"We believe that our plant-produced insulin will allow us to supply this expanding market and reduce capital costs by 70 per cent and cost-of-goods by more than 40 per cent compared with current production methods," said Andrew Baum, President and CEO of SemBioSys Genetics.
"Our team has already made progress on the next development objective in this program, which is to achieve commercial levels of insulin expression in safflower, our commercial plant system."
The article details the proof-of-concept study performed using transgenic Arabidopsis thaliana, the Company's plant model system, to determine the feasibility of expressing and recovering biologically active insulin.
Using the Stratosome Biologics System, recombinant human insulin was expressed and accumulated in transgenic seed.
Plant-derived insulin accumulates to significant levels in the transgenic seed (0.13 per cent total seed protein) and can be enzymatically treated in vitro to generate a product with a mass identical to that of the predicted product, insulin.
The biological activity of this product in vivo and in vitro was established using an insulin tolerance test in mice and phosphorylation assay performed in a mammalian cell culture system, respectively.
The Stratosome Biologics System also simplifies the recovery and purification processes creating significant cost reductions in large-scale production.
SemBioSys is now focused on insulin expression in safflower, its commercial plant production system.
The company added that development was underway to achieve commercial levels of insulin expression in safflower to provide a scalable and economical source of insulin to meet the future growth of insulin demand.
The worldwide insulin market is immense, with sales of over $5 billion (€4.3 billion) in 2004 and yearly growth of almost 10 per cent. Furthermore, the market is highly concentrated, with three companies monopolising available market share.
Novo Nordisk, with 32 per cent (e.g. Novolin - $1.1 billion in 2004 - and Novolog), Eli Lilly, with 54 per cent (Humalog and Humulin, each grossing about $1 billion) and Sanofi-Aventis, with a 16 per cent share of the worldwide market (Lantus, about $0.8 billion).
However, human insulin has a very short shelf life and is extremely toxic when administered in excessive doses. This requires diabetic patients to inject themselves with insulin doses several times per day, a procedure that is both painful and impractical.
Pharmaceutical companies have thus been encouraged to become more innovative in order to better respond to the needs of diabetics.
In particular, there have been calls for companies to develop insulin with different durations of action (prolonged, intermediate, short, mixed) and alternatives to subcutaneous injection delivery, thereby allowing treatments to be customised to suit the individual patient's needs.
The article, titled: "Transgenic expression and recovery of biologically active recombinant human insulin from Arabidopsis thaliana seeds," appears in the January 2006 edition of the Plant Biotechnology Journal.