Merck Serono: Regulatory Update on Cladribine Tablets

GENEVA, Switzerland, June 22, 2011 -

• Following recent feedback from FDA
  and previous feedback from EMAMerck
  Serono has decided to no longer
  pursuethe global approval process
  of Cladribine Tablets
• Merck Serono willfocus resources on
  other projects bringingbenefit
  to patients with multiple sclerosis
• The benefit/risk profile of Cladribine
  Tablets is unchanged - Ongoing clinical trials will
  continue
• One-time charge of EUR 20 million to be
  recorded in the second quarter

Merck Serono, a division of Merck KGaA, Darmstadt, Germany,
announced today that, following feedback from regulatory
authorities, the Company has decided to no longer pursue the global
approval process of Cladribine Tablets for the treatment of
relapsing-remitting multiple sclerosis (MS). Based on discussions
with the U.S. Food and Drug Administration (FDA) at the
end-of-review meeting for the Cladribine Tablets new drug
application, Merck Serono believes that data from ongoing clinical
trials are very unlikely to address the FDA requirements and will
not provide a basis for approval. Overall the FDA feedback was
consistent with the feedback previously received from the European
Medicines Agency (EMA). Attempting to fulfill the FDA and the EMA
requirements would necessitate the initiation of a new clinical
trial program which would take several years to complete.

“Considering the time it would take to complete a new clinical
trial program and the significant risk that even a new program
would not result in data sufficient for Cladribine Tablets’
approval, and taking into account the changing competitive
landscape, we have decided to not pursue further the worldwide
approval process of Cladribine Tablets and to focus resources on
other projects bringing benefit to patients with multiple
sclerosis,” said Dr. Stefan Oschmann, President of Merck Serono.
“We will continue our research and development activities and will
actively pursue in-licensing opportunities to further strengthen
our pipeline in multiple sclerosis, and we will also continue our
product enhancement, educational and patient support activities
around Rebif^®, to address relevant medical needs for
patients with this devastating disease.”

“We are extremely grateful for the strong support we have
received from patients and from physicians during the whole
clinical development of Cladribine Tablets,” said
Dr. Bernhard Kirschbaum, Merck Serono’s Head of Research and
Development. “We intend to complete the core 96-week duration of
the ongoing clinical trials with Cladribine Tablets in order to
provide study participants with the opportunity to continue the
trials and to add knowledge for the scientific community.”

Merck Serono’s decision is not based on a change of the
benefit/risk profile of Cladribine Tablets, which remains the same.
Merck Serono intends to complete the core 96-week treatment period
of the CLARITY^[1] EXTENSION,
ORACLE MS^[2] and
ONWARD^[3] clinical trials. Merck
Serono also intends to proceed with the ongoing
PREMIERE^[4] registry which follows
patients who have participated in Cladribine Tablets studies. The
Company is in the process of informing regulatory agencies and work
closely with them to ensure appropriate follow-up of patients. The
Company is also in the process of informing investigators and
providing them instructions for the next steps of the studies.
Patients involved in studies who have questions should contact
their study investigator.

Merck Serono intends to withdraw applications from regulatory
review in the limited number of countries where procedures are
ongoing. In Australia and Russia, where Cladribine Tablets are
approved and available under the trade name Movectro^®,
Merck Serono intends to withdraw the product from the market and
will discuss the timelines and other details with the local
regulatory agencies to determine the best solutions for patients
currently on Movectro^® therapy.

The decisions on Cladribine Tablets announced today will result
in a one-time charge of EUR 20 million which will be recorded in
the second quarter financial statements.

^[1] CLARITY: CLAdRIbine Tablets
treating MS orallY

^[2] ORACLE MS: ORAl CLadribine
in Early MS

^[3] ONWARD: Oral Cladribine
added oN to interferon beta-1a in patients With Active Relapsing
Disease

^[4] PREMIERE: PRospective
observational long-term safEty registry of Multiple sclerosis
patIEnts who have participated in CladRibinE clinical trials

About Cladribine Tablets

Merck Serono’s oral formulation of cladribine (Cladribine
Tablets) is an investigational treatment for patients with
relapsing forms of 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.
Cladribine Tablets were approved in Russia in July 2010 and in
Australia in September 2010 as a treatment of relapsing-remitting
MS.

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.

- The PREMIERE (PRospective observational long-term safEty
registry of Multiple sclerosis patIEnts who have participated in
CladRibinE clinical trials) registry: a long-term observational
safety registry of patients who have participated in Cladribine
Tablets clinical trials, designed to support the evaluation of the
long-term safety of Cladribine Tablets in MS.

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 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®, cetuximab), multiple sclerosis (Rebif®, interferon
beta-1a), infertility (Gonal-f®, follitropin alfa), endocrine and
metabolic disorders (Saizen® and Serostim®, somatropin), (Kuvan®,
sapropterin dihydrochloride), (Egrifta™, tesamorelin), as well as
cardiometabolic diseases (Glucophage®, metformin), (Concor®,
bisoprolol), (Euthyrox®, levothyroxine). Not all products are
available in all markets.

With an annual R&D expenditure of over € 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 € 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. - Genf, 9 Chemin des Mines, 1202 Genf, Schweiz, Media Relations, Tel: +41-22-414-36-00