Press Release

December 17, 2007
Asubio Pharma Co., Ltd.

Asubio Pharma's Congenital Metabolic Abnormalities Agent Biopten
Approved by U.S. Food and Drug Administration for
Treatment of BH4 Responsive Hyperphenylalaninemia

Asubio Pharma Co., Ltd. (Asubio Pharma; Head Office: Minato-ku, Tokyo; President & CEO: Seiichi Yokoyama), one of the group companies of DAIICHI SANKYO COMPANY, LIMITED, announced that BioMarin Pharmaceutical Inc. (BioMarin; Head Office: Novato, California, U.S.A.; Chief Executive Officer: Jean-Jacques Bienaimé) received notification of approval on December 13 from the U.S. Food and Drug Administration (FDA) for the congenital metabolic abnormalities agent Biopten (sapropterin hydrochloride, BH4), which it licensed from Asubio Pharma, for the treatment of BH4 responsive hyperphenylalaninemia (HPA).

Asubio Pharma, previously Daiichi Suntory Pharma Co., Ltd., entered into a license agreement with BioMarin for BH4 in November 2004. Based on this agreement, BioMarin conducted clinical trials of BH4 in Europe and the United States for the indication of HPA and in May 2007 applied for approval from the FDA.

BioMarin released an announcement concerning this matter on December 13, 2007 (local time).

Reference:

About Biopten

Biopten, a congenital metabolic abnormalities agent, was developed by Suntory Limited (now Asubio Pharma Co., Ltd.) for the treatment of atypical HPA and launched in 1992 in Japan (marketed by Maruho Co., Ltd.). HPA is an inherited disorder of abnormal phenylalanine metabolism which manifests in mental retardation and other symptoms in the central nervous system, melanin deficiency and urine odor. The condition results from a deficiency of the enzyme phenylalanine hydroxylase (HPA) or its cofactor tetrahydrobiopterin, BH4 (atypical HPA). BH4 responsive HPA is so named because in recent years it has been found that treatment with BH4 improved phenylalanine metabolism in those with a normal level of BH4. BioMarin pursued development for the indication of phenylketonuria (PKU), also a form of responsive HPA, and applied for approval from the FDA.

Corporate Profile

Asubio Pharma Co., Ltd.

Head Office:	2-9-11 Akasaka, Minato-ku, Tokyo , Japan
President & CEO:	Seiichi Yokoyama
Date of Inauguration:	December 27, 2002
Capital:	¥11.0 billion
Stockholder:	DAIICHI SANKYO COMPANY, LIMITED, 100%
Employees:	About 330 (including group companies)
Primary Business:	Research and development, manufacture and sales of pharmaceuticals

BioMarin Pharmaceutical Inc.

Head Office:	105 Digital Drive, Novato, CA 94949, U.S.A.
Chief Executive Officer:	Jean-Jacques Bienaimé
Date of Establishment:	1997
Capital:	$1.7 billion
Employees:	About 450
Primary Business:	Research and development of pharmaceuticals