Crucell Announces Excellent Results for Influenza Antibody

Leiden, The Netherlands - Dutch biopharmaceutical company Crucell N.V. (Euronext, NASDAQ: CRXL; Swiss Exchange: CRX) today announced that its monoclonal antibody (mAb) directed against a broad range of influenza virus strains has strongly outperformed the most current anti-influenza drug in preclinical tests.

The latest results were presented yesterday, by Dr Jaap Goudsmit, at IBC’s 19th Annual International Conference on Antibody Engineering in San Diego, USA. The preclinical study compared Crucell’s mAb CR6261 with the anti-influenza drug oseltamivir in terms of their value for flu prevention and treatment.

The flu strains tested included the ’bird flu’ strain H5N1, which, experts fear, has the potential to cause a pandemic, and H1N1, which is similar to the strain responsible for the devastating pandemic in 1918. Dr Goudsmit presented data showing that the mAb CR6261 was 100% successful in preventing infection with H5N1. When given after H5N1 infection, Crucell’s mAb demonstrated the ability to prevent death and cure disease in all cases. The mAb also performed significantly better for the prevention and treatment of H1N1 infection, illustrating the potential use for seasonal applications as well.

This makes it a potentially powerful antibody against a broad range of influenza strains. Fears of a flu pandemic are fuelled by the rising number of flu strains that have mutated in ways that make them resistant to oseltamivir.

Importantly, the study showed that CR6261 provides immediate protection against the influenza virus, suggesting that it will be able to prevent disease spread. In contrast, oseltamivir was less efficacious and in some cases not effective at all.

The advantages of the mAb over oseltamivir may also be important for protecting or treating people at risk of severe illness or death due to seasonal flu. These include the elderly and immune-suppressed individuals.

The characterization of the antibody will be described in the online journal PLoS ONE (www.plos.org) on December 16, 2008.

“An effective treatment of influenza is urgently needed. The limited efficacy of oseltamivir and the rising resistance to this anti-influenza drug are cause for concern. I am very encouraged by these preclinical results indicating that our monoclonal antibody may provide an effective means for disease prevention and cure,” said Jaap Goudsmit, Crucell’s Chief Scientific Officer.

“Although this antibody is still at any early stage of development, these results are very promising and demonstrate the strength of our in-house research and development aimed at bringing innovation to global health,” said Ronald Brus, Crucell’s Chief Executive Officer.

About Crucell
Crucell N.V. (Euronext, NASDAQ: CRXL; Swiss Exchange: CRX) is a global biopharmaceutical company focused on research, development, production and marketing of vaccines, proteins and antibodies that prevent and treat infectious diseases. Its vaccines are sold in public and private markets worldwide. Crucell’s core portfolio includes a vaccine against hepatitis B, a fully-liquid vaccine against five important childhood diseases and a virosome-adjuvanted vaccine against influenza. Crucell also markets travel vaccines, such as the only oral anti-typhoid vaccine, an oral cholera vaccine and the only aluminum-free hepatitis A vaccine on the market. The Company has a broad development pipeline, with several product candidates based on its unique PER.C6® production technology. The Company licenses its PER.C6® technology and other technologies to the biopharmaceutical industry. Important partners and licensees include DSM Biologics, sanofi-aventis, Novartis, Wyeth and Merck & Co. Crucell is headquartered in Leiden, the Netherlands, with subsidiaries in Switzerland, Spain, Portugal, Italy, Sweden, Korea and the US. The Company employs over a 1000 people. For more information, please visit www.crucell.com.

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 International Financial Reporting Standards (IFRS).