Start of Phase II Clinical Study for Rabies Monoclonal Antibody Combination in the Philippines

Leiden, The Netherlands, May 2008 - Dutch biotechnology company Crucell N.V. today announced that its rabies monoclonal antibody combination product has entered a second phase II clinical study in the Philippines. On 31 March 2008 the company announced the start of a first phase II clinical study in the U.S.

At the beginning of the year, Crucell announced a collaboration and commercialization agreement with sanofi pasteur for Crucell’s rabies monoclonal antibody combination product to be used in combination with rabies vaccines for post-exposure prophylaxis against this fatal disease. Crucell received an initial payment of €10 million following the execution of the agreement and will be eligible for milestone payments of up to €66.5 million. The first phase II study, as announced in March 2008, marked an important milestone in the collaboration agreement.

The second phase II clinical trial will be a randomized, single-blind, controlled study in 48 healthy adolescents and children. The study will test the rabies monoclonal antibody combination product in association with sanofi pasteur’s rabies vaccine and will compare it to the human rabies immune globulin, which is currently administered with the vaccine. The main parameters under investigation will be safety, tolerability and (rabies virus) neutralizing activity. This clinical trial aims to generate safety data in children in Asia, complementing the safety data generated in adult volunteers during a phase I trial conducted in India. Jointly, the combined data allows a swift phase III clinical evaluation of the monoclonal antibody combination in individuals exposed to rabies in endemic areas like Asia.

“We are clearly on a fast track with the development of this new rabies treatment”, said Ronald Brus, Crucell’s Chief Executive Officer. “Our rabies antibody combination product is highly suitable to replace the currently used serum-based products. This antibody product can be produced in sufficient quantities to cover public and private sectors needs by the use of our PER.C6® technology. Expanded product availability would clearly help combat the supply restrictions of serum-based immune globulin products. The continued rapid development of our rabies antibody product in combination with sanofi pasteur’s rabies vaccine can therefore considerably reduce the global burden of this fatal disease. ”

Sanofi pasteur is the worldwide market leader in providing biologicals for pre- and post-exposure prophylaxis against rabies. In the last 20 years, over 20 million people in 100 countries have been treated with sanofi pasteur’s rabies products.

Peak sales for Crucell’s rabies monoclonal antibody combination product are expected to exceed US$ 300 million.
Forward-looking statements
This press release contains forward-looking statements that involve inherent risks and uncertainties. We have identified certain important factors that may cause actual results to differ materially from those contained in such forward-looking statements. For information relating to these factors please refer to our Form 20-F, as filed with the U.S. Securities and Exchange Commission on May 7, 2008, and the section entitled “Risk Factors”. The Company prepares its financial statements under generally accepted accounting principles in Europe (IFRS).