Merck Serono's Commitment to Advance Multiple Sclerosis Care and Research Underscored by Data to Be Presented at AAN 2011 Meeting

GENEVA, April 8, 2011 - Merck Serono, a division of Merck KGaA, Darmstadt, Germany,
today announced that new data from the company's multiple sclerosis (MS)
portfolio will be presented at the 63rd Annual Meeting of the American
Academy of Neurology (AAN) taking place from April 9 to 16, in Honolulu,
Hawaii. The data presented will focus on Rebif(R) (interferon beta-1a), an
established therapy for relapsing forms of MS, and Cladribine Tablets, an
oral short-course disease-modifying therapy currently approved and available
under the trade name Movectro(R) in Australia and Russia as a treatment of
relapsing-remitting MS and under regulatory review in Canada and other
countries. In the United States, the company received a complete response
letter from the Food and Drug Administration on Cladribine Tablets on
February 28 and has requested an end-of-review meeting to discuss next steps.

"We are committed to providing treatments that meet the
individual needs of people living with multiple sclerosis at the various
stages of the disease," said Dr. Bernhard Kirschbaum, Merck Serono's Head of
Global Research and Development. "The data to be presented at the upcoming
AAN meeting further enhance our understanding of the clinical effects of
Rebif(R) and Cladribine Tablets and underscore our commitment to advance
multiple sclerosis care, research and outcomes."

The following abstracts have been accepted for presentation at
the 63rd AAN Annual Meeting:

Rebif(R) (interferon beta-1a)

Platform presentation

- Magnetic Resonance Imaging Results from a Phase III,
Randomized, Double-Blind, Placebo-Controlled, Multicenter Trial of Two Dosing
Frequencies of Subcutaneous Interferon Beta-1a in Patients with Clinically
Isolated Syndrome (REFLEX*) (presentation S21.006, Wednesday, April 13, 2011,
2:15 PM)

Poster presentations

- Clinical and Magnetic Resonance Imaging Predictors of
Long-Term Outcomes in Patients with Relapsing-Remitting Multiple Sclerosis:
Additional Analyses (poster P05.045, Wednesday, April 13, 2011, 2:00 PM)

- The CoMPaRe Study Comparing the MusiQoL and MSQoL-54
Instruments in Patients with Multiple Sclerosis (MS) Receiving Long-Term
Therapy with Subcutaneous (sc) Interferon (IFN) Beta-1a: Further Assessment
of Construct Validity (poster P06.058, Thursday, April 14, 2011, 7:30 AM)

- Efficacy of Two Dosing Frequencies of Subcutaneous
Interferon Beta-1a on Risk of Conversion to Multiple Sclerosis in Patients
with Clinically Isolated Syndrome: Results of a Phase III, Randomized,
Double-Blind, Placebo-Controlled, Multicenter Trial (REFLEX*) (poster
P07.194, Thursday, April 14, 2011 2:00 PM)

* The formulation used in REFLEX is currently not approved in
the United States

RebiSmart(TM) (electronic device for self-injection of Rebif(R))

Poster presentation

- Final Results from a 12-Week, Phase IIIb Trial To Evaluate
an Electronic Autoinjector in Patients with Relapsing Multiple Sclerosis
(poster P04.194, Wednesday, April 13, 2011, 7:30 AM) (RebiSmart(TM) is
currently not approved in the United States)

Cladribine Tablets

Poster presentations

- Investigating the Relationship Between Cladribine-Mediated
Changes in Lymphocyte Counts and Clinical/Magnetic Resonance Imaging Outcomes
in Patients with Relapsing-Remitting Multiple Sclerosis: Correlation Analyses
from the Double-Blind, 96-week CLARITY Study (poster P02.174, Tuesday, April
12, 2011, 7:30 AM)

- Tolerability Profile of Cladribine Tablets Therapy for
Patients with Relapsing-Remitting Multiple Sclerosis: Factors Contributing to
Treatment Completion in the Double-Blind, 96-Week, Placebo-Controlled CLARITY
Study (poster P03.243, Tuesday, April 12, 2011, 2:00 PM)

- Effects of Cladribine Tablets in Lymphocyte Subtypes:
Insights from the Phase III, 96-Week, Double-Blind CLARITY Study (poster
P03.216, Tuesday, April 12, 2011, 2:00 PM)

- Evaluation of the Treatment Effect of Cladribine Tablets in
the Cohort of Patients Who Had Failed Prior Treatment with Injectable Disease
Modifying Drugs: The CLARITY Relapsing Remitting Multiple Sclerosis Study
(poster P04.197, Wednesday, April 13, 2011, 7:30 AM)

- Safety and Efficacy of Cladribine Tablets for
Relapsing-Remitting Multiple Sclerosis in Patients with High Disease
Activity: Results from the Phase III, 96-Week CLARITY Study (poster P07.195,
Thursday, April 14, 2011, 2:00 PM)

About Merck Serono

Merck Serono is the biopharmaceutical division of Merck KGaA,
Darmstadt, Germany, a global pharmaceutical and chemical company.
Headquartered in Geneva, Switzerland, Merck Serono discovers, develops,
manufactures and markets prescription medicines of both chemical and
biological origin in specialist indications. In the United States and Canada,
EMD Serono operates as a separately incorporated affiliate of Merck Serono.

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), (Egrifta(TM), tesamorelin), 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 over EUR 1bn, 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
rheumatology.

About Merck

Merck is a global pharmaceutical and chemical company with
total revenues of EUR 9.3 billion in 2010, a history that began in 1668, and
a future shaped by more than 40,000 employees in 67 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