Gen-Probe Incorporated announced results from the initial field evaluation (beta trial) of the Company's TIGRIS System for clinical diagnostic testing. Two applications of the TIGRIS System, a fully automated NAT instrument system, are being developed: one for use in clinical laboratories and the other for use in testing donated blood.

In the field evaluation conducted at the University of Alabama, Birmingham, the TIGRIS System was tested on over 6,500 simulated clinical samples using the Company's APTIMA Combo 2 Assay over an 18-day period. The APTIMA Combo 2 Assay, an amplified NAT test kit for detecting chlamydia and gonorrhea infections was launched in August 2001. The APTIMA Combo 2 Assay can be run manually or on currently available semi-automated test systems. Running the APTIMA Combo 2 Assay on the TIGRIS platform will provide high-volume laboratories with the advantages of full automation and greater throughput. The Company plans to submit an application for marketing of the TIGRIS System for clinical laboratory testing to the Food and Drug Administration (FDA) in 2003.

During the field evaluation, 6,541 tests were loaded onto the automated system and 84% were completed. The vast majority of the incomplete tests were traced to a small number of readily correctable causes: a nonconforming lot of specimen collection tubes, two service errors, and a minor software error. False positive and false negative results were less than one percent for each target organism (Chlamydia trachomatis and Neisseria gonorrhoeae). These results are consistent with the Company's in-house development protocols.

Field evaluations for the TIGRIS System for blood testing using the Procleix HIV-1/HCV Assay for the simultaneous detection of human immunodeficiency virus type 1 (HIV-1) and hepatitis C virus (HCV) are expected to begin by the end of 2002. In collaboration with Chiron Corp., the Company is in advanced development of a triplex assay (to be known as the Procleix Ultrio Assay) that will detect hepatitis B virus (HBV) in addition to HIV-1 and HCV. The Company plans to meet with the FDA in early October to discuss the regulatory path for TIGRIS as it pertains to the FDA's recent interest in individual donor testing (IDT). Based upon the results of this meeting, the Company will then determine whether to pursue an IDT indication on TIGRIS with the current Procleix Assay or to aggressively pursue clinical trials of the Ultrio Assay for blood screening on TIGRIS systems.