Data from Merck Serono's Multiple Sclerosis Portfolio to be Presented at the 62nd Annual Meeting of the American Academy of Neurology

New Data on Established Therapy Rebif(R) and on Investigational Therapy Cladribine Tablets to be Presented at AAN Underscore Merck Serono's Commitment to Multiple Sclerosis Care and Research

GENEVA, March 31, 2010 - Merck Serono, a division of Merck KGaA, Darmstadt, Germany,
today announced that new data from the company's multiple sclerosis (MS)
portfolio of approved and investigational treatments will be presented at the
62nd Annual Meeting of the American Academy of Neurology (AAN) taking place
April 10 to 17, in Toronto, Canada. The data presented will focus on Rebif(R)
(interferon beta-1a), an established therapy for relapsing forms of MS, and
Cladribine Tablets, a potential oral therapy for relapsing forms of MS
currently under regulatory review in a number of countries.

"We have made a commitment as a leading company in this field
to advance the treatment of multiple sclerosis and the underlying science,"
said Bernhard Kirschbaum, Merck Serono's Head of Global Research and
Development. "The data presented at the upcoming AAN meeting will further
contribute to the existing body of knowledge about Rebif(R) and Cladribine
Tablets, as well as to a greater understanding of the disease."

The following abstracts have been accepted for presentation at
the 62nd AAN Annual Meeting:

    Rebif(R) (interferon beta-1a)

    Platform presentations

    - Measures of Early Clinical Activity as Prognostic Factors
      for Long-Term Clinical Outcomes in Relapsing-Remitting Multiple
      Sclerosis (presentation S01.005, Tuesday, April 13, 2010, 2:45 pm EDT)

    - Subcutaneous Interferon beta-1a Treatment and Pregnancy
      Outcomes in Patients with Multiple Sclerosis (presentation S40.005,
      Wednesday, April 14, 2010, 5:15 pm EDT)

    Poster presentations

    - Assessing the Risk of Malignancy in Patients with Multiple
      Sclerosis Receiving Subcutaneous Interferon beta-1a (poster P01.167,
      Tuesday, April 13, 2010, 7:30 am-12:00 pm EDT)

    - Impact of Medication Adherence to Disease-Modifying Drugs on
      Severe Relapse, and Direct and Indirect Costs among Employees with
      Multiple Sclerosis (poster P01.204, Tuesday, April 13, 2010, 7:30 am-
      12:00 pm EDT)

    - Interferon Beta-1a Modulation of B Cells: Implications for
      Relapsing Multiple Sclerosis (poster P04.197, Wednesday, April 14,
      2010, 3:00 pm-7:30 pm EDT)

    Cladribine Tablets

    Platform presentation

    - Analysis of Clinical and Radiological Disease Activity-Free
      Status in Patients with Relapsing-Remitting Multiple Sclerosis (RRMS)
      Treated with Cladribine Tablets, in the Double-Blind, 96-Week CLARITY
      Study (presentation S21.008, Wednesday, April 14, 2010, 3:45 pm EDT)

    Poster presentations

    - Health Resource Utilization in the CLARITY Study (poster
      P01.205, Tuesday, April 13, 2010, 7:30 am-12:00 pm EDT)

    - Consistent Efficacy of Cladribine Tablets across Multiple
      Sclerosis and Patient Characteristics, in the Double-Blind, 96-Week
      CLARITY Study (poster P02.186, Tuesday, April 13, 2010, 3:00 pm-7:30 pm
      EDT)

    - Effects of Cladribine Tablets on Circulating Lymphocyte
      Subsets in the 96-Week CLARITY Study in Relapsing-Remitting Multiple
      Sclerosis (RRMS) (poster P04.219, Wednesday, April 14, 2010, 3:00 pm-
      7:30 pm EDT)

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 alpha), 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 33,000 employees in 61 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

Contact: Benedicte Bogh, +41-22-414-3600