Leiden, The Netherlands, December 13, 2006 - Dutch biotechnology company Crucell N.V. (Euronext, NASDAQ: CRXL; Swiss Exchange: CRX) today announced that the rabies monoclonal antibody product it is currently developing has entered a Phase I clinical study in the United States. Crucell has developed a human monoclonal antibody product, a combination of two monoclonal antibodies for the post-exposure prophylaxis (PEP) of rabies, using its MAbstract® and PER.C6® technology. The pre-clinical evaluation of the antibody product was performed in collaboration with the Rabies Program of the Centers for Disease Control and Prevention (CDC) in Atlanta.