Merck Serono and Domain Therapeutics Announce an Agreement to Develop Drugs for Parkinson's Disease

Merck Serono to Develop Domain Therapeutics' mGluR4 Allosteric Modulators

GENEVA, January 17, 2011 - Merck Serono, a division of Merck KGaA, Darmstadt, Germany, today
announced that an exclusive development and licensing agreement with Domain
Therapeutics, Strasbourg, France, was signed to develop metabotropic
glutamate receptor 4 (mGluR4) Positive Allosteric Modulator (PAM) drugs
targeting Parkinson's disease and other neurodegenerative diseases.

Domain Therapeutics will contribute optimized compounds that have been
developed from their proprietary chemical series. Under the terms of the
agreement, the company will receive EUR 2 million in upfront payment and
research funding, and is eligible for up to EUR 132 million in milestones for
the first two products, as well as undisclosed royalties.

"We are pleased to have the opportunity to work with Domain Therapeutics,
which has developed great expertise in the G-Protein Coupled Receptor area,"
said Bernhard Kirschbaum, Executive Vice President for Global Research and
Development at Merck Serono. "This partnership with Domain Therapeutics
reflects our long-term commitment to develop new treatments for
neurodegenerative diseases."

"This agreement is a validation of Domain Therapeutics' business model of
addressing difficult GPCRs and partnering compounds, with a significant deal,
at an early stage of development," said Pascal Neuville, CEO, Domain
Therapeutics. "Merck Serono is known to set very high standards for the
compounds they are licensing and this deal is a demonstration of the quality
of our work. We anticipate that this agreement will enable us to sign further
deals of this kind."

mGluR4 is a glutamate receptor, member of the G-Protein Coupled Receptor
(GPCR) family and is believed to be a potential therapeutic target for
Parkinson's disease. Allosteric modulation of mGluR4 receptors is thought to
exert regulatory activity on glutamate-mediated neurotransmission.

About Domain Therapeutics S.A.

Domain Therapeutics is a biopharmaceutical company located in
Strasbourg, France, dedicated to the discovery and early development of small
molecules targeting G-coupled Protein Receptors (GPCRs), one of the most
important classes of drug targets. Domain Therapeutics discovers allosteric
modulators for GPCRs such as lipidic and peptidic receptors, which are
difficult to address. The company's pipeline is composed of new chemical
entities, ranging from hits to optimized leads for leading indications such
as schizophrenia, Parkinson's disease, and diabetes.

mGluR4 PAMs of Domain Therapeutics were discovered in the
course of the ARAMIS project, in association with Prestwick Chemical Inc and
two academic laboratories of Strasbourg University and supported by a grant
of the French Government (DGCIS), Alsace Region and Strasbourg City area.
ARAMIS was one of the first collaborative projects of Alsace BioValley
competitiveness cluster.

For more information, please visit
www.domaintherapeutics.com

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) 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 7.7 billion in 2009, a history that began in 1668, and
a future shaped by approximately 40,000 (including Merck Millipore) 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