British Bio-technology Group plc announced Monday that it hasstarted Phase II clinical trials on its immunotherapeutic p24-VLP for treating HIV infection.
These trials, the first of which began last week in Sydney,Australia, are being conducted on upward of 300 patients withadvanced HIV infection. All patients in the study, which willalso take place at centers in Melbourne, London and Antwerp,will have CD4 counts of less than 350 per cubic millimeter andmay already be taking some form of retroviral therapy such asAZT, ddI or ddC.
Phase II trials in asymptomatic HIV patients have been underway since December in Europe. The trials are designed toestablish a safe and immunologically active dose of thecompound, which is a genetically engineered version of HIV'score protein p24.
The compound consists of virus-like particles (VLPs) that arespherical, subcellular particles formed by self-assembling yeastprotein, TY, spliced to the p24 antigen. Each spherical particlecan contain up to 300 copies of the spliced molecule, which aredisplayed on the surface of the VLP, making it potentially veryimmunogenic.
The hope is to prevent or slow the progression of disease inHIV-positive patients by stimulating immunity to the core HIVprotein.
It's known, for instance, that during the progression of thedisease from ARC (AIDS-related complex) to full-blown AIDS,"the rate of fall of p24 antibody correlates with the rate ofprogression of HIV," explained Andrew Miller, director ofclinical research for the Oxford, England, company. "Thisindicates that there's a high cellular immunity to p24, andthat's basically the hypothesis we're testing," Miller said.
Also, the National Institute of Allergy and Infectious Diseases(NIAID) of the National Institutes of Health has recommendedBritish Bio-technology's (BBIOY) agent p24-VLP for evaluationin U.S. trials. Those protocols are being drawn up now, Millertold BioWorld.
-- Jennifer Van Brunt Senior Editor
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