surgery was required to help this patient breathe. This patient's underlying disease may have contributed to the severity of this reaction. The majority of patients in clinical studies developed an immune response to treatment with Aldurazyme. The clinical significance of this response is unknown. Aldurazyme is available by prescription only.