Testing With Procleix® West Nile Virus Assay Initiated on Procleix® TIGRIS® System Under IND

EMERYVILLE, Calif. and SAN DIEGO -- Chiron and Gen-Probe announced that testing with the Procleix® West Nile Virus (WNV) Assay has been initiated under an investigational protocol on the Procleix® TIGRIS® System. The high-throughput, fully automated nucleic acid testing (NAT) system, developed by Gen-Probe, is designed to allow blood centers to test individual blood samples with greater operator efficiency and is being introduced into blood testing centers under IND in regions with the highest prevalence of WNV. The Procleix WNV Assay, which is labeled For Investigational Use Only, has detected 137 WNV-infected donations since May.

"We are pleased that we've been able to meet the needs of our customers by accelerating the availability of the Procleix® TIGRIS® System under IND," said Andrew Heaton, MD, vice president and chief medical officer, Chiron Blood Testing. "The Procleix TIGRIS system is the first fully automated NAT system available for blood screening, and its use with the Procleix WNV Assay will allow for maximum sensitivity by enabling individual donor testing and would bring a new level of quality assurance in detecting potential transfusion-transmitted viruses like WNV."

"Our TIGRIS System offers blood centers revolutionary levels of automation, throughput and process control," said Jim Godsey, PhD, executive vice president of development, Gen-Probe. "These attributes are especially important when testing of individual donor samples is warranted to safeguard the nation's blood supply from viruses such as West Nile that are infectious even at very low copy levels."

Blood centers using the Procleix WNV Assay and experiencing a large number of WNV-positive donations have developed algorithms to determine when testing should be moved from pools of 16 to individual donor testing, which offers the best opportunity to detect the presence of the virus. Testing with the Procleix WNV Assay on the Procleix TIGRIS System is planned for epidemic areas at target sites in Arizona, California, Colorado, Florida and Oklahoma to improve the efficiency of high-volume testing.

In addition, a pivotal clinical trial for the Procleix WNV Assay is currently being conducted at five U.S. blood centers to confirm the Procleix WNV Assay's sensitivity, specificity and reproducibility on a semi-automated instrumentation platform, with an expected filing of this data in the first quarter of 2005. The Procleix TIGRIS System data for the Procleix WNV Assay is also expected to be submitted at that time.

Separately, a clinical trial for the Procleix® Ultrio Assay on the Procleix TIGRIS® System started in February 2004. The Procleix Ultrio Assay is specifically designed for the simultaneous detection of human immunodeficiency virus 1 (HIV-1), hepatitis C virus (HCV) and hepatitis B virus (HBV) in donated blood, plasma, organs and tissues. Clinical trials for the Procleix TIGRIS System have been completed, with FDA submissions for the TIGRIS System for blood screening and for the Ultrio assay planned for later in 2004.

About West Nile Virus

West Nile virus (WNV) is a mosquito-borne virus associated with a human form of the disease, with effects ranging from mild, flu-like symptoms to severe neurological disease. The first confirmed U.S. death resulting from transmission through donated blood was reported in 2002. In the fall of 2002, the U.S. Food and Drug Administration (FDA)challenged industry to develop a test for direct detection of WNV in donated blood by the summer of 2003. Within nine months, Gen-Probe and Chiron had developed the Procleix WNV Assay and brought it to market under an IND. According to the U.S. Centers for Disease Control and Prevention (CDC), 843 human cases of WNV infection have been reported for the current mosquito season as of August 24, 2004.

About Procleix® Assays and Systems

Procleix Assays and Systems incorporate state-of-the-art amplified NAT technology to detect viral RNA and DNA in donated blood and plasma during the very early stages of infection, when those infectious agents are present but cannot be detected by immunodiagnostic tests. The Procleix® HIV-1/HCV Assay, developed in collaboration with Gen-Probe Incorporated, has been commercially available in Europe since 1999 and also bears the CE Mark. The Procleix HIV-1/HCV Assay is approved for use in the United States, the European Union, Australia and major markets in Asia. The Procleix® Ultrio Assay for the simultaneous detection of HIV-1, HCV and HBV has been commercially available in Europe since early 2004.

Source: Chiron