Partners announce milestone in avian transgenics project
Viragen, Roslin Institute (Scotland) and Oxford BioMedica have made a noteworthy breakthrough in their pioneering project to develop avian transgenic biomanufacturing, reporting a functional humanised antibody protein incorporated in the whites of eggs laid by a transgenic hen.
The project is designed to develop the chicken into a pharmaceutical bioreactor that can meet the growing need for protein-based human therapeutics, and is being developed as an efficient and economical alternative to standard biomanufacturing techniques, having apparent advantages in ease of scale-up, lower costs of production and quality of product produced.
The therapeutic protein, successfully expressed using Oxford BioMedica's LentiVector gene delivery system, is a novel structure of an antibody in Viragen's product portfolio, being designed to target malignant melanoma. Three other protein-drug candidates are included in ongoing avian expression studies to demonstrate the breadth of its capabilities, including two commercially marketed products, each of which realises more than $2bn in annual sales.
Viragen and Roslin confirmed qualitative and quantitative detection and recovery of humanised antibody from the eggs. The analysis indicates that the expression levels measured are significantly higher than any previously published results for a therapeutic protein produced from an avian transgenic line.
The project's scientific leader, Roslin senior scientist Dr Helen Sang, said: 'we previously published results demonstrating ubiquitous expression throughout the entire bird. This latest result indicates that we have now been able to target the expression so that the functional protein is synthesised as a component of the egg white.'
Viragen's president and ceo, Charles A. Rice, added: 'we plan to demonstrate that our avian-manufactured products are glycosylated, which is critical to the functionality, safety and tolerability of such biopharmaceuticals. Many existing protein drug products are not glycosylated by virtue of their manufacturing process, which can lead to adverse immune responses and a significantly shorter half-life in the body. We aim to take such proteins and create improved versions, which should be better tolerated, possibly be dosed in lower quantities, and hopefully would be beneficial to the safety of the patients.'
The project has been funded in part from a grant awarded by the Scottish Executive's SPUR Plus Program, designed to support significant technological advances being made in Scotland.