BioMarin Pharmaceutical Inc. (Nasdaq and SWX: BMRN) today announced that the U.S. Food and Drug Administration (FDA) has accepted for filing and assigned six-month review to the Biologics License Application (BLA) for rhASB (galsulfase), the company's investigational enzyme replacement therapy for the treatment of mucopolysaccharidosis VI (MPS VI). The FDA will take action on the application, under the Prescription Drug User Fee Act (PDUFA), by May 31, 2005.

A six-month review is typically granted to drugs that, if approved, would be a significant improvement in the safety or effectiveness of the treatment, diagnosis, or prevention of a serious or life-threatening disease. The FDA previously granted rhASB orphan drug designation, a designation conferred upon investigational products for diseases that affect fewer 200,000 patients in the United States. Products with orphan drug designation that are the first to be approved for a specific indication have seven years market exclusivity within the United States.

About rhASB

rhASB is an investigational enzyme replacement therapy designed to address the underlying enzyme deficiency associated with MPS VI. If approved, rhASB could become the first drug therapy for the treatment of MPS VI.

About MPS VI

MPS VI, also known as Maroteaux-Lamy Syndrome, is an inherited debilitating, life-threatening disease which affects approximately 1,100 people worldwide. MPS VI is caused by the deficiency of N-acetylgalactosamine 4-sulfatase (arylsulfatase B), a lysosomal enzyme normally required for the breakdown of certain complex carbohydrates known as glycosaminoglycans (GAGs). This enzyme deficiency leads to the accumulation of GAGs in the lysosomes of cells, giving rise to progressive cellular, tissue and organ system dysfunction. Debilitating symptoms can include impaired cardiac and pulmonary function, delayed physical development, skeletal and joint deformities, impaired vision and hearing, sleep apnea, and reduced endurance. The majority of people with MPS VI die from disease-related complications between childhood and early adulthood.

About BioMarin

BioMarin develops and commercializes innovative biopharmaceuticals for serious diseases and medical conditions. The company's product portfolio is comprised of two approved products, Orapred(R) (prednisolone sodium phosphate oral solution) for severe asthma and Aldurazyme(R) (laronidase) for mucopolysaccharidosis I (MPS I), and multiple investigational product candidates including rhASB (galsulfase), a Phase 3 product candidate for the treatment of MPS VI, and Phenoptin(TM) (sapropterin hydrochloride), a Phase 2 product candidate for the treatment of phenylketonuria (PKU). For additional information, please visit www.BMRN.com.

Forward-Looking Statement

This press release contains forward-looking statements about the business prospects of BioMarin Pharmaceutical Inc., including, without limitation, statements about: the development of rhASB; the expected timing of a response by the FDA on the rhASB BLA; and filings with and actions by regulatory authorities. These forward-looking statements are predictions and involve risks and uncertainties such that actual results may differ materially from these statements. These risks and uncertainties include, among others: results and timing of clinical trials; the content and timing of decisions by the FDA, the European Medicines Agency and other regulatory authorities concerning rhASB; and those factors detailed in BioMarin's filings with the Securities and Exchange Commission, including, without limitation, the factors contained under the caption "Factors That May Affect Future Results" in BioMarin's 2003 Annual Report on Form 10-K and the factors contained in BioMarin's reports on Forms 10-Q and 8-K. Stockholders are urged not to place undue reliance on forward-looking statements, which speak only as of the date hereof. BioMarin is under no obligation, and expressly disclaims any obligation, to update or alter any forward-looking statement, whether as a result of new information, future events or otherwise.

NOTE: Aldurazyme(R) is a registered trademark of BioMarin/Genzyme LLC.

Orapred(R) is a registered trademark of Medicis Pediatrics, Inc. and is used under license.

   Contacts:
   Investors                           Media
   Joshua A. Grass                     Susan Ferris
   BioMarin Pharmaceutical Inc.        BioMarin Pharmaceutical Inc.
   415-506-6777                        415-506-6701

SOURCE: BioMarin Pharmaceutical Inc.