Press Release

GENEVA, November 25 /PRNewswire/ -- Merck Serono, a division of Merck KGaA, Darmstadt, Germany, announcedtoday the launch of a website dedicated to phenylketonuria (PKU), a rareinborn metabolic disorder. Developed in collaboration with healthcareprofessionals and dieticians, the website aims to provide patients livingoutside of the United States [1], with a reliable and extensive source ofinformation on the disease and its management, including practical tips foreveryday life.

"After the launch in Europe of Kuvan(R), the first pharmaceuticaltreatment option for PKU, Merck Serono is pleased to provide further supportto patients and their families with a new website", said Roberto Gradnik,Executive Vice President, Commercial Europe at Merck Serono. "The websiteprovides clear information addressing the different needs of anyone affectedby this disease, whether patients, families with children suffering from PKU,or patients seeking to start a family."

Over time, the website will be enriched with new tools and additionallanguages. The website is currently available in English and accessible via:http://www.pku.com/en. French, German, Italian and Spanish versions areexpected to be available by the end of 2009, while versions in otherlanguages are planned for 2010.

PKU is an inherited disorder whereby the body fails to break down anessential amino acid called Phenylalanine (Phe), which can be found inprotein-rich food. In patients suffering from PKU, a long lasting excesslevel of Phe in the blood may lead to irreversible neurological disorders inchildren, and cognitive deficits and psychiatric disorders in adults. Atpresent, the management of PKU consists of lifelong dietary restrictionslimiting the Phe intake, often combined with food supplements or substitutes.Used with a restricted Phe diet, Kuvan(R) has been shown to help controlblood levels of Phe in patients suffering from PKU.

About phenylketonuria (PKU)

PKU, a genetic disorder affecting approximately 50,000diagnosed patients in the developed world, is caused by a deficiency of theenzyme phenylalanine hydroxylase (PAH). PAH is required for the metabolism ofphenylalanine (Phe), an essential amino acid found in all protein-containingfoods. If the active enzyme is not present in sufficient quantities, Pheaccumulates to abnormally high levels in the blood and brain, resulting in avariety of complications including severe mental retardation and braindamage, mental illness, seizures and tremors, and cognitive problems. As aresult of global newborn screening efforts implemented in the 1960s and early1970s, virtually all PKU patients in developed countries are diagnosed atbirth.

About Kuvan(R)

Developed by Merck Serono and BioMarin Pharmaceutical Inc.(Nasdaq and SWX: BMRN), Kuvan (sapropterin dihydrochloride), is an oraltherapeutic and the first treatment indicated in Europe for the treatment ofhyperphenylalaninemia (HPA) due to phenylketonuria (PKU) in patients over theage of 4; or due to tetrahydrobiopterin (BH4) deficiency. Kuvan is thesynthetic form of 6R-BH4, a naturally occurring enzyme cofactor that works inconjunction with the enzyme phenylalanine hydroxylase (PAH) to metabolizephenylalanine (Phe). Clinical data show that Kuvan produces significantreductions in blood Phe levels in the subset of patients who areBH4-responsive.

Most common side effects reported with the use of Kuvaninclude headache, runny nose, diarrhea, vomiting, sore throat, cough,abdominal pain, stuffy nose and low levels of phenylalanine in the blood.

Kuvan is approved in 32 countries, including member states ofthe European Union and the USA. Under the terms of the agreement withBioMarin, Merck Serono has exclusive rights to market Kuvan in allterritories outside the USA, Canada and Japan.

About Merck Serono

Merck Serono is the division for innovative prescriptionpharmaceuticals of Merck KGaA, Darmstadt, Germany, a global pharmaceuticaland chemical company. Headquartered in Geneva, Switzerland, Merck Seronodiscovers, develops, manufactures and markets innovative small molecules andbiopharmaceuticals to help patients with unmet medical needs. In the UnitedStates and Canada, EMD Serono operates through separately incorporatedaffiliates.

Merck Serono has leading brands serving patients with cancer (Erbitux(R),cetuximab), multiple sclerosis (Rebif(R), interferon beta-1a), infertility(Gonal-f(R), follitropin alpha), endocrine and metabolic disorders (Saizen(R)and Serostim(R), somatropin), (Kuvan(R), sapropterin dihydrochloride) as wellas cardiometabolic diseases (Glucophage(R), metformin), (Concor(R),bisoprolol), (Euthyrox(R), levothyroxine). Not all products are available inall markets.

With an annual R&D expenditure of around EUR 1bn, Merck Seronois committed to growing its business in specialist-focused therapeutic areasincluding neurodegenerative diseases, oncology, fertility and endocrinology,as well as new areas potentially arising out of research and development inautoimmune and inflammatory diseases.

About Merck

Merck is a global pharmaceutical and chemical company withtotal revenues of EUR 7.6 billion in 2008, a history that began in 1668, anda future shaped by approximately 33,000 employees in 60 countries. Itssuccess is characterized by innovations from entrepreneurial employees.Merck's operating activities come under the umbrella of Merck KGaA, in whichthe Merck family holds an approximately 70% interest and free shareholdersown the remaining approximately 30%. In 1917 the U.S. subsidiary Merck & Co.was expropriated and has been an independent company ever since.

For more information, please visit http://www.merckserono.com orhttp://www.merck.de

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[1] The website http://www.pku.com is already available to PKU patientsand their families living in the US and is managed by BioMarin, MerckSerono's development partner.