Research Update

Oxford Biomedica PLC 26 June 2000 For further information, please contact: Oxford BioMedica plc Professor Alan Kingsman, Chief Executive Tel: +44 (0)1865 783 000 City / Financial Enquiries David Simonson / Melanie Toyne Sewell Tel: +44 (0)207 606 1244 Scientific / Trade Press Enquiries Sue Charles/ Katja Stout, HCC.De Facto Tel: +44 (0)207 496 3300 OXFORD BIOMEDICA ANNOUNCES SIGNIFICANT ADVANCES IN GENE TRANSFER TO THE BRAIN Monday, 26 June 2000 Forum for European Neurosciences, Brighton: Oxford BioMedica announces latest results for high gene transfer efficiency, excellent safety profile and long term gene expression into the brain using lentiviral vectors. Oxford BioMedica presented the Company's latest results on its proprietary LentiVectoR(TM) technology for delivering genes to the brain and other parts of the nervous system at Forum for European Neurosciences 2000 held in Brighton. These new results build on data published in 1999 in the scientific journal 'Gene Therapy', and substantially move the commercial application of LentiVector(TM) forward. BioMedica's LentiVector(TM) system is based on a horse virus called Equine Infectious Anaemia virus (EIAV). The Company has engineered the virus so that it picks up therapeutic genes and delivers them to human cells. The EIAV-based vector has been constructed so that, unlike many other gene therapy vectors, it does not transfer any viral genes to the patient's cells. This, coupled with the fact that EIAV, in its natural state, does not cause disease in man, gives this system one of the best safety profiles in the gene therapy field. The technology is being used initially to develop gene therapy products for Parkinson's disease but it has the potential to treat other diseases such as Alzheimer's disease and to treat spinal injury and nerve degeneration. The Company has developed its production technology to a point where the efficiency of gene transfer is extremely high when the vector is introduced into the brain. Dr. Nick Mazarakis, BioMedica's Head of Neurobiology showed results in Brighton where a marker gene was delivered to more than 105 brain cells using just one microlitre of the LentiVector(TM) preparation. Commenting on these results Dr. Mazarakis said: 'The efficiency and reliability of this system is such that we can contemplate developing a wide range of products for neurological disease. In addition this technology opens the way to use gene transfer to probe the basic functions and mechanisms of the brain in a way that has simply not been possible before.' Dr. Mazarakis' presentation also showed that BioMedica's technology led to very long-term gene expression in the brain. A reporter gene was shown to function for several months with no drop in levels of gene expression and no adverse side effects. This is important for treating chronic diseases such as Parkinson's disease. Furthermore, by engineering the LentiVector's surface molecules BioMedica has been able to deliver genes to different types of neurones in the brain. Commenting on the presentation, BioMedica's Chief Executive, Professor Alan Kingsman said, 'We are pleased to have been invited to present our results at such a prestigious meeting. Our Parkinson's disease product is progressing well and we are initiating new product programmes for other neurological disease and injury. In addition, we believe that the LentiVector(TM) technology will enable us to generate short-term revenue by offering target validation contracts to the pharmaceutical industry in the neurobiology field. We can also use the technology to identify new genes that are mechanistically linked to neurodegenerative diseases. It is a very exciting time to be in this field.' Notes to Editors 1. Oxford BioMedica plc Established in 1995, the Company specialises in the development and application of gene-based therapeutics using advance gene delivery technologies for the treatment of disease in the areas of Oncology, Viral Infection and Neurobiology. Oxford BioMedica plc was floated on the UK Alternative Investment Market of the London Stock Exchange in December 1996. 2. Lentivirus vector systems for gene transfer to the brain In gene therapy, the aim is to deliver a gene and its necessary regulatory elements (the gene construct) to the cell surface, using a vector to mediate the transfer across the cell membrane and, in some cases, into the nucleus. Vector systems based on lentiviruses are now showing great potential. They have similar features to retroviruses in the ease of manipulation, predictable integration and reliable gene expression and regulation. The main advantage over retroviruses is the ability to function in non-dividing cells or cells that are dividing slowly - a feature of many clinically important tissues including the central and peripheral nervous system. In contrast to some other gene delivery systems, BioMedica's retroviral and lentiviral vector systems produce no detectable adverse inflammatory responses. For therapies requiring delivery of genes to brain cells, this is an essential requirement. 3. Types of lentiviruses Lentivirus vectors are constructed from two sources: - primate viruses e.g. human or simian immunodeficiency virus (HIV or SIV) - non-primate viruses e.g. feline and bovine immunodeficiency viruses (FIV and BIV), and one of the most simple, equine infection anaemia virus (EIAV) 4. Move away from HIV-based vectors Most early lentiviral vector development focused on the HIV-1-derived system, as HIV is the most thoroughly characterised of the lentiviruses. However concerns over the use of HIV-based vectors for diseases other than HIV infection are leading to the use of non-primate viruses. 5. Worldwide web This release is also available on the Worldwide Web at http://www.oxfordbiomedica.co.uk
UK 100

Latest directors dealings