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June 28, 2007

European Union CHMP Recommends Approval of New Formulation of Multiple Sclerosis Treatment Rebif® (interferon beta-1a)

• New formulation of Rebif® designed to improve tolerability and immunogenicity profiles

Darmstadt, June 28, 2007 – Merck KGaA announced today that the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMEA) has issued a positive opinion recommending marketing authorization of a new formulation of Rebif® (interferon beta-1a) for the treatment of relapsing multiple sclerosis (MS). The new formulation of Rebif® was developed by the Merck division to increase treatment benefit by improving injection tolerability and reducing immunogenicity.

“The CHMP recommendation for the new formulation of Rebif® is encouraging news for patients with multiple sclerosis in Europe,” said Anthony Coombs, Head of the Global Therapeutic Area Neurology at Merck Serono. “While Rebif® is well established in the treatment of multiple sclerosis, this new formulation demonstrates our commitment to the further development of products that enhance the convenience and tolerability of treatments for patients with multiple sclerosis.”

The CHMP reviews drug applications for all 27 countries in the European Union1 as well as Iceland and Norway. The CHMP recommendation will now be considered by

1 Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, United Kingdom

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the European Commission, which will deliver its final decision on the granting of the marketing authorization.

Rebif®, which was originally approved in Europe in 1998, has been proven effective on the following three key measures of treatment effectiveness: MRI lesion area and activity, relapse rates, and disability progression. The safety and efficacy of Rebif® are supported by a robust long-term clinical development program including comparative studies and 13 years of patient experience from around the world.

“Merck Serono’s efforts over the years to continuously provide enhanced therapeutic solutions for patients with multiple sclerosis are commendable,” said Professor Per Soelberg Sørensen, from the Danish MS Research Center, Copenhagen University Hospital, Rigshospitalet. “Clinical trial data show that the new formulation of Rebif offers promising improvements, which could translate into additional benefits to the patient."

One-year (48-week) data from an ongoing two-year (96-week) Phase III study of the new formulation of Rebif® were presented at the 17th Meeting of the European Neurological Society (ENS), in Rhodes, Greece2. The data showed that the rate of injection-site reactions in patients with MS who received the new formulation of Rebif® over one year was three times lower when compared with historical data from previous trials. The data also showed that 13.9% of patients treated with the new formulation of Rebif® had neutralizing antibodies after one year treatment. The results at one year showed that patients who tested positive for neutralizing antibodies at both the 24 and 48-week time points represented 2.5% of the patients. The most frequent side effect was flu-like syndrome, which is typical of interferon therapy. Flu-like syndrome tends to be most prominent at the initiation of therapy, is relatively easy to treat and decreases in frequency with continued treatment.

2 Rebif® New Formulation (RNF; interferon beta-1a): 1-year results of a phase IIIb study in patients with relapsing forms of multiple sclerosis - P. Sørensen, O. Barbarash, F. Casset-Semanaz, G. Giovannoni, J. King, L. Metz, G. Pardo, J. Simsarian, B. Stubinski on behalf of the RNF Study Group

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The new formulation of Rebif® has been developed in the same strengths and pharmaceutical forms as currently registered, i.e. 8.8, 22 and 44 mcg, as a solution for injection in pre-filled syringes. This new formulation originates from an innovative approach, using state-of-the-art technologies. It is the latest of many product developments from Merck Serono to continuously enhance the convenience and tolerability of Rebif®. Other enhancements have included the Rebiject II auto-injector to facilitate injections; a 29 gauge-5 bevel needle pre-filled syringe, the thinnest needle in a ready-to-use pre-filled syringe for the treatment of MS; and a titration pack designed to make starting on Rebif® therapy easier and more convenient.

About Rebif® Rebif® (interferon beta-1a) is a disease-modifying drug used to treat relapsing forms of multiple sclerosis (MS) and is similar to the interferon beta protein produced by the human body. Interferon helps modulate the body’s immune system, fight disease and reduce inflammation. Rebif®, which was approved in Europe in 1998 and in the US in 2002, is registered in more than 80 countries worldwide. In the United States, Rebif® is co-marketed by EMD Serono, Inc. (the US affiliate of Merck Serono) and Pfizer Inc. Rebif® has been proven to delay the progression of disability, reduce the frequency of relapses and reduce MRI lesion activity and area3. Rebif® is not approved for treatment of chronic progressive MS. Rebif® is available in a 22 mcg and 44 mcg ready-to-use pre-filled syringe and a titration pack, and can be stored at room temperature for up to 30 days if a refrigerator is not available. Most commonly reported side effects are injection site disorders, flu-like symptoms, elevation of liver enzymes and blood cell abnormalities. Patients, especially those with depression, seizure disorders, or liver problems, should discuss treatment with Rebif® with their doctors.

About Merck Serono and multiple sclerosis Merck Serono is a leader in multiple sclerosis (MS) with Rebif® (interferon beta-1a), a disease-modifying drug used to treat relapsing forms of MS, which is registered in more than 80 countries worldwide. In addition to Rebif®, the Company also offers a second therapy within its US portfolio of MS therapies: Novantrone® ( for injection concentrate) for worsening forms of MS. Full prescribing information for these products can be obtained by contacting the Company or visiting its website. Additional therapeutic options are currently under development at Merck Serono, including oral , currently in Phase III and potentially the first oral therapy for MS, as well as several products in early stage development including: osteopontin, an MMP-12 inhibitor, a JNK inhibitor and interferon beta:Fc. Merck Serono also is taking a leading role in developing an understanding of the role of genetics in MS, with a whole genome scan currently underway.

About multiple sclerosis Multiple sclerosis (MS) is a chronic, inflammatory condition of the nervous system and is the most common, non-traumatic, neurological disease in young adults. The World Health Organization estimates that up to 2.5 million people suffer from MS worldwide. While symptoms can vary, the most common symptoms of MS include blurred vision, numbness or tingling in the limbs and problems with strength and coordination. The relapsing forms of MS are the most common.

3 The exact correlation between MRI findings and the current or future clinical status of patients, including disability progression, is unknown.

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Merck is a global pharmaceutical and chemical company with sales of EUR 6.3 billion in 2006, a history that began in 1668, and a future shaped by 35,091 employees in 62 countries. Its success is characterized by innovations from entrepreneurial employees. Merck's operating activities come under the umbrella of Merck KGaA, in which the holds an approximately 70% interest and free shareholders own the remaining approximately 30%. In 1917 the U.S. subsidiary Merck & Co. was expropriated and has been an independent company ever since.

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