PRESS RELEASE: BioMarin Re-Acquires Rights to Kuvan in Canada From Merck Serono

BioMarin Re-Acquires Rights to Kuvan in Canada From Merck Serono

NOVATO, Calif., Dec. 18 -- BioMarin Pharmaceutical Inc. announced today that it has re-acquired the Canadian rights for tetrahydrobiopterin (BH4), including Kuvan(TM) (sapropterin dihydrochloride), from Merck Serono, a division of Merck KGaA, Darmstadt, Germany. Kuvan is an oral small molecule for the treatment of phenylketonuria (PKU) developed in partnership with Merck Serono. Based on published literature, there are approximately 1,200 to 1,500 people under the age of 40 with PKU in Canada.

"Acquiring rights to Kuvan in Canada allows BioMarin to better coordinate commercialization efforts in the North American market," said Stephen Aselage, Senior Vice President, Global Commercial Development of BioMarin. "This agreement with Merck Serono comes at an exciting time for the company and the PKU community after Kuvan was approved in the United States last week."

The terms of the agreement specify a reduction in royalties owed to BioMarin on Merck Serono sales outside the United States and Japan. Based on the structure of the amended agreement, the reduction in royalties cannot exceed an undisclosed cap.

About Kuvan

Kuvan(TM) (sapropterin dihydrochloride) Tablets is indicated to reduce blood phenylalanine (Phe) levels in patients with hyperphenylalaninemia (HPA) due to tetrahydrobiopterin- (BH4-) responsive phenylketonuria (PKU). Kuvan is to be used in conjunction with a Phe-restricted diet.

The active ingredient in Kuvan, sapropterin dihydrochloride, is the synthetic form of 6R-BH4 (tetrahydrobiopterin), a naturally occurring enzyme cofactor that works in conjunction with phenylalanine hydroxylase (PAH) to metabolize Phe. BioMarin and Merck Serono estimate that Kuvan could be a potential treatment option for approximately 30 percent to 50 percent of the estimated 50,000 identified PKU patients in the developed world.

Kuvan has received orphan drug designation from both the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMEA). Kuvan has received seven years of market exclusivity in the United States. In November 2007, Merck Serono submitted a Marketing Authorization Application (MAA) to the EMEA for sapropterin dihydrochloride as an oral treatment for patients suffering from HPA due to PKU or BH4 deficiency. If approved in the EU, it will receive 10 years of market exclusivity for this indication.

About PKU

PKU, a genetic disorder affecting approximately 50,000 diagnosed patients in the developed world, is caused by a deficiency of the enzyme phenylalanine hydroxylase. PAH is required for the metabolism of phenylalanine, an essential amino acid found in most protein-containing foods. If the active enzyme is not present in sufficient quantities, Phe accumulates to abnormally high levels in the blood and becomes toxic to the brain, resulting in a variety of complications including severe mental retardation and brain damage, mental illness, seizures, tremors, and limited cognitive ability. As a result of newborn screening efforts implemented in the 1960s and early 1970s, virtually all PKU patients under the age of 40 in developed countries have been diagnosed at birth. Currently, PKU can only be managed by a Phe-restricted diet, which is supplemented by nutritional replacement products, like formulas and specially-manufactured foods; however, the strict diet is difficult for most patients to adhere to the extent needed for achieving adequate control of blood Phe levels. To learn more about PKU, please visit http://www.PKU.com. Information on this website is not incorporated by reference into this press release.

About BioMarin

BioMarin develops and commercializes innovative biopharmaceuticals for serious diseases and medical conditions. The company's product portfolio comprises three approved products and multiple clinical and preclinical product candidates. Approved products include Naglazyme(R) (galsulfase) for mucopolysaccharidosis VI (MPS VI), a product wholly developed and commercialized by BioMarin; Aldurazyme(R) (laronidase) for mucopolysaccharidosis I (MPS I), a product which BioMarin developed through a 50/50 joint venture with Genzyme Corporation; and Kuvan(TM) (sapropterin dihydrochloride) Tablets, a product for the treatment of phenylketonuria (PKU), developed in partnership with Merck Serono, a division of Merck KGaA of Darmstadt, Germany. Other product candidates include 6R-BH4 for cardiovascular indications, which is currently in Phase 2 clinical development for the treatment of peripheral arterial disease and sickle cell disease, and PEG-PAL (PEGylated recombinant phenylalanine ammonia lyase) for the treatment of PKU. For additional information, please visit http://www.BMRN.com. Information on BioMarin's website is not incorporated by reference into this press release.

Forward-Looking Statement

This press release contains forward-looking statements about the business prospects of BioMarin Pharmaceutical Inc., including, without limitation, statements about: the use of its product Kuvan; the potential market for Kuvan; expectations regarding filings with regulatory agencies; and the development of 6R-BH4 for other indications. 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: the practices of physicians in using Kuvan; the actual response in patients using Kuvan in commercial distribution; the content and timing of decisions by the U.S. Food and Drug Administration, the European Medicines Agency and other regulatory authorities concerning Kuvan; results and timing of current and planned clinical trials of 6R-BH4 for other indications; and those factors detailed in BioMarin's filings with the Securities and Exchange Commission, including, without limitation, the factors contained under the caption "Risk Factors" in BioMarin's 2006 Annual Report on Form 10-K, as amended, and the factors contained in BioMarin's reports on Form 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.