Study of Genotypic Resistance Testing is Starting Soon-

Through this study individuals should be able to accessfree genotypic testing; the purpose of the study is gain FDA approval byproving that genotypic test results can improve treatment decision makingby selecting drugs individuals are more sensitive to and thereby reduceviral loads more than without genotypic resistance testing

VGI Launches Vigilance II - A 30,000 Patient, Cost Recovery,Open Label, HIV Genotyping Study

PRNewswire - Wednesday May 19, 1999

------------------------------------------------------------------------

Visible Genetics Inc. announced today, following FDA protocolreview, that it will proceed under its December 1998 Investigational DeviceExemption (IDE) with Vigilance II, a US based open label, cost recoveryHIV Genotyping study. Vigilance II will use VGI's TruGene(TM) HIV-1 Assaykit, OpenGene(TM) DNA sequencing system, and GeneObjects(TM) software. VGItests and kits will be reimbursable through third party, private and publicpayors on a cost recovery basis. The study has an enrollment target of 30,000patients and will create the first large-scale research database of HIVresistance profiles with clinical outcomes. The database will consist ofresistance profiles for up to 30,000 enrolled patients under strict patientconfidentiality, including drug history, drugs selected as a result of genotyping,and viral loads at eight weeks and sixteen weeks after genotype directeddrug selection. The database will be updated on a regular basis and willbe made available to scientists, physicians and patients via the Internet.

"The infrastructure is being put in place for theVigilance II study, and scheduled to be fully operational in the next threeto four months, at which time we can begin active patient enrollment,"said Dr. Gill Morgan, Director of Regulatory Affairs for VGI. "We haveseen unexpectedly strong support for this large-scale open label projectfrom providers, payors, as well as patients, and we are excited about thepotential for the resistance database," she added. Dr. Thomas C. Merigan,Becker Professor of Medicine and Director Center for AIDS Research, StanfordUniversity, will serve as the principal investigator, and a panel of nineprominent HIV investigators have agreed to be on the advisory panel. Thestudy will be open to an unlimited number of clinical sites and will haveapproximately 25 testing sites throughout the U.S.

"The existing prospective data (Viradapt and GARTstudies), as well as the scientific literature, lead us to believe thatcurrently 70% or more of the HIV drug resistance in the US will be basedon simple sets of mutations," said Dr. Merigan. "However, newdrugs and wide-spread use of protease inhibitors have already produced complexinteractions between groups of mutations and drugs that we have little orno hope of understanding without strong clinical data. This high quality,real-time clinical database with 30,000 or more data entries is our besthope of keeping up with the virus. The prevalence and distribution of resistancepatterns and the relationship between these patterns and success or failureof the drugs all in one place may be of enormous scientific and clinicalvalue."

Visible Genetics Inc. manufactures and markets high performanceautomated DNA sequencing systems and complete kits for the analysis of geneslinked to disease. The Company's OpenGene(TM) system employs proprietarystratified DNA testing and single-tube, single-step sequencing methods tosignificantly reduce the time and cost involved in identifying clinicallyrelevant genetic information.