Oxford BioMedica says new data presented from two clinical studies indicate "ground-breaking" long-term sustained and dose-dependent gene expression with its LentiVector gene therapy delivery platform.
A Phase I/II study of its Parkinson's disease gene therapy OXB-101 (ProSavin), which transfers three genes for dopamine synthesis, previously showed a favourable safety profile and a statistically significant improvement in motor function at six and 12 months post-treatment in patients with advanced forms of the disease.
But the most recent follow-up data showed that the majority of patients continued to experience this improvement in motor function over the four years following treatment, the firm said, highlighting its long-term efficacy. The company also noted that it has since developed OXB-102, a more potent version of OXB-101, which should be tested in a Phase I/II study later this year.
Elsewhere, an oral presentation on wet AMD therapy RetinoStat delivered at the Association for Research in Vision and Ophthalmology conference showed that gene expression was dose-dependent and continued without significant decline for more than four years.
RetinoStat is designed to deliver two anti-angiogenic genes - endostatin and angiostatin - straight to the retina via LentiVector gene delivery technology, and thereby preserve and even improve vision through blocking the formation of new blood vessels.
"We are very encouraged by the demonstration of long term expression and clinical benefit in patients indicated by the four-year follow-up data from these two clinical studies," said John Dawson, Oxford BioMedica's chief executive.
"We believe this is the first time gene therapy products have been directly measured in the eye and the longevity in both expression and efficacy to date reinforces the benefits of the company's pioneering LentiVector gene delivery platform in the treatment of chronic conditions."