We use two protein engineering technologies, Site-Specific PEGylation and ImmunoFusion Protein technology to create our proprietary products. Both technologies increase a protein's effective size and slow its clearance from the body. Both technologies preserve biological activity of the therapeutic protein by targeting attachment of polymers or protein domains to nonessential regions of the protein. Historically, loss of biological activity and product heterogeneity have been the two most common problems encountered in the development of long-acting protein pharmaceuticals. The targeted protein modification technologies we use overcome these problems.
Site-Specific PEGylation allows a protein to be selectively modified with the polymer polyethylene glycol (PEG) at a single, unique, pre-determined site. The site of PEGylation potentially can be any amino acid position in the protein and can be varied depending upon the protein. By targeting attachment of the PEG molecule to a nonessential site in a protein, we are able to create PEGylated proteins that are homogeneously modified and have minimal loss of biological activity. Because our PEGylated proteins are homogeneously modified, they are readily purified using scalable manufacturing methods and possess reproducible biological activities. The general technology used to create site-specific PEGylated proteins can be used to selectively modify proteins with other types of ligands such as starches, lipids and nucleic acids.
ImmunoFusion Protein technology takes advantage of the modular structure and long circulating half-lives of human immunoglobulins (antibodies). Company scientists use recombinant DNA methods to covalently fuse therapeutic proteins to the specific domains of human immunoglobulin gamma proteins (IgGs). IgGs are abundant proteins that have circulating half-lives of up to 21 days in humans. We are evaluating several cytokine-immunoglobulin fusion proteins that possess the high potency and specificity of their parent cytokine molecules, and the long circulating half-life of the immunoglobulin domain.