Merck Serono and Ablynx to Equally Contribute to Discover and Develop Nanobodies(R) Against two Targets in Oncology and Immunology and Equally Share the Resulting Profits

GENEVA, SWITZERLAND | September 4, 2008 | Merck Serono, a division of Merck KGaA, Darmstadt, Germany, today announced that it has entered into an agreement with Ablynx (Euronext Brussels: ABLX), to co-discover and co-develop Nanobodies(R) against two targets in oncology and immunology. The agreement includes an upfront cash payment to Ablynx of EUR10 million.

Nanobodies(R) are a new class of therapeutic proteins that contain the unique structural and functional properties of naturally-occurring single domain antibodies. The partners will collaborate to research and develop Nanobody(R)-based therapeutics against two disease targets exploiting some of the key benefits Nanobodies(R) have over conventional antibodies and other fragments.

Under the terms of the agreement, both companies will equally share all research and development costs. Should Ablynx contribute equally to each program, it will be eligible to receive fifty percent of the resulting profits. In addition, Ablynx will have an option to opt-out partly or fully during the research and development programs, in which case the company would be eligible to receive either a reduced profit share, in the case of a partial opt-out, or milestones and royalties on potential sales, in the case of a full opt-out. Total development and commercial milestones, depending on the point of opt-out by Ablynx, could reach up to EUR325 million should a product be approved in multiple indications in all major markets.

"This collaboration reinforces our commitment to deliver innovative treatments in areas of high unmet medical needs," said Dr Bernhard Kirschbaum, Executive Vice President Research of Merck Serono. "We believe that Nanobodies(R) have the potential to provide innovative drugs combining the best features of monoclonal antibodies and small molecules, and we look forward to working with Ablynx."

"We are very pleased to enter into this partnership with Merck Serono, a recognized global leader in the treatment of oncology and immunology therapies. This type of risk and reward sharing collaboration underlines Ablynx’s maturing capabilities and collaboration strategy, whereby we can leverage on the resources and expertise of our partners to advance Nanobodies(R) more quickly into the clinic while retaining an equal share of the value created," commented Dr Edwin Moses, CEO and Chairman of Ablynx.

About Ablynx [Euronext Brussels: ABLX] – http://www.ablynx.com

Founded in 2001 in Ghent, Belgium, Ablynx is a biopharmaceutical company focused on the discovery and development of Nanobodies(R), a novel class of therapeutic proteins based on single-domain antibody fragments, for a range of serious and life-threatening human diseases. The Company currently has over 180 employees. Ablynx completed a successful IPO on Euronext Brussels [ABLX] on 7 November 2007.

Ablynx is developing a portfolio of Nanobody(R)-based therapeutic programmes in a number of major disease areas, including inflammation, thrombosis, oncology and Alzheimer’s disease. Nanobodies(R) have been generated against more than 100 different disease targets. Efficacy data has been obtained in 20 in vivo models for Nanobodies(R) against a range of different targets. Its lead programme, ALX-0081, a novel anti-thrombotic is in a multi-dose Phase 1b study in patients. ALX-0681, also a novel anti-thrombotic, is in advanced preclinical development.

Ablynx has an extensive patent position in the field of Nanobodies(R) for healthcare applications. It has exclusive and worldwide rights to more than 50 families of granted patents and pending patent applications, including the Hamers patents covering the basic structure, composition, preparation and uses of Nanobodies(R).

Ablynx has ongoing research collaborations and significant partnerships with some of the major pharmaceutical companies, including Boehringer Ingelheim, Wyeth Pharmaceuticals and Novartis. Ablynx is building a diverse and broad portfolio of therapeutic Nanobodies(R) through these collaborations as well as through its own internal discovery programmes. The Company dedicates 70% of its R&D staff to rapidly build its internal portfolio of Nanobodies(R) and has only partnered less than 2% of those targets accessible to Nanobodies(R). Ablynx announced final Phase I data from its lead programme, an anti-thrombotic (ALX-0081) in December 2007 and another programme, which is partnered, is in advanced preclinical development.

Nanobody(R) is a registered trademark of Ablynx NV.

About Merck Serono

Merck Serono is the division for innovative prescription pharmaceuticals of Merck, a global pharmaceutical and chemical group. Headquartered in Geneva, Switzerland, Merck Serono discovers, develops, manufactures and markets innovative small molecules and biopharmaceuticals to help patients with unmet medical needs. Its North American business operates in the United States and Canada as EMD Serono.

Merck Serono has leading brands serving patients with cancer (Erbitux(R)), multiple sclerosis (Rebif(R)), infertility (Gonal-f(R)), endocrine and cardiometabolic disorders (Glucophage(R), Concor(R), Saizen(R), Serostim(R)), as well as psoriasis (Raptiva(R)).

With an annual R&D expenditure of around EUR1billion, 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 EUR7.1 billion in 2007, a history that began in 1668, and a future shaped by 31,946 employees in 60 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 http://www.merckserono.net or http://www.merck.de

SOURCE: Merck Serono International SA