PRESS RELEASE: New Formulation of Multiple Sclerosis Treatment Rebif(R) Approved in European Union

New Formulation of Multiple Sclerosis Treatment Rebif(R) Approved in European Union

- New Formulation of Rebif(R) Designed to Improve Injection Tolerability

Merck Serono, a division of Merck KGaA, announced today that the European Commission has granted a marketing authorization for a new formulation of Rebif(R) (interferon beta-1a) for the treatment of relapsing multiple sclerosis (MS). The new formulation of Rebif(R) has been developed to increase treatment benefit by improving injection tolerability while targeting an improved immunogenicity profile. This new formulation originates from an innovative approach, using state-of-the-art technologies.

"The European approval of the new formulation of Rebif(R) is an important step in our efforts to continuously provide enhanced therapeutic solutions for patients with MS," said Roberto Gradnik, Head of Merck Serono's Operations for Europe. "We are pleased to bring this enhanced treatment option to patients throughout Europe."

The European Commission decision applies to all 27 countries in the European Union(1), as well as Iceland, Liechtenstein and Norway. Launches of the new formulation of Rebif(R) in the various countries of the European Union will start in September 2007. The new formulation of Rebif(R) will be available 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.

"The European approval of the new formulation of Rebif(R) is good news for patients with MS," said Professor Per Soelberg Sørensen, Danish Multiple Sclerosis Research Center, Department of Neurology, Copenhagen University Hospital. "This new formulation will represent an improvement in the therapy of MS patients being treated with Rebif(R)."

Rebif(R), 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(R) are supported by a robust long-term clinical development program including comparative studies and 13 years of patient experience from around the world.

The new formulation of Rebif(R) is the latest of many product developments from Merck Serono to continuously enhance the convenience and tolerability of Rebif(R). 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(R) therapy easier and more convenient.

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

About Rebif(R)

Rebif(R) (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(R), which was approved in Europe in 1998 and in the US in 2002, is registered in more than 80 countries worldwide. Rebif(R) has been proven to delay the progression of disability, reduce the frequency of relapses and reduce MRI lesion activity and area(1). Rebif(R) is not approved for treatment of chronic progressive MS. Rebif(R) is available in a 22 mcg and 44 mcg ready-to-use pre-filled syringe and a titration pack (8.8 mcg).

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(R) with their doctors.

About Merck Serono and multiple sclerosis

Merck Serono is a leader in multiple sclerosis (MS) with Rebif(R) (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(R), the Company also offers a second therapy within its US portfolio of MS therapies: Novantrone(R) (mitoxantrone 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 cladribine, currently in Phase III and potentially the first oral therapy for MS, as well as several products in early stage development. Merck Serono also is taking a leading role in developing an understanding of the role of genetics in MS.

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.

Forward-looking statements

Some of the statements in this press release are forward looking. Such statements are inherently subject to known and unknown risks, uncertainties and other factors that may cause actual results, performance or achievements of Merck Serono S.A. and affiliates to be materially different from those expected or anticipated in the forward-looking statements. Forward-looking statements are based on Merck Serono's current expectations and assumptions, which may be affected by a number of factors, including those discussed in this press release and more fully described in Serono's Annual Report on Form 20-F filed with the U.S. Securities and Exchange Commission on February 28, 2006. These factors include any failure or delay in Merck Serono's ability to develop new products, any failure to receive anticipated regulatory approvals, any problems in commercializing current products as a result of competition or other factors, our ability to obtain reimbursement coverage for our products, the outcome of any government investigations and litigation. Merck Serono is providing this information as of the date of this press release, and has no responsibility to update the forward-looking statements contained in this press release to reflect events or circumstances occurring after the date of this press release.

About Merck Serono

Merck Serono, the new division for innovative small molecules and biopharmaceuticals of Merck was established following the acquisition of Serono and the integration of its business with the former Merck Ethicals Division. Headquartered in Geneva, Switzerland, Merck Serono discovers, develops, produces and commercializes innovative products to help patients with diseases with unmet needs. Our North American business operates in the United States and Canada under EMD Serono.

Merck Serono has leading brands serving patients with cancer (Erbitux(R)), multiple sclerosis (Rebif(R)), infertility (Gonal-f(R)), metabolic and cardiometabolic disorders (Glucophage(R), Concor(R), Saizen(R), Serostim(R)), as well as psoriasis (Raptiva(R)). With an annual R&D investment of EUR 1bn, we are committed to growing our business in specialist-focused therapeutic areas such as Neurology and Oncology, as well as new therapeutic areas potentially arising out of our research and development in autoimmune and inflammatory diseases.

About Merck

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 Merck family 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.