lentivirus

On January 10th, the British Medicine and Healthcare Regulatory Agency (MHRA) approved Genethon’s Phase I / II gene therapy clinical trial application in X-linked chronic granulomatous disease (XCGD) to start at Great Ormond Street Hospital in London. Genethon is also seeking approval for this multicenter trial in Germany, Switzerland and France. In total the trial will include 20 patients (5 per site) to be treated and followed up for 2 years.

The recent developments of viral based vectors in design, in biosafety and in accomplishing high transfection efficiency for transgene expression into target cells makes them attractive tool for various gene transfer applications. Several kinds of viruses, including HIV derived Lentivirus vectors (LVs), non-HIV based Retroviruses, Adenoviruses, Adeno-associated viruses, Baculovirus and Herpes simplex viruses have been manipulated for use in gene transfer and gene therapy purposes. Each viral vector system is integrated with a distinctive in built properties that affect its suitability for specific gene therapy purposes. Although LVs offered many unique solutions for advanced gene therapy research and clinical applications, however, several important issues of LVs gene therapy must be overcome before it gains widespread use. Nonetheless, the number of promising gene therapy studies in progress are highly encouraging and outcome from these clinical trials will provide valuable insights particularly for the clinical suitability and safety profile of LVs. This review contain a comprehensive discussion starting with the general background of the field thereafter discussing the salient features of recent developments in viral vector system in general and with special focus on LVs.

Human Immunodeficiency Virus (HIV)-derived lentiviral vectors provide efficient gene transfer in proliferative and quiescent cells and demonstrate stable, high-level transgene expression both in vitro and in vivo. HIV non specifically integrates its DNA into the human genome, with a preference for active genes. However, integration can be problematic because a variation in gene expression between cells, possible gene silencing, and most importantly insertional mutagenesis, that can provoke malignant transformation.

A strategy that combines gene therapy with blood stem cell therapy may be a useful tool for treating a fatal brain disease, French researchers have found. These findings appear in the 6 November 2009 issue of the journal Science, which is published by AAAS, the nonprofit science society.

Oxford, UK – 1 June 2009: Oxford BioMedica (LSE: OXB), a leading gene therapy company, today announces updated results from open-label Phase I/II and II trials of TroVax in metastatic colorectal cancer and metastatic renal cancer. TroVax is Oxford BioMedica’s therapeutic cancer vaccine that targets the 5T4 tumour antigen. Two cross-trial analyses were presented at the 45th Annual Meeting of the American Society of Clinical Oncology (ASCO) in Orlando, Florida. In all trials, TroVax was well tolerated with no serious adverse events attributed to vaccination.

Oxford, UK – 29 April 2009: Oxford BioMedica (LSE: OXB) announced today that it has entered into a new collaboration with sanofi-aventis to develop novel gene-based medicines, utilising the Company’s LentiVector® gene delivery technology, for the treatment of ocular diseases. Oxford BioMedica will receive an upfront payment of US$26 million (£18 million) and committed funding of up to a further US$24 million (£16 million) over three years. In addition, sanofi-aventis has an exclusive option for a worldwide licence to develop and commercialise four ocular products.

Molecular Biology of the Lentivirus

Lentiviruses are a sub-class of retrovirus that are able to infect both dividing and non-dividing cells. Their genome is much more complex than simple retroviruses, containing an additional six genes; tat, rev, vpr, vpu, nef and vif. Like all retroviruses, lentiviruses are enveloped, however they additionally comprise a pre-integration complex surrounded by the capsid shell.

Lentigen is a diversified biologics company focused on the development and commercialization of breakthrough treatments for human disease. Lentiviral vectors (LV), the company's technology platform, are widely recognized by the scientific community as the most efficient method for delivery of genetic sequence information into cells to reprogram their function. The ability to efficiently and stably reprogram mammalian cells has numerous uses in biotechnology and biomedicine, including drug discovery, target validation, biologics manufacturing and cellular therapies.