Note: Development discontinued

It has been decided that these programs will no longer be continued. Crucell has come to the conclusion that the commercial and market opportunities for its West Nile products are not as attractive as other products in Crucell's pipeline.

Crucell has discovered the first human monoclonal antibody effectively neutralizing the virus in cell culture and that fully protects against West Nile virus in a pre-clinical animal model.

No licensed vaccine or small molecule drug is currently available against this virus. Studies with immune sera and mouse monoclonal antibodies have shown that mice can be protected against a lethal West Nile virus infection by administration of antibody as late as 5 days after infection. Therefore, the National Institutes of Health, USA, are currently conducting a multicenter trial to investigate the use of immune serum derived from human donors for the therapy of West Nile virus infection.

We have shown that our fully human monoclonal antibody, derived from patients who survived West Nile virus infection, effectively neutralized the virus in cell culture and fully protected mice from an otherwise lethal infection.  If successfully developed as a product, the antibody may be applied post-infection in specific cases to prevent the potentially fatal onset of encephalitis.

Crucell has delivered proof of concept for the West Nile Virus Antibody. We are seeking partners for a clinical development program.

Named after the West Nile district of Uganda where the disease was discovered in 1937, West Nile virus infection can lead to mortality in humans and animals by causing a fatal form of encephalitis, or inflammation of the brain. It is estimated that 20% of the people who become infected with West Nile virus will develop West Nile fever. Persons over 50 years of age have the highest risk of developing a severe disease, such as meningitis, an inflammation of the membrane around the brain and the spinal cord, or encephalitis, an inflammation of the brain. Since 1999, West Nile virus has caused disease in more than 16,000 U.S. citizens, leading to 650 deaths.

Continued efforts are being made to find suitable treatments and vaccines to stop this virus. The virus may become a recurring threat in the United States. In 2003 and 2004, a number of West Nile virus cases were reported in Europe.