AMT to Supply cGMP Manufacturing to Consortium Led by Institut Pasteur for Clinical Development of Gene Therapy for Rare Genetic Disorder in Children

AMT Gains Option to Acquire Commercial Rights to Sanfilippo B Gene Therapy Product

AMSTERDAM, January 10, 2011 - Amsterdam Molecular Therapeutics (Euronext: AMT), a leader in
human gene therapy, announced today that it has entered into an agreement
with Institut Pasteur, Paris, France, and a group of French research
institutes (together the "Consortium") to support clinical development of a
novel gene therapy to treat Sanfilippo B. This rare genetic disease affecting
new-born children leads to progressive neuronal degeneration and death. There
is no approved therapy currently available.

On behalf of the Consortium, Institut Pasteur will lead the
development program and will also sponsor the initial Phase I/II clinical
study of a gene therapy to replace an enzyme (alpha-N-acetylglucosaminidase)
that is missing in brain cells of SanfilippoB patients. This enzyme is
specifically required for the degradation of heparan sulfate
glycosaminoglycans (GAGs), essential carbohydrate molecules used to build
tissue. The accumulation of incompletely degraded GAG molecules triggers a
cascade of pathological events leading to neuronal dysfunction and death.

AMT will manufacture and supply the adeno-associated viral 5
(AAV5) gene therapy product to the Consortium. Thanks to donations collected
during the French Telethon, the French Muscular Dystrophy Association (AFM),
a Consortium member, will fully fund the development program through to
completion of the Phase I/II clinical study, including all AMT manufacturing
costs. The overall manufacturing contract entails payments to AMT of EUR1.8
million. If the Consortium successfully demonstrates proof of concept in the
Phase I/II study, AMT will have an option to acquire full commercial rights
for the program. The Phase I/II clinical study is scheduled to begin before
2013.

"This partnership leverage's AMT's proven expertise in cGMP
manufacturing of gene therapy products and our experience in progressing
these products through clinical development and the regulatory processes
needed for successful commercialization," said Jörn Aldag, CEO of AMT. "In
addition, we will have an option to acquire full commercial rights for the
program on completion of the Phase I/II study, which supports our strategy to
build a pipeline of orphan and ultra-orphan indications."

Muriel Eliaszewicz, Medical Director of Institut Pasteur,
said: "AMT is one of the only companies in the world that has a proven
ability in manufacturing cGMP quality gene therapy products, not only in
batches sufficient for clinical development but also in support of a
potential regulatory approval. We are delighted that we now have the ability
to commence the difficult process of developing a cure for patients with this
very challenging disease."

AMT has a cGMP-licensed, 375 m2 manufacturing facility to
produce its AAV vectors for gene therapy products. This highly specialized
facility is fully validated for commercial production and has a capacity
capable of producing enough material to supply its European and North
American target markets with AMT's lead product Glybera(R), currently under
review at the European Medicines Agency (EMA) for treatment of lipoprotein
lipase deficiency (LPLD) and for the next phases of clinical development of
all other programs currently in the pipeline.

In December 2010, Consortium researchers published preclinical
data on the Sanfilippo B gene therapy in Molecular Therapy, the official
publication of the American Society of Gene and Cell Therapy*. This data
demonstrated safety and efficient spreading of the AAV5 gene vector particles
throughout the brain in models of the disease. The gene vectors also
exhibited long-term viability within the cells and an improvement of
histological and biochemical markers.

AMT to present today at Biotech Showcase in San Francisco

Amsterdam Molecular Therapeutics will present today, Monday,
Jan. 10, 2011, at 2 p.m. Pacific time, at the Biotech Showcase Conference in
San Francisco. Jörn Aldag, chief executive officer, will make a formal
presentation at the conference, which runs parallel to the 28th Annual J.P.
Morgan Healthcare Conference, and takes place at Parc 55 Wyndham San
Francisco - Union Square. The presentation takes places in the Stockton room.

*Molecular Therapy 18, 2041 (December 2010)
|10.1038/mt.2010.265

About the Disease

Sanfilippo B is a rare autosomal recessive lysosomal storage
disease, which manifests in young children. Initial symptoms include a
slowing of development and/or behavioral problems, followed by progressive
intellectual decline resulting in severe dementia and progressive motor
disease. In the final phase of the illness, children become increasingly
immobile and unresponsive, often require wheelchairs, and develop swallowing
difficulties and seizures. The life-span of an affected child does not
usually extend beyond late teens to early twenties. Currently there is no
approved therapy for this disease. The estimated number of new cases of
SanFilippo B syndrome in the European Union is 14 per year.

About Amsterdam Molecular Therapeutics

AMT is a world leader in the development of human gene based
therapies. The company's lead product Glybera(R), a gene therapy for the
treatment of lipoprotein lipase deficiency (LPLD), is currently under review
by the European Medicines Agency (EMA). If approved, Glybera will be the
first gene therapy product to be marketed in Europe. AMT also has a product
pipeline of several gene therapy products in development for hemophilia B,
Duchenne muscular dystrophy, acute intermittent porphyria, and Parkinson's
disease. Using adeno-associated viral (AAV) derived vectors as the delivery
vehicle of choice for therapeutic genes, the company has been able to design
and validate probably the world's first stable and scalable AAV manufacturing
platform. This proprietary platform can be applied to a large number of rare
(orphan) diseases caused by one faulty gene and allows AMT to pursue its
strategy of focusing on this sector of the industry. AMT was founded in 1998
and is based in Amsterdam. Further information can be found at
www.amtbiopharma.com.

About Institut Pasteur

Louis Pasteur created the Institut Pasteur in 1887 as a
private non-profit foundation that rapidly became world-renowned for its
biomedical research. The main aim of the Institut Pasteur is understanding
and preventing diseases throughout the world through excellent scientific and
public health research, teaching and other activities. Together with its
major contribution to a deeper understanding of fundamental aspects of life,
the Institut Pasteur continues to devote a large part of its efforts to
infectious diseases, inherited disorders, neurodegenerative diseases and
certain cancers. Close to 2,600 people work on its main campus in Paris,
which is at the heart of an international network of 32 research institutes
on 5 continents. Over the years, 10 Institut Pasteur researchers have
received the Nobel Prize.

www.pasteur.fr

About the French Muscular Dystrophy Association (AFM)

AFM, a Consortium member, has become a major player in
biomedical research on rare diseases in France and around the world. Thanks
to donations from France's annual Telethon, the AFM is currently funding 36
clinical trials on 30 different genetic diseases: neuromuscular or
neurological diseases, and diseases of the blood, eyes, skin and immune
system.

Certain statements in this press release are "forward-looking statements"
including those that refer to management's plans and expectations for future
operations, prospects and financial condition. Words such as "strategy,"
"expects," "plans," "anticipates," "believes," "will," "continues,"
"estimates," "intends," "projects," "goals," "targets" and other words of
similar meaning are intended to identify such forward-looking statements.
Such statements are based on the current expectations of the management of
AMT only. Undue reliance should not be placed on these statements because, by
their nature, they are subject to known and unknown risks and can be affected
by factors that are beyond the control of AMT. Actual results could differ
materially from current expectations due to a number of factors and
uncertainties affecting AMT's business. AMT expressly disclaims any intent or
obligation to update any forward-looking statements herein except as required
by law.

    For further enquiries:

    Jörn Aldag
    CEO
    AMT
    Tel : +31-20-566-7394
    j.aldag@amtbiopharma.com

    Mike Sinclair
    Partner
    Halsin Partners
    Tel : +44-20-7318-2955
    msinclair@halsin.com

For further enquiries: Jörn Aldag, CEO, AMT, Tel : +31-20-566-7394, j.aldag at amtbiopharma.com; Mike Sinclair, Partner, Halsin Partners, Tel : +44-20-7318-2955, msinclair at halsin.com