The clotting factor has been developed by LFB Biotechnologies and US partner GTC Biotherapeutics as they seek a lower-cost alternative to current treatments for haemophilia and other bleeding disorders. While producing drugs in the milk of transgenic animals offers significant cost advantages over traditional manufacturing processes, both in terms of reduced solvent use and potential yields, additional steps are required to ensure that a high purity compound is produced.
BAC's CaptureSelect platform uses hyper-variable single chain antibody fragments that can be directed to interact with very high-affinity with any particular protein. The selected fragment can then be mass-produced using BAC's proprietary strain of the yeast Saccharomyces cerevisiae, prior to immobilization on a suitable chromatography matrix. The new project, financial terms of which have not been disclosed, will seek to develop a ligand that has high-affinity for Factor VIIa-specific for application in purification steps during LFB's bioprocess operations.
Laurens Sierkstra, BAC's CEO, explained that the CaptureSelect "technology platform enables us to produce ligands that are not only highly specific for the target protein, but will generate a very pure product in a single purification step." He added that BAC was aiming to develop a ligand that can help streamline LFB's purification processes. LFB's technology director, Sami Chtourou said "the collaboration with BAC for the development of a specific ligand for our recombinant factor VIIa is a significant step for the downstream process of this strategic project."
In 2007, the only commercially available recombinant factor VIIa product NovoSeven, which is produced by Denmark's Novo Nordisk, generated revenues of 5.86bn Danish kroner ($1.2bn), up 10 per cent on the previous year. Unsurprisingly LFB and GTC are not the only companies to be targeting this lucrative market. One potential competitor is US firm Maxygen, which announced plans to initiate clinical trials of MAXY-VII product in the next few months. Transgenic protein purification market
Earlier this year, BAC entered into a deal to supply Hematech, a US firm that specialises in antibody production in transgenic cows, with a bovine IgG scavenging ligand-based chromatography media. The agreement, which is ongoing, will also see Hematech incorporate IgSelect, an off-the-shelf product made by BAC and partner GE Healthcare, into its setup. To date, very few drugs that are produced using transgenic organisms have reached the market, the notable exception being GTC Biotherapeutics' antithrombin factor Atryn, which received European approval in June 2006 and is currently under review by the US Food and Drug Administration (FDA).
More recently, a European Medicines Agency's (EMEA) committee recommended against clearing the hereditary angioedema drug Rhucin (recombinant C1 inhibitor), produced in the milk of transgenic rabbits, on the basis that there was insufficient evidence of its risk/benefit profile.
Subsequently the drug's developer, Dutch group Pharming appealed this decision and, more recently has moved to secure patent rights to the production technology through its deal with Advanced Cell Technology (ACT).