Oxford BioMedica and Institute of Ophthalmology describe key features of vision-loss product RetinoStat at the 2003 Annual Meeting of the Association for Research in Vision and Ophthalmology (Arvo)
Arvo is the world's biggest forum for eye research and is attended by all principal commercial and scientific players in the field, a total of around 8000 attendees.
In two separate presentations the company and the Institute's Ocular Gene Therapy Group, led by Robin Ali, are showing data that confirm RetinoStat's ability to target accurately the retina using the company's LentiVector system.
In addition, the company's Hypoxia Response Element technology is shown to focus gene expression in those parts of the retina that are local to the pathological changes associated with age-related macular degeneration (AMD) and diabetic retinopathy (DR), the two major causes of vision-loss in the developed world.
These data were generated in industry-standard preclinical models for the two diseases, and demonstrate proof-of-principle for delivery to the retina and regulation of the gene.
These are essential features required for a safe and effective product.
Hence, the encouraging preclinical results mean that the RetinoStat programme is on track for clinical development in 2004.
Age-related macular degeneration ('AMD') and diabetic retinopathy ('DR') affect approximately 30 million people in the developed world and the market potential is in excess of $1.0 billion.
In both AMD and DR, blindness is caused by the defective formation of new blood vessels in the retina.
In AMD, new blood vessels extend from the inner retina beyond the inner limiting membrane, which leads to haemorrhaging and distortion of the specific area of the retinal surface responsible for sharp, central vision.
In DR, a similar process occurs however, the new blood vessels appear on the vitreous surface of the retina causing excessive accumulation of fluid or 'oedema', which blurs vision and causes retinal haemorrhage.
RetinoStat is designed to halt this aberrant growth of blood vessels before it begins.
Currently, the only available treatments for AMD and DR are limited and tend to only slow the diseases' progression.
The collaboration between Oxford BioMedica and the Institute of Ophthalmology was initiated in May 2002.
It is a research and development agreement using the company's proprietary technology to develop novel treatments for vision loss.
RetinoStat comprises a LentiVector gene delivery system expressing an angiostatic gene under the control of Oxford BioMedica's Hypoxia Response Element, which promotes gene expression under low oxygen conditions.
Commenting on the results chief executive, professor Alan Kingsman said, "We are delighted to be presenting at the major vision conference of the year.
"Our RetinoStat data are exciting and this forum allows us to describe the results to the widest possible audience including potential commercial partners.
"This is the first public statement of progress from the collaboration and we look forward to more developments in the coming months".
Robin Ali, head of the ocular gene therapy group at the Institute of Ophthalmology said: "We are very pleased to be working with Oxford BioMedica.
"Our recent results support the use of their LentiVector and Hypoxia Response Element technologies for the treatment of ocular disorders and pave the way for advancement to clinical trials".
Background to age-related macular degeneration ('AMD') and diabetic retinopathy ('DR').
AMD is now one of the major debilitating diseases of the ageing population.
About one in six people between the ages of 55 and 64 will develop AMD while one in four between 64 and 74 will be affected.
One in three over the age of 75 will be affected.
Each year 1.2 million of the estimated 12 million Americans with macular degeneration will suffer severe central vision loss.
Each year 200,000 individuals will lose all central vision in one or both eyes due to AMD.
DR is the commonest cause of visual loss in people of working age and the predominant cause of economic loss due to visual impairment.
Over 40% of people with insulin dependant and 20% of people with non-insulin dependent diabetes eventually succumb to diabetic retinopathy.
In the US alone, where an estimated 16 million people have either type I or II diabetes, about 600,000 have retinopathy.
Direct and indirect costs of diabetic retinopathy totalled more than $2.8 billion in 1996.
2% of insulin dependent diabetics are totally blind, many of them in the younger age group.
