Data to be Presented at ENS 2010 Meeting Underscore Merck Serono's Commitment to Advance Multiple Sclerosis Care and Research

GENEVA, June 17, 2010 - Merck Serono, a division of Merck KGaA, Darmstadt, Germany,
today announced that data from the company's multiple sclerosis (MS)
portfolio will be presented at the 20th Meeting of the European Neurological
Society (ENS) taking place from June 19 to 23 in Berlin, Germany. The data
presented will focus on Rebif(R) (interferon beta-1a), an established therapy
for relapsing forms of MS, RebiSmart(TM), an electronic device for
self-injection of Rebif(R) (currently not approved in the US), as well as
Cladribine Tablets, an investigational oral therapy for relapsing-remitting
MS currently under regulatory review in a number of countries.

"Merck Serono has a long-term commitment to patients living
with multiple sclerosis through the development of new therapeutic options,"
said Dr. Bernhard Kirschbaum, Merck Serono's Head of Global Research and
Development. "The data to be presented at the upcoming ENS meeting enhance
our understanding of the clinical effects of Rebif(R) and Cladribine Tablets
and underscore our commitment to advance multiple sclerosis research and to
provide treatments that meet the individual needs of people living with
multiple sclerosis".

The following abstracts have been accepted for presentation at
the 20th ENS Meeting:

Rebif(R) (interferon beta-1a) / RebiSmart(TM)

Platform presentation

- Evaluation of the risk of malignancy in patients with
multiple sclerosis treated with subcutaneous interferon beta-1a (Presentation
044, Monday, June 21, 2010, 15:15-15:30 CET)

Posters

    - Associations between annualized relapse rate and long-term
      exposure to subcutaneous interferon beta-1a in the Prevention of
      Relapses and disability by Interferon beta-1a Subcutaneously in
      Multiple Sclerosis (PRISMS) long-term follow-up study (Poster
      P456, Tuesday, June 22, 2010, 11:30-13:00 CET)

    - Assessment of adherence to subcutaneous interferon beta-1a
      treatment in daily practice among patients with relapsing multiple
      sclerosis using an electronic self-injection device (Poster P580,
      Tuesday, June 22, 2010, 17:30-19:00 CET)

    Cladribine Tablets

    Platform presentation

    - Analysis of clinical and radiological disease activity-free
      status in patients with relapsing-remitting multiple sclerosis
      treated with cladribine tablets, in the double-blind, 96-week CLARITY
      study (Presentation O75, Monday, June 21, 16:00-16:15 CET)

    Poster presentations

    - Consistent efficacy of cladribine tablets across multiple
      sclerosis and patient characteristics, in the double-blind, 96-week
      CLARITY study (Poster P441, Tuesday, June 22, 11:30-13:00 CET

    - Reconstitution of circulating lymphocyte subsets after
      treatment with cladribine tablets in the 96-week CLARITY study in
      relapsing-remitting multiple sclerosis (Poster P442, Tuesday, June 22,
      11:30-13:00 CET)

    - Late stage clinical development plan for cladribine tablets
      in the treatment of multiple sclerosis (Poster P443, Tuesday, June 22,
      11:30-13:00 CET)

    - Evaluation of the long-term safety of cladribine tablets in
      multiple sclerosis: design of PREMIERE, a prospective, observational
      8-year safety registry (P444, Tuesday, June 22, 11:30-13:00 CET)

Clinical aspects of MS

Poster presentation

Physician and patient perspectives in multiple sclerosis: results from
the MS Choices Survey (Poster P236, Monday, June 21, 2010, 11:30-13:00 CET)

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. The efficacy of Rebif(R)
in chronic progressive MS has not been established. Interferons are thought
to help modulate the body's immune system and reduce inflammation. The exact
mechanism is unknown.

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*. Rebif(R) is available in a
22 micrograms and 44 micrograms ready-to-use pre-filled syringe and a
titration pack (8.8 micrograms). Rebif(R) is now available in Germany, UK and
Denmark as well as in Canada in two multidose cartridges [132 micrograms
(three doses of 44 micrograms) and 66 micrograms (three doses of 22
micrograms)] for the use with the RebiSmart(TM) device.

Rebif(R) should be used with caution in patients with a history of
depression, liver disease and seizures. Most commonly reported side effects
are flu-like symptoms, injection site disorders, 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.

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

About Cladribine Tablets

Merck Serono's oral formulation of cladribine (Cladribine
Tablets) is an investigational treatment for patients with
relapsing-remitting multiple sclerosis (MS). Cladribine is a small molecule
that may interfere with the behavior and the proliferation of certain white
blood cells, particularly lymphocytes, which are thought to be involved in
the pathological process of MS. Merck Serono has applied for marketing
approval of Cladribine Tablets in the European Union, the United States and
other locations.

The clinical development program for Cladribine Tablets
includes:

    - The CLARITY (CLAdRIbine Tablets Treating MS OrallY) study
      and its extension: a two-year Phase III placebo-controlled trial
      designed to evaluate the efficacy and safety of Cladribine Tablets
      as a monotherapy in patients with relapsing-remitting MS and the
      CLARITY EXTENSION two-year Phase III study designed to provide
      data on the long-term safety and efficacy of
      extended administration of Cladribine Tablets for up to four
      years.

    - The ORACLE MS (ORAl CLadribine in Early MS) study: a
      two-year Phase III placebo-controlled trial designed to evaluate
      the efficacy and safety of Cladribine Tablets as a monotherapy in
      patients at risk of developing MS (patients who have experienced a
      first clinical event suggestive of MS). This trial was announced in
      September 2008.

    - The ONWARD (Oral Cladribine Added ON To Interferon beta-1a
      in Patients With Active Relapsing Disease) study: a Phase II
      placebo-controlled trial designed primarily to evaluate the safety and
      tolerability of adding Cladribine Tablets treatment to patients with
      relapsing forms of MS, who have experienced breakthrough disease
      while on established interferon-beta therapy. This trial was announced
      in January 2007.

About multiple sclerosis

Multiple sclerosis (MS) is a chronic, inflammatory condition
of the central nervous system and is the most common, non-traumatic,
disabling neurological disease in young adults. It is estimated that
approximately two million people have 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.

About Merck Serono

Merck Serono is the division for innovative prescription
pharmaceuticals of Merck KGaA, Darmstadt, Germany, a global pharmaceutical
and chemical company. Headquartered in Geneva, Switzerland, Merck Serono
discovers, develops, manufactures and markets innovative small molecules and
biopharmaceuticals to help patients with unmet medical needs. In the United
States and Canada, EMD Serono operates through separately incorporated
affiliates.

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

With an annual R&D expenditure of more than EUR 1 billion,
Merck Serono is committed to growing its business in specialist-focused
therapeutic areas including neurodegenerative diseases, oncology, fertility
and endocrinology, as well as new areas potentially arising out of research
and development in autoimmune and inflammatory diseases.

About Merck

Merck is a global pharmaceutical and chemical company with
total revenues of EUR 7.7 billion in 2009, a history that began in 1668, and
a future shaped by approximately 33,600 employees in 64 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.

For more information, please visit www.merckserono.com
or www.merck.de

Merck Serono S.A. - Geneva, 9 Chemin des Mines, 1202 Genève, Suisse, Media relations, Tel: +41-22-414-36-00