Symphogen

Genentech, Inc.: Collaboration pact with Genentech which enables both companies to utilize Symplex technology to help discover new antibodies against three undisclosed infectious disease targets.

Meiji Seika Kaisha, Ltd: Sym006 development and license agreement with Meiji Seika that establishes a collaboration of research, development, and commercialization.

Biovitrum: A co-development and commercialization agreement with Biovitrum for Sym001. The United States Food and Drug Administration granted an orphan drug designation to Sym001.

NIAID/NIH: Sym002 developmental grant with the National Institutes of Health for a recombinant polyclonal antibody against smallpox. The grant enables Symphogen to complete pre-clinical development of Sym002, which allows submission of an Investigational New Drug application for new safety studies.

Recombinant monoclonal antibody mixtures mimic the diversity, specificity and binding capability of the natural immune system and increase the likelihood of the rapid elimination of the desired antigens. IgG antibodies are typically used due to their effectiveness in binding to many kinds of pathogens as well as protecting the body against the pathogens by immobilization, complement activation, opsonization for phagocytosis and neutralization of their toxins.^[2]

Multi-clonal antibodies developed at Symphogen are mixtures of monoclonal antibodies, where each of the mAbs binds specifically to one unique epitope of the target. Technically, Symphogen products are not polyclonal antibodies, since the latter bind to different epitopes of the target molecule. By producing mixtures of the monoclonal antibodies, Symphogen avoids the major drawback of the polyclonal antibodies, which quality is difficult to control due to the diversity in their biophysical characteristics and biological activity.

According to Symphogen, their proprietary monoclonal antibody mixtures reflect both the diversity of immunoglobulins and specificity of monoclonal antibodies. It is possible to produce an unlimited supply of these antibodies using traditional large-scale biological manufacturing techniques; these antibodies are produced with no risk of viral or prion transmission according to Symphogen. This new class of therapeutic antibodies could be effective in treating complex diseases such as cancer for it allows the combination of several treatment modalities in one drug.^[4]

Recombinant multi-clonal antibodies, or mixtures of mAbs, could be advantageous for the following reasons:

• less sensitive to target diversification such as viral escape mutants
• hit multiple targets simultaneously
• create large immune complexes that activate effector functions
• create a higher density of antibodies on target surfaces enhancing downstream effector functions such as complement lysis, phagocytosis and antibody-dependent cell-mediated cytotoxicity

Symplex Technology is a process used to discover antibodies that are customized from plasma cells for a particular therapeutic application, and it involves direct isolation of the antibody genes from the immune system.^[5]

Symplex Process:

1. Immune cells are isolated from the spleen of mice or purified from human blood
2. B-lymphocytes are separated using differences in cell densities
3. Cells are individually sorted and antibodies are isolated
4. Symplex PCR uses reverse transcription^[6]
5. Heavy and light chains are amplified and conservatively paired back together in natural configuration
6. Each antibody is cloned, placed into a bacterial vector and stored in a library
7. Antibodies are placed into a well (repertoire arraying) and the DNA is extracted and prepared
8. DNA is transected to make protein and antibodies are cloned
9. The cloned antibodies are placed into wells and specifically chosen for further development based on antibody expression
10. Antibody of choice from the original gene pairs (conjugate pairs) is chosen by screening
11. A fully human antigen-specific antibody is produced

Sympress Technology is the manufacturing platform used to produce recombinant polyclonal antibodies in high yields. This technology enables the production of consistent mixtures of polyclonal antibodies with high batch-to-batch consistency at an industrial scale.^[7]

Sympress Process:

1. Antibodies are encoded on plasmids using Chinese hamster ovary cell lines
2. Cells undergo transfection
3. Cells where the antibody is most highly expressed are selected through fluorescent tagging
4. Cell lines are preserved and stored in cell banks
5. The individual cell lines encoding the highest quality antibodies are mixed and produced in high yields

Sympress I Technology has been used to develop the product Sym001. Recently, Sympress II Technology has been developed, and it uses random gene integration to improve the expression yield.